Operational Medicine 2001
United States Naval Hospital Corpsman 3 & 2 Training Manual
NAVEDTRA 10669-C June 1989

Hospital Corpsman 3 & 2: June 1989

Chapter 11: Preventive Medicine

Naval Education and Training Command
Peer Review Status: Internally Peer Reviewed

Introduction

In the Navy Department the maintenance of all personnel in the highest possible state of health and physical readiness is the responsibility of the commanding officer. The commanding officer, in turn, looks to the Medical Department for advice, recommendations, and establishment of standards.

The old adage "An ounce of prevention is worth a pound of cure" is an excellent guide to modern preventive medicine practice and certainly holds true in the Navy, where we are interested in keeping a man on the job rather than on the sicklist.

No matter what duties hospital corpsmen are assigned to, a phase of their work will always be aimed at preventing injury and disease and maintaining the health of their shipmates. This chapter will familiarize you with the basics of preventive medicine and help you understand the principles of maintaining good health in everyday living. 

Personal Hygiene

Because of the close living quarters in the Navy, particularly aboard ships, personal hygiene is of utmost importance. Disease or ill health can spread and rapidly affect an entire compartment or division in a short period.

Personal hygiene promotes health and prevents disease. Some military personnel tend to be lax in paying strict attention to their personal hygiene. As a corpsman you will be responsible for recognizing signs of neglect, either at sick call or in the performance of your duties as a Medical Department Representative (MDR) and petty officer. You must also be especially scrupulous in your own personal hygiene, both to set a good example and to prevent the direct acquisition or spread of illness from patient and to yourself.

Corpsmen are responsible for presenting health education training programs to the personnel of their unit. In addition to stressing the basics of personal hygiene, they must draw attention to proper foot care, exercise, nutrition, and sleep as important factors in maintaining good health.

Basics of Personal Hygiene

Uncleanliness or disagreeable odor will surely affect the morale of your shipmates. A daily bath or shower will assist in the prevention of body odor and is absolutely necessary to maintain cleanliness. The daily shower also aids in the prevention of common skin diseases. Shampoo the hair at least once weekly, using a commercial shampoo of your choice. The importance of washing your hands at appropriate times cannot be overemphasized. Always wash your hands with soap and water after using the toilet and before meals.

Proper Foot Care

Proper foot care is a vital factor in the overall performance of personnel, both ashore and afloat. Remember the foot gear you were issued in boot camp? If the fit was not perfect, the following weeks were most unpleasant for you. Proper fitting of shoes and socks is just one aspect of the problem. In military exercises, especially ashore, the feet are exposed to tremendous stress. The corpsman's job of monitoring foot conditions will be made easier if the unit's personnel have been taught to clean and dry their feet regularly, especially between the toes; to use foot powder to deter chafing and to promote absorption; to change socks and boots or shoes regularly, especially in wet environments; and to have foot disorders medically evaluated and treated promptly to prevent potentially disabling problems.

Proper Exercise

Proper exercise increases the body's resistance to certain diseases, promotes its digestive and excretory function, and decreases one's risk for atherosclerotic heart disease (the nation's leading cause of premature death and disability). Improved muscle tone and physical endurance help the individual to fulfill military tasks and raise the level of self-confidence as well as improve the psychological disposition. Working outside in the fresh air enhances the value of exercise and hastens acclimatization to new environments. Smoking and overindulgence in food and drink are detrimental and defeat the purpose of exercise.

Proper Sleep

During sleep the body recharges its nervous energy, repairs damaged cells, and regains its bounce. It is important to sleep undisturbed at regular hours and long enough to awaken refreshed. Continued physical and mental fatigue is detrimental to the maintenance of good health.

Proper Nutrition

Proper nutrition is essential to supplying the body with all the elements it needs to function. Energy for activity and proteins, minerals, and vitamins for growth are all supplied by a proper diet.

Immunization

Protection of Navy and Marine Corps personnel against certain diseases before exposure to infection is called prophylactic immunization. Prophylactic immunization is limited to diseases that are very serious and for which effective and reliable immunizing agents have been developed.

While unit commanding officers are responsible for ensuring that all military and nonmilitary personnel under their jurisdictions receive the required immunizations and that appropriate records of such immunizations are maintained, the actual performance of these tasks is the responsibility of the Medical Department. (See BUMEDINST 6230.1 series, NAVMEDCOM- NOTE 6230, Immunization Requirements (latest issuance), and other appropriate guidelines.

Preservation and Disposition of Biologicals

Store and distribute the yellow fever vaccine at temperatures below 0° C (32° F). The oral poliovirus vaccine requires particular care to preserve its potency. Storage should be in the frozen state at a temperature of -14° C (7° F). Thawing or evidence of thawing during shipment renders the shipment unacceptable for use. Store all other biologicals at temperatures between 2° and 8° C (35.6° to 46.4° F), and make sure they do not freeze.

Do not accept shipments for use if there is a change in the physical appearance or evidence suggestive of bacterial contamination or growth. Such shipments will be withheld from issue and use. Forward a request for disposition instructions to the supply source and an information copy to NAVMEDCOM, citing identifying data, circumstances, and deficiencies noted.

Empty containers of all living vaccines should be handled as infectious wastes. Before these items are discarded, they should be burned, boiled, or autoclaved.

Do not use immunizing agents beyond the stated expiration dates, unless an extension is specifically authorized by NAVMEDCOM and DPSC.

Vaccination Precautions

Before injecting a biological product, determine whether the individual has previously shown an unusual degree of sensitivity to a foreign protein. Individuals who give a history of sensitivity to an immunizing agent usually will be exempted from the immunization by a medical officer. Persons with a significant allergy to eggs or fowl should not be given vaccines prepared by cultivation in eggs (e.g., typhus, influenza, yellow fever, or measles vaccines). Record severe individual reactions or sensitivities to any biological agent or drug in the immunization record, indicating the offending substance, its lot number and manufacturer, the date administered, and the severity of the reaction. In addition, note any hypersensitivity to drugs or chemicals known to exist on a separate SF 600.

Prior to the administration of any immunizing agent, make provisions for immediate first aid and medical care of any anaphylactoid reaction that may occur. A military or civilian member of the Medical Department who is certified in emergency resuscitative techniques shall be present. An emergency tray containing material for immediate treatment of serious anaphylactic reactions, including a tourniquet and syringe containing a 1:1,000 aqueous solution of epinephrine, should also be on hand. Consult NAVMED P-5052-15 series and local guidelines for other recommended materials and additional information regarding medical emergencies.

In severe reactions, symptoms appear immediately. These can include blotchy redness and hives of the skin; a feeling of a tight throat, bronchospasm, and dyspnea; vomiting, nausea and abdominal pain; rapid pulse; and the patient feeling very apprehensive and possibly disoriented. The lips, tongue, and eyelids may be swollen; circulatory and respiratory collapse can occur. Treatment must be rapid and exact to stop the progress of shock. Immediately give 0.5 ml of epinephrine 1: 1,000 subcutaneously (SC) in any available area without stopping to prepare the immunization injection site. Put a tight tourniquet proximal to the injection site (on the side toward the heart) to prevent further absorption of the material. Start an intravenous infusion using a 5 percent dextrose/saline solution so that access is available for other medications if needed. Make sure the patient is under a physician's care as rapidly as possible.

Whenever you notice local or constitutional reactions of unexpected severity or frequency, local infection, abscess formation not traceable to errors in techniques of administration, or other significant manifestations that may be due to the use of a biological product, discontinue administration of the lot and request instructions regarding the disposition of the suspected materials. Until you receive a reply, keep all open and unopened packages in the lot under proper storage conditions.

Precaution: Before administering any live virus vaccine to a female, except the oral poliovirus vaccine, ask her if there is any chance that she may be pregnant. If her answer is affirmative, a medical officer will probably grant a temporary exemption, since live virus vaccines are contraindicated during pregnancy.

For further information on waivers and ex- emptions, consult NAVMED P-5052-15 series, NAVMEDCOMNOTE 6320 (latest issuance), and BUMEDINST 6230.1 series.

Aircrew members shall not fly for a minimum of 12 hours (preferable 24 hours) after receiving any immunization except the oral poliovirus and smallpox vaccines.

Intervals

The prescribed time intervals between individual doses of a basic immunization series will be regarded as optimal and will be adhered to as closely as possible. If delays prevent completion of a series within the prescribed time, administer the next dose, or doses, at the earliest opportunity. A new series will not be given. Minimum intervals between doses will not be reduced under any circumstances. When a basic series has been completed, as evidenced by proper entries on an official immunization record, the need for another basic series of the agent is eliminated. A single stimulating (booster) dose will suffice. There should be a minimum period of 30 days between doses of different live virus vaccines, unless a medical officer directs otherwise.

Routine Immunizations

Manufacturer's inserts in the vial packages will specify the route of administration of the vaccine, e.g., intramuscularly (IM) or subcutaneously (SC). These directions must be followed accordingly.

Do not mix two or more immunizing agents in a vial or syringe for the purpose of permitting a single simultaneous injection; the agents may be biologically or physically incompatible. Always read the package insert before administering any immunizing agent.

When there is insufficient time to permit completion of a required basic series prior to travel, do not delay travel for any dose except the first dose of the series.

Smallpox Vaccine

The naturally occurring disease smallpox has been eradicated around the world. Thus, routine periodic vaccination of military personnel is currently no longer justified. Navy and Marine Corps personnel will be immunized for smallpox only in certain situations when they can be isolated from the general population. Current policy thus limits the administration of the smallpox immunization to the period of time during recruit training and officer indoctrination programs.

Method - To avoid a large lesion with the increased danger of secondary infections, inject the virus by the multiple pressure method (do not cause bleeding) into as small an area as possible. The area should not cover more than one-eighth of an inch in any direction. To avoid infection, use aseptic technique. Cleanse the area with sterile cotton and alcohol or acetone, and permit it to dry thoroughly prior to vaccination. Failure to wait for the antiseptic to dry may result in inactivation of the virus. Allow the vaccine to dry for 3 to 5 minutes without exposure to sunlight, when wipe off the excess with sterile cotton or gauze. A specifically equipped jet injection gun may also be used by trained personnel. Inspect the vaccination site 6 to 8 days after vaccination and interpret the response as follows:

1. A primary vaccination, if successful, shows a typical vesicle. If none is observed, check the vaccination procedures and repeat the vaccination with another lot of vaccine until a successful result is obtained. Record reactions as successful or unsuccessful.

2. Following revaccination, two possible responses may be noted:

   • Major reaction-A vesicular or pustular lesion, or an area of definite palpable induration or congestion surrounding a central lesion, which may crust or ulcer. This reaction indicates that virus multiplication has most likely taken place and that the revaccination is successful.

   • Equivocal reaction-Any other reaction should be regarded as equivocal. These responses may be the consequence of immunity adequate to suppress virus multiplication or may represent only allergic reactions to an inactive vaccine. If an equivocal reaction is observed, recheck the revaccination procedures and repeat the revaccination one time.

Typhoid Vaccine (killed and dried with acetone)

The typhoid vaccine consists of one 0.5 ml dose which is given subcutaneously. The vaccine will be administered to all active duty personnel at their first permanent duty station. Alert Forces will be revaccinated every 3 years. Never give the typhoid vaccine intradermally.

Tetanus-Diphtheria Toxoid

The basic series consists of two 0.5 ml primary injections, given intramuscularly 1 to 2 months apart. A third reinforcing injection of 0.1 ml is given approximately 12 months after the second dose when there is reliable evidence that the person has never received the immunization prior to entering the service. Reimmunization is required every 10 years or may be ordered after a serious injury or burn.

Trivalent Oral Poliovirus Vaccine

This live trivalent vaccine is given orally either in distilled unchlorinated water, in simple syrup, or by a sterile medicine dropper. Keep the vaccine frozen until needed and use only for 7 days after the bottle is opened. Never refreeze the vaccine. Give a single dose of trivalent oral poliovirus vaccine to all recruits or officers who have not had it within 3 days of recruit training or during officer indoctrination programs.

Influenza Vaccine

The influenza virus vaccine must be given annually, at the start of the respiratory disease season (usually October in the northern hemisphere), to all recruits, officer candidates, midshipmen, and members of the Navy and Marine Corps. The vaccine is sometimes offered to other personnel and dependents on a voluntary basis. All active duty Navy and Marine Corps personnel are designated to receive the immunization. Unless otherwise specified, give one injection of 0.5 ml intramuscularly.

Yellow Fever Vaccine

This vaccine is given to all Navy and Marine Corps Personnel and also to all other DOD personnel who must travel to a yellow fever endemic area. A single 0.5 ml injection is given subcutaneously. If the vaccine is received in concentrated form, it must be diluted in a 1:10 ratio. Reimmunization is required every 10 years.

Cholera Vaccine

This vaccine will only be given on a case by case basis to personnel who must travel to countries still requiring the vaccine. A 0.5 ml dose given either subcutaneously or intramuscularly is required. Reimmunization, if required, will be given at 6-month intervals.

Plague Vaccine

The basic series of plague vaccine consists of two doses. The first is 0.5 ml given intramuscularly and the second is 0.2 ml given intramuscularly 3 months after the first dose. This vaccine is given to all Navy personnel assigned to operational billets with the Fleet Marine Forces. It may be given under special circumstances in very high plague endemic areas or for high risk occupational groups. Reimmunizations are given at 6-month intervals to all personnel who must travel to or reside in a plague-infested areas.

Special Immunizations

Besides the routine immunizations given to personnel, you may be responsible for the administration of additional vaccines as determined by the Surgeon General.

Measles and Rubella Vaccines

Administer the measles-rubella vaccine, or measles or rubella vaccine(s), to all male recruits early in recruit processing or training. It is permissible to wait for the results of rubella or measles antibody titers prior to administering the appropriate vaccine(s) to susceptible individuals only, provided that a reliable screening test is used and provided that such susceptibility testing does not unduly delay vaccine administration. Such susceptibility testing is not mandatory for male recruits and should be done only where practical and cost-effective. Female recruits will be asked about possible pregnancy and will undergo rubella antibody testing and a screening test for pregnancy prior to administration of any vaccine containing the rubella antigen. The measles-rubella vaccine, or measles or rubella vaccine(s) will be subsequently administered to susceptible individuals only. Administer the rubella vaccine to all susceptible persons engaged in health care, regardless of age or sex. Demonstrated rubella titers or a documented history of prior receipt of the rubella vaccine or the measles-mumps-rubella vaccine is adequate evidence of immunity for such individuals, regardless of age or sex. Potentially pregnant females will be asked about possible pregnancy prior to administration of the rubella vaccine.

Mumps Vaccine

Administer the mumps vaccine in dosages as recommended by the manufacturer to all probably susceptible persons engaged in health care. A previous history of mumps or a documented history of prior receipt of the live virus mumps vaccine or the measlesmumps-rubella vaccine is adequate evidence of immunity for such individuals. Institute this policy in health care settings for all probably susceptible personnel, regardless of age or sex. Ask potentially pregnant females about possible pregnancy prior to administration of the mumps vaccine.

Human Diploid Cell Rabies Vaccine

Individuals in occupational groups at high risk for contact with potentially rabid animals or laboratory specimens potentially contaminated with the rabies virus should receive the human diploid cell rabies vaccine (individual booster doses) in a regimen as recommended by the Advisory Committee on Immunization Practices (ACIP) and the manufacturer. Individuals who have received this regimen still require the postexposure human diploid cell rabies vaccine prophylaxis in conjunction with appropriate rabies immune globulin, in accordance with the most current recommendations of the ACIP and the manufacturer.

Hepatitis B Virus Vaccine

The hepatitis B virus vaccine should be administered to individuals in "high risk" situations characterized by frequent contact with human blood or blood products (usually associated with certain health care occupational specialties). The dosage regimen consists of three doses of 1.0 ml each, administered intramuscularly; the second dose is given 1 month after the first dose, and the third dose is given 6 months after the first dose.

Adenovirus 4/7 Vaccine

Administer adenovirus 4/7 vaccines to all male recruits within the first 3 days of recruit processing or training. If epidemiologically indicated, and as recommended by the cognizant area Navy Environmental and Preventive Medicine Unit, adenovirus 4/7 vaccines may be administered to nonpregnant female recruits and to student officers in some settings. However, there is no current epidemiologic evidence to suggest that these vaccines are routinely needed in most settings outside the recruit center. NOTE: Current (1987) military policy mandates testing of all recruit populations for the presence of the antibody to the HIV (HTLV-3) virus, which is associated with the acquired immune deficiency disease (AIDS). Because there is concern that live virus vaccines may adversely affect recruit individuals who unknowingly have an altered or decreased immune system, it is current policy that any live virus vaccine, with the exception of adenovirus, will not be administered to recruits until the results of the HIV antibody testing are known. These live virus vaccines include those against yellow fever, measles, rubella, polio, and smallpox. As a result of this policy, immunization schedules in Navy and Marine Corps recruit centers and officer indoctrination centers have had to be altered from previous long-standing recommendations.

Record of Immunizations

The yellow PHS Form 731 is prepared for each member of the Armed Forces. Enter the data by hand, rubber stamp, or typewriter. The day, month, and year of each immunization given will be expressed in this order. Indicate the day in Arabic numerals; the month spelled out or abbreviated, using the first three letters of the word; and the year expressed in arabic numerals, either by four digits or by the last two digits. The member's Social Security number must be listed for identification purposes. Entries for smallpox vaccines should indicate whether freeze-dried or liquid vaccine was used. Make sure the origin and batch number are recorded for yellow fever and smallpox vaccines. Entries for smallpox, yellow fever, and cholera must be authenticated by the DOD Immunization Stamp and the actual signature of the medical officer or a specifically designated representative. All other immunizations are authenticated by initialing. Entries for tetanus toxoid alone will be recorded as "TT." Entries based on prior official records will have the following statement added: "Transcribed from official United States Department of Defense records." Such entries in the case of smallpox, yellow fever, and cholera shall be validated by the signature of a medical officer or a specifically designated representative.

An Immunization Record, SF 601, will be started for all personnel entering the Navy. It will be prepared in accordance with chapter 16 of the Manual of the Medical Department and will contain the Social Security number of the member for identification purposes.

Communicable Diseases

Communicable diseases, as the name implies, are those diseases that can be transmitted from one host to another. They may be transmitted directly or indirectly to a well person from an infected person or animal, or through the agency of an intermediate animal host, vector, or inanimate object. The illnesses produced result from infectious agents invading and multiplying in the host, or from their toxins (poisons)

Transmission of Infectious Agents

Any means that brings an infectious agent to a susceptible human host and results in an exposure to the agent is a method of transmission. Essentially, there are two types of transmission, direct and indirect.

1. DIRECT TRANSMISSION-The transfer, without delay, of an infectious agent to a point (portal of entry) on a receptive host where it can enter the body. Examples of direct transmission are:

   1. Direct contact-Touching, kissing, or sexual intercourse.

   2. Direct projection-Droplet spray from coughing, spitting, talking, etc.

   3. Direct exposure-The contact of susceptible tissue with soil, vegetable matter, etc., containing infectious agents.

2. INDIRECT TRANSMISSION-Examples of the three types are listed below.

   1. Vehicle-borne-Infectious agents are transferred and deposited on a host at a suitable point of entry by fomites (nonliving, inanimate materials or objects, e.g., toys, bedding, utensils, food, and drink). The infectious agents must be present on the fomite; it may or may not have reproduced.

   2. Vector-borne-Infectious agents are transferred to a susceptible host by insects. There are two types of vector-borne transmission.

      1. Mechanical-The infectious agent is acquired when an insect's body parts come into contact with contaminated materials, objects, or infected persons, and then make contact with a susceptible host.

      2. Biological-The infectious agent, after being acquired by an insect, must go through biological changes in the insect before it is capable of producing an infection or disease when deposited on or in a susceptible host.

   3. Airborne-There are two methods of indirect airborne transmission, by droplet nuclei (from cough or sneeze) and dust. In both cases, the infectious agent may remain airborne for long periods of time.

Reporting of Communicable Diseases

An important step in the control of communicable disease is proper reporting. Instructions and requirements for reporting to local, state, national, and international health authorities are found in the preface of Control of Communicable Diseases in Man (NAVMED P-5038). In addition, cases in the Navy and Marine Corps must be reported as required by NAVMEDCOMINST 6220.2 series, Disease Alert Reports.

Navy references concerning prevention, control, diagnosis, treatment, etc., include Control of Communicable Diseases in Man (NAVMED P-5038), Technical Information Manual for Medical Corps Officers (NAVMED P-5052), and Manual of Naval Preventive Medicine (NAVMED P-5010). Selected communicable diseases are discussed in NAVMEDCOM/BUMED instructions.

Assistance with communicable disease investigation, reporting, and prevention may be obtained by contacting the area Navy Environmental and Preventive Medicine Unit.

Disease Alert Reports

The Disease Alert Report provides responsible commands with information necessary to minimize interruption of Navy and Marine Corps operations and to protect the health of personnel in the communities and areas in which they live. These reports are particularly applicable for reporting outbreaks of selected diseases that may affect operational readiness; be hazardous to the community; be spread through transfer of personnel; be an international quarantinable disease; or be of such significance that inquiry may be made of the Naval Education and Training Command or higher authority.

The initial Disease Alert Report will be submitted by the commanding officer with primary responsibility for the health and welfare of the affected individual. These reports are submitted either by speedletter or routine message. However, for all diagnoses indicated by an asterisk (*) in NAVMEDCOMINST 6220.2, or if, in the judgment of the commanding officer, more timely notification of the diagnosis is necessary to ensure expeditious implementation of preventive measures, submit a priority message. For more detailed information, refer to NAVMEDCOMINST 6220.2 series.

Communicable Diseases of International Importance

Acquired Immune Deficiency Syndrome (AIDS)

The onset of AIDS is gradual and presents symptoms that are nonspecific, e.g., fatigue, fever, chronic diarrhea, loss of appetite, weight loss, and involvement of the lymph nodes. Underlying deficiency of the body's immune system allows for secondary "opportunistic" diseases (bacterial, viral, or parasitic secondary infections) to develop. On some occasions, the first presentation is a severe, life-threatening opportunistic disease. Detection of AIDS may depend on the surveillance of certain diseases, which may be predictive of a body immune deficiency in the absence of a known immune deficiency.

A serologic test for antibodies to the AIDS virus is available and is now used for screening for evidence of past or present infection among civilian and military personnel.

The infectious agent is a virus designated as either human immune virus (HIV), human T- lymphotropic virus, type III (HTLV-3), or lymphadenopathy-associated virus (LAV). These are considered to be the same virus. The reservoir is man. The incubation period is unknown; evidence suggests from 6 months to 5 years with an average of about 2 years for transfusionassociated cases.

Epidemiologic evidence indicates that AIDS is primarily transmitted by promiscuous sexual contact (especially homosexual intercourse), sharing unclean needles, through contaminated blood transfusions or blood products, and transplacental transfer. It also may occur with heterosexual con- tact with high risk populations, e.g., prostitutes in the United States and overseas. This is not to say that only these populations are at risk; all personnel who engage in sexual activity with an unknown partner are at some level of risk.

The period of communicability for AIDS is unknown. It may extend from the asymptomatic period until the appearance of opportunistic diseases.

There is no specific treatment for the immune deficiency. Treatment is directed toward the opportunistic diseases that result from AIDS. Patients are treated in hospitals with blood and body fluid precautions. They require intensive medical support and prognosis for long-term survival is poor.

Preventive measures are very important. Educate personnel that having promiscuous sexual behavior and multiple random sexual partners increases the probability of contacting AIDS.

Personnel who are asymptomatic of AIDS but antibody positive should not donate blood, should not be sexually promiscuous, and should be intensively counseled about what this condition means.

Amebiasis

This intestinal infection may be asymptomatic; however, symptoms can include mild abdominal discomfort, chills, fever, diarrhea with blood or mucus, and abscesses of the liver, lung, or brain. The diagnosis is established by microscopic observation of cysts or trophozoites in fresh or preserved stool specimens or by aspirate from abscesses or tissue. The disease occurs worldwide, but is more common in areas with poor sanitation and health education.

The infectious agent is the single-celled intestinal parasite Entamoeba histolytica. The reservoir is an infected person, usually an asymptomatic cyst passer. Outbreaks are usually spread by the soiled hands of food handlers, contaminated water, hand-to-mouth transfer of feces, flies, and contaminated fruits and vegetables. Patients with acute dysentery are not very communicable, as they do not pass cysts in their stools and any trophozoites passed are fragile. The average incubation period is 2 to 4 weeks. Amebiasis is communicable as long as cysts are passed in the stool, sometimes for years. Treatment is with specific antiparasitic drugs.

Preventive measures require

1. sanitary disposal of human feces from patients;

2. proper surveillance and protection of public water systems to prevent fecal contamination (filtration of large water systems; iodine treatment or boiling of small water supplies);

3. education of food handlers and the general public in personal hygiene, particularly handwashing after defecation and before eating or preparing food;

4. control of fly populations with approved insecticides, sanitary disposal of garbage, and preventing access to food by screening;

5. soaking raw fruits and vegetables in approved disinfecting solutions before eating; and

6. indoctrinating known carriers concerning methods to prevent transmission, e.g., washing hands well after defecation.

Management of patients, contacts, and the nearby environment requires

1. isolation of patients with enteric precautions and exclusion of persons with symptoms from food handling or patient care duties;

2. proper disposal of patient feces; and

3. epidemiologic investigation for methods of transmission.

(Household members and other close contacts should have stool specimens checked for Entamoeba histolytica.) There are no requirements for quarantine or immunization.

In populations with a large percentage of carriers, a failure of sanitary facilities (e.g., sewage disposal or water treatment) or improper food handling techniques could result in large outbreaks.

Botulism

Botulism is a serious condition caused by poisoning from a bacteria-produced toxin. The clinical course includes the initial symptoms of drooping eyelids, blurred or double vision, sore throat, dry mouth, vomiting, and diarrhea, which may be followed by symmetrical paralysis. There is no fever unless accompanied by an infection. The agent is a toxin produced by Clostridium botulinum.

A diagnosis is made by identification of the toxin in the patient's stool or serum. The presence of the specific toxin in suspected food supports this diagnosis. Outbreaks of botulism occur worldwide and are usually traced to food preservation techniques, where the spores of Clostridium botulinum are not destroyed in the process. Cases almost never result from consumption of commercially processed foods.

The reservoir is the intestinal tract of animals and fish, soil, and marine sediment. Botulism is thus acquired by eating food containing the toxin of Clostridium botulinum. The incubation period averages about 24 hours. Botulism is not communicable from man to man. Treatment is primarily with an intravenous or intramuscular injection of trivalent botulinal antitoxin.

Preventive measures include

1. surveillance of commercial food processing plants to ensure proper processing and preparation;

2. never consuming or "taste testing" commercially prepared food in deformed containers or with "off-odors";

3. purchasing of food for the use of the Navy and Marine Corps from establishments listed in the Directory of Sanitarily Approved Food Establishments for Armed Forces Procurement; and

4. education of persons who can food at home concerning time, pressure, and temperature requirements to kill spores of Clostridium botulinum.

Management of patients, contacts, and the nearby environment includes

1. boiling or disinfecting food and utensils containing toxin with chlorine to destroy the toxin;

2. evaluation of contacts (those who have eaten food containing the toxin) by a medical officer; and

3. investigation of the most recent food consumed by patients affected and recovering suspected food for testing and proper disposal.

There is no requirement for quarantine.

If a single case is suspected, immediately consider a group outbreak which involves a family or other group who shared the common food. Home canned foods should be considered first. If it is determined that a commercial food product is involved, an immediate recall is indicated. NAVSUPPINST 10110.8 series outlines procedures to be taken by Navy and Marine Corps food service facilities.

Chickenpox-Herpes Zoster (Varicella-Shingles)

Chickenpox is an acute generalized viral disease with sudden onset, low grade fever, and mild constitutional symptoms. It begins with a maculopapular rash and rapidly progresses to characteristic vesicles that remain for 3 to 4 days and form scabs.

Usually more lesion appear on skin covered by clothing and in the hair than on uncovered skin. New lesions appear through the course of the disease; therefore, all stages of the lesions may be present at the same time. Occasionally adults develop severe constitutional symptoms and fever. Deaths are rare for both adults and children.

Herpes zoster is a later attack from the same infectious agent which may have remained latent in the body for many years. It is characterized by lesions similar to those of clinical chickenpox; however, they appear on the body in a distribution pattern supplied by sensory nerves or dorsal root ganglia. The lesions are usually unilateral, deeper, and more numerous than with chickenpox. Severe pain and a prickling, tingling or creeping sensation of the skin is common. Zoster occurs much more frequently in adults; however, some children are affected, especially those who experienced chickenpox prior to 2 years of age and those under treatment for cancer.

Diagnosis is usually established by clinical examination. Occurrence is worldwide. The infectious agent is the varicellazoster virus. Man is the reservoir.

Chickenpox is readily transmitted from man to man by direct contact, droplet and airborne respiratory secretions, fluid from vesicles (including cases of zoster) and freshly contaminated fomites. Contacts infected by zoster develop chickenpox. The incubation period is usually 2 to 3 weeks. The patient is communicable for 1 to 5 days prior to the onset of the rash and for about 6 days from the occurrence of vesicles. All persons not previously having the disease are susceptible. The first infection gives lifelong immunity. Treatment is symptomatic.

Preventive measures include

1. protecting high-risk individuals from exposure; and

2. administering Varicella-Zoster Immune Globulin to immunosuppressed patients which will modify or prevent the disease when given within 4 days of the exposure.

Management of patients, contacts, and the nearby environment requires

1. exclusion of children from school for 7 days after the appearance of the rash;

2. strict isolation when patients are hospitalized to protect susceptible immunocompromised patients;

3. concurrent disinfection of fomites soiled by discharges from the nose, throat, and lesions of patients; and

4. quarantine from 7 to 21 days after exposure could be justified to protect immunologically compromised patients in hospitals.

Epidemic measures are not necessary. However, when large numbers of children are crowded in conditions such as emergency housing, large outbreaks may occur.

Cholera

Cholera is an acute bacterial intestinal infection. Signs and symptoms are sudden and include vomiting, large quantities of watery stools, dehydration, and circulatory failure. In serious cases with no treatment, the mortality rate may be much greater than 50 percent and fatalities may occur within a few hours of the onset of illness. With proper medical care, the mortality rate can be very low.

Historically it is endemic in parts of Asia. In recent years, endemic areas have expanded to include Eastern Europe and Africa. Sporatic cases occur among U.S. travelers coming from all parts of the world.

The infectious agent is Vibrio cholerae. The reservoir is man. The major method of transmission is drinking water contaminated with excretions of patients. Other avenues are from contaminated food (including raw seafood from polluted water), and eating food prepared/served with unwashed hands. The average incubation period is 2 to 3 days. It is communicable during the period when the stool is positive for Vibrio cholerae; this period continues for a few days after recovery. Patients who develop into carriers may be communicable for several months.

The primary treatment is with the administration of large amounts of oral or intravenous fluids. Antibiotics given at the direction of a medical officer may be helpful in reducing the duration and severity of diarrhea and fluid loss.

Preventive measures for control of the disease include

1. proper disposal of human feces;

2. providing clean drinking water and water treatment and disinfection; and

3. emphasizing good personal hygiene, especially handwashing before eating and after using the latrine.

Management of patients, contacts, and the nearby environment requires

1. isolation of patients by enteric (gastrointestinal) precautions, e.g., handwashing and disposal of intestinal excretions;

2. observing contacts of patients for symptoms 5 days from the last exposure (antibiotic prophylaxis and immunization are not routinely recommended); and

3. conducting an investigation for the source of the infection.

There is no requirement for quarantine.

Epidemic control entails

1. providing clean potable water and sanitary sewage disposal;

2. identifying the location of the source of infection and appropriate control methods; and

3. ensuring sanitary food handling.

There are some international requirements. Ships and aircraft arriving from cholera areas must follow procedures outlined in International Health Regulations; details are found in SECNAVINST 6210.2. Except for a few specified countries, immunization is not required for international travel.

Dengue Fever (Breakbone fever)

Dengue fever is characterized by a sudden onset of fever (occasionally lasting 7 days or more), intense headache, pain behind the eyes, joint and muscle pain, and a rash. There is early redness of the skin in some patients; usually for 3 to 4 days after the beginning of fever, a rash presents with small discolored raised spots or closely aggregated bright red points. Minute hemorrhagic or purpuric spots may appear on the feet, legs, axillae, or palate at about the same time the temperature returns to normal. Patients with dark skin often have no visible rash.

The infectious agents are the viruses of dengue fever (types 1, 2, 3, and 4). These viruses also cause dengue hemorrhagic fever (discussed later). The reservoir is either man-mosquito or monkey- mosquito, depending on the geographic area. Dengue is endemic to tropical Asia, West Africa, parts of the Caribbean, and several countries in Central and South America.

The virus is transmitted to man by the bite of mosquitoes belonging to the genus Aedes. Mosquitoes acquire the virus by biting man and, in some areas, monkeys. The incubation period is usually 5 to 6 days. Patients are normally infective to mosquitoes 24 hours before the onset until the fifth day of the disease. Treatment is supportive; there are no specific antibiotics.

Preventive measures require

1. implementing mosquito surveys in affected communities to determine the density of vector mosquitoes, identifying breeding places, and eliminating the vectors where practical; and

2. making information available to the public concerning methods for protection from the vector mosquito bites such as the use of repellents, screening, and bed nets.

Management of patients, contacts, and the nearby environment includes

1. precautions with patient blood by denying mosquitoes access to the patient for at least 5 days after attack by using screens, an approved residual insecticide, or by the use of bed nets; and

2. investigation of a case including the place of residence at the time of infection (3 to 15 days prior to the onset) and search for unreported or undiagnosed cases.

There is no requirement for quarantine or immunization.

Epidemic measures, when necessary, include

1. surveying, locating, and eliminating all manmade Aedes mosquito breeding places;

2. encouraging all persons who are occupationally exposed to the vectors to use repellents; and

3. air dispersal of approved insecticides to stop epidemics.

International measures require strict enforcement of all existing international agreements designated to prevent the spread of this disease by man, monkey, and mosquitoes via ships, airplanes, and land transportation from endemic areas.

Dengue Hemorrhagic Fever

This severe illness affects primarily children, but cases can be seen in adults. Symptoms and signs include circulatory shock, high fever, loss of appetite, vomiting, headache, and abdominal pain. A hemorrhagic phenomenon is seen, which includes excessive bleeding at venipuncture sites, the nose, and gums. Tissue is easily bruised. In some patients, after a few days of fever, their condition deteriorates into sudden shock (known as the dengue shock syndrome) with blotchy cool skin, cyanosis around the mouth, rapid pulse, and abnormally low blood pressure. In untreated cases of the dengue shock syndrome, the fatality may be as high as 40 to 50 percent.

Outbreaks of dengue hemorrhagic fever have been reported throughout Southeast Asia and Cuba. The occurrence is during the wet season when the Aedes aegypti population is highest. About a third of all deaths are under 15 years of age. This disease primarily affects the indigenous population.

The infectious agent is the dengue virus (types 1, 2, 3, and 4). The reservoir is Aedes aegypti mosquito and man, and it is transmitted by a mosquito bite. The disease is believed to occur by an immunological reaction from a second or subsequent infection with the dengue virus. See the Dengue Fever section for method of control.

Giardiasis

Giardiasis is a parasitic infection of the small intestine. Symptoms may include chronic diarrhea, excess fat in the stools, abdominal cramps, bloating, frequent loose pale stools, fatigue, and weight loss. The diagnosis is established by identification of cysts or trophozoites in feces.

Giardiasis occurs worldwide and in children more often than in adults. More cases occur in areas with poor sanitation, in institutions, and in day-care centers. Waterborne outbreaks have been frequently seen in the United States.

The infectious agent is Giardia lamblia, a protozoa. Reservoirs include man, beavers, and other wild or domestic animals.

Local outbreaks occur when the cysts are ingested with contaminated water and less often in fecally contaminated food. Transmission may occur from person to person by the fecal-oral route in day-care centers.

The incubation period ranges from 5 to 25 days. Giardiasis is communicable during the period of infection; undiagnosed carrier states are common. Treat the infection as directed by a medical officer. Quinicrine hydrochloride (Atabrine) or metronidazole (Flagyl) are drugs of choice.

Preventive measures for control include

1. filtering of public water supplies suspected to be at risk from human or animal fecal contamination;

2. ensuring that families, inmates, and personnel concerned with institutions and day-care centers receive training in personal hygiene after defecttion; and

3. ensuring that emergency water supplies taken from suspected sources are boiled or treated with chlorine or iodine.

Management of patients, contacts, and the nearby environment include

1. enteric precautions for patients and

2. investigating contacts and the environment for the source of infections.

There is no requirement for quarantine.

Epidemic measures include investigating cases to determine a common source, such as water, food, or direct contact, and instituting measures to prevent transmission.

Viral Hepatitis

Several different illnesses are considered as viral hepatitis; they have similarities and differences. This section will discuss the two major types.

Viral Hepatitis A - The onset is gradual over several days with symptoms of fever, malaise, loss of appetite, nausea, abdominal discomfort, and, a few days later, jaundice. The course of this disease varies from the commonly seen mild form (lasting for 1 to 2 weeks) to the uncommonly seen severe form (lasting several months). A convalescence of several weeks can be expected. Complete recovery without sequelae can be expected. Many cases are mildly symptomatic with no jaundice. Viral hepatitis A occurs worldwide in epidemics and is endemic in many developing countries. Many outbreaks occur in institutions, housing areas, and in military forces. This disease is more common in schoolage children and young adults.

The infectious agent is the hepatitis A virus. The reservoir is man. The average incubation period is about 28 to 30 days, but it will range from 15 to 50 days, depending on the virus dosage received.

Transmission is from person to person by the fecal-oral route. Hepatitis A virus is at the highest levels in feces 1 to 2 weeks before the symptoms occur and decreases rapidly after the onset of jaundice. Many outbreaks are spread by food and water. Raw or under-cooked clams and oysters have been incriminated. Viral hepatitis A appears to be most communicable during the 2 weeks before the symptoms occur and is probably not transmitted after the first week of illness. There is no specific treatment, except for supportive measures.

Preventive measures includes

1. education of the public (especially food handlers and preparation personnel) concerning personal hygiene and good sanitation, e.g., good handwashing and sanitary disposal of human feces; and

2. stressing handwashing among the staff after each diaper change in child care centers.

If one or more cases occur, consider giving immune globulin to the staff, to other children who attend, and to the families of children attending.

Also, travelers to highly endemic areas who plan to remain for up to 3 months may be given human immune globulin in a dose of 0.2 to 0.4 ml/kg of body weight (or 2 ml total for adults). For continued long-term exposure, 0.6 ml/kg of body weight (5 ml total for adults) may be given; it should be given every 4 to 6 months while in the area. At this time a vaccine specifically against hepatitis A is not available for general use.

Management of patients, contacts, and nearby environment includes

1. isolation of patients with enteric precautions for the first 2 weeks of illness;

2. passive immunization with human immune globulin for usually only household and sexual contacts (intimate contacts); and<

3. investigation of contacts to include a search for missed cases, a search for a common source, and a surveillance of household or close contacts.

There are no requirements for quarantine.

When necessary during epidemics, several measures are required. An investigation should be conducted to determine the method of transmission and to identify the population at risk of infection. If viral hepatitis A is diagnosed in a food handler, give human immune globulin to other food handlers in the facility. However, it is recommended that patrons not be immunized unless an infected food handler prepared foods that were not cooked, his or her personal hygiene was deficient, and human immune globulin can be given within 2 weeks of exposure to the index case. If necessary, sanitary practices should be improved to prevent fecal contamination of food and water. Mass administration of human immune globulin should be considered to control outbreaks in institutions. Epidemics of hepatitis A may be expected during disaster situations where large numbers of people are crowded together with poor sanitation and inadequate water supplies. If cases occur, it is recommended that efforts be made to improve sanitation and water supplies. Administration of human immune globulin cannot be recommended as a substitute for proper environmental health measures. There is no requirement for international measures.

Viral Hepatitis B - The onset progresses gradually. There is loss of appetite, slight abdominal discomfort, nausea, vomiting, joint pain, rash, and jaundice. Fever, if present, is usually mild. The severity of this disease ranges from inapparent cases to death due to severe hepatic injury.

The diagnosis can be confirmed by demonstration of a specific blood virus particle, the hepatitis B surface antigen (HBsAg), or the recent development of antibody to core and/or surface antigens (anti-HBc, anti-HBs, respectively). HBsAg can be found in the serum for several weeks before the appearance of symptoms and for weeks to months after the onset and remains present in chronic infections. The infectious agent is the hepatitis B virus. Man is the only recognized reservoir.

Although HBsAg is found in numerous body secretions/excretions, only blood, saliva, semen, and vaginal fluids have proven to be infectious. Transmission occurs by percutaneous inoculation (such as a needle stick) with infective body fluids or by sexual exposure. Human blood, plasma, serum, and other blood products may transmit the hepatitis B virus. Thus all blood products are screened in the laboratory for HBsAg. Contaminated needles, syringes, and other intravenous equipment are frequently involved in transmission, especially among drug abusers. The infection is also rarely spread through open wound contamination by blood or sera from another infected individual. The agent may also be transmitted by heterosexual and homosexual contact. The shared use of personal items, e.g., razors, and toothbrushes, has been implicated as a rare cause.

The average incubation period is from 60 to 90 days. Blood is infective several weeks before the first symptoms appear, during the acute clinical disease, and, in those cases that develop into the chronic carrier state, it may be infectious for years. The is no specific treatment except for supportive measures.

There are several preventive measures. Inactivated vaccines are now commercially available against viral hepatitis B. The vaccine is recommended for those persons who may come into contact with blood, persons who receive repeated blood transfusions or blood fractions, household contacts of carriers, the sexually promiscuous, staff in institutions for the retarded, hemodialysis patients, and illicit injectable drug users. Pregnancy is not necessarily a contraindication for immunization.

Pregnant women in high risk groups should be tested for the presence of HBsAg and, if positive, their infants should receive postexposure prophylaxis (hepatitis B immune globulin and hepatitis B vaccine).

Strict testing discipline should be enforced in all blood banks. Donated blood should be tested for HBsAg. All donors should be rejected who have a history of viral hepatitis, present evidence of drug abuse, or received a blood transfusion or tattoo within the past 6 months. Unscreened blood or blood products are not administered to any patient unless an absolute emergency. Perform sterilization on all syringes, needles, acupuncture needles, and stylettes. The use of disposable equipment is recommended.

Management of patients, contacts, and nearby environment includes

1. isolation (inpatient and outpatient) with precautions for blood and body fluids until the disappearance of HBsAg and the appearance of anti-HBs;

2. concurrent disinfection for all equipment contaminated with blood, saliva, or semen; and

3. immunizing contacts with hepatitis B immune globulin, human immune globulin, or hepatitis B vaccine, as directed by a medical officer.

It is very important to administer prophylaxis as soon as possible after exposure. There is no requirement for quarantine.

If the occurrence of two or more cases can be related to a common exposure, search for more cases. Enforce strict aseptic techniques. If blood derivatives are implicated, recall the lot and trace all persons who received the product, in search of additional cases. No international measures are required for hepatitis B patients or their contacts.

Influenza

Influenza is an acute viral disease primarily involving the respiratory tract with symptoms of fever, chills, headache, muscular pain, exhaustion, acute rhinitis, sore throat, and cough. Recovery is usually complete within 2 to 7 days. During large epidemics acute illnesses and deaths may be expected among the elderly and other patients with chronic medical disorders. <> Influenza occurs worldwide as epidemics or localized outbreaks. Attack rates are about 15 to 25 percent in large communities and in isolated populations may be as high as 40 percent. The infectious agents are types A, B, and C influenza virus. Epidemics of type A occur in the United States approximately every 1 to 3 years; type B occurs every 3 to 4 years, with occasional mixed epidemics. Epidemics usually occur during the winter in temperate regions and in the tropics at any season of the year. The reservoir for the influenza is man.

Influenza is transmitted most commonly by the airborne route through infective droplets from coughing, sneezing, and close talking, especially in crowded populations. The incubation period is very short, approximately 1 to 3 days. The period of communicability is approximately 3 days, beginning with the first clinical symptoms.

An attack gives immunity only to the specific type or subtype of the virus involved. Vaccines provide immunity to a particular virus and related strains to which an individual has been previously exposed.

Current policy requires that all active duty Navy and Marine Corps personnel receive the annual influenza vaccine.

Management of patients, contacts, and the nearby environment includes the following principles: Because there is a usual delay in establishing the diagnosis, many others can become infected. Therefore, it is usually not practical to isolate cases. It may be desirable to isolate infants and younger children by keeping them in the same room. No concurrent disinfecting is required. No quarantine is required. Investigation of contacts is of no value and is not recommended.

At the beginning of epidemics, it is important that preventive medicine personnel establish surveillance of epidemics to determine the extent and progress that community functions are affected.

Malaria

Early symptoms of the four different types of human malarias are similar. Laboratory studies are necessary for differential diagnosis. Falciparum malaria is the most serious type and usually has various symptoms of fever, chills, sweating, headache, jaundice, blood coagulation defects, shock, renal failure, liver failure, and disorientation and delirium. Prompt diagnosis and treatment of all malarias is essential; however, falciparum malaria, because of its severity, should be considered a medical emergency.

The other three types of malarias are not life threatening for healthy adults; however, the very young, the aged, and individuals with other diseases may be at serious risk. General symptoms for these malarias include an indefinite period of malaise, which is followed by chills, shaking, fast rising temperature, usually headache, nausea, and sweating. Symptoms are followed by a time period with no fever and the cycle of chills, fever, and sweating is repeated each day, every other day, or every third day. If untreated, a primary attack continues from 1 week to more than a month.

The diagnosis can be established by the identification of malaria parasites in stained smears of patient blood on microscope slides (blood films). To find the parasites, it may be necessary to repeat the blood films.

Malaria occurs in many tropical and subtropical areas worldwide including Central and South America, Asia, and Africa.

The infectious agents for the human malarias are, Plasmodium vivax, P. falciparum, P. malariae, and P. ovale. Mixed infections frequently occur. Man is the reservoir for human malaria. Malaria is transmitted by the bite of the female Anopheles mosquito and by injection, blood transfusion, and contaminated needles and syringes.

The incubation period depends on the particular Plasmodium species, and it may range from days to months. Humans are infectious to mosquitoes as long as gametocytes are in their blood. The period of time that gametocytes are in the blood varies with the species, strain, and medication.

Preventive measures include

1. eliminating or reducing anopheline mosquito breeding places by draining or filling impounded water;

2. applying effective approved residual insecticide to surfaces where anopheline mosquitoes rest;

3. in endemic areas, spraying sleeping quarters with pyrethrum and/or using other approved insect repellents on exposed skin;

4. obtaining an accurate history of blood donors concerning malaria and possible malaria exposure before accepting blood;

5. locating and treating all acute and chronic cases of malaria that have occurred in the same area as the index case; and

6. practicing the regular use of chemosuppressive drugs in malarious areas.

Chloroquine is the most commonly used drug for this.

Patients should be isolated by blood precautions. However, no concurrent disinfection measures are required. No quarantine measures are required and immunization of contacts is not applicable.

An increase in malaria cases may be expected with wars, other social upheavals, and any climactic changes that increase breeding areas for vectors in endemic regions.

International measures are extremely important. Aircraft, ships, and other transportation vehicles going into and coming out of malarious and mosquito populated areas should be properly disinfected by health authorities. Finally, consider the use of antimalarial drugs when there is a mass movement of migrants from areas where malaria is endemic to malaria free areas.

Measles

Measles is an acute viral disease with signs and symptoms of fever, conjunctivitis, rhinitis, cough, and small irregular bright red spots with a bluish white center (Koplik's spots) located inside the mouth on the cheeks. A red blotchy rash characteristically begins on the face between the third and seventh day and then spreads to the trunk. Measles is most serious in adults and infants; otitis media, pneumonia, and encephalitis may occur as complications. In the United States and Canada, since the onset of childhood immunization programs, measles now occurs primarily in preschool children, adolescents, young adults, and those refusing vaccination. In temperate climates, most cases occur in late winter or early spring. In the tropics, most children acquire measles at an early age as soon as the maternal antibody lowers.

The infectious agent is the measles virus. Man is the reservoir. Measles is spread by nasal or throat secretions through droplets, direct contact, and less frequently by airborne methods or fomites. The incubation period averages about 10 days from exposure until the onset of fever and may vary from 8 to 13 days. The rash usually appears 14 days after exposure. Measles is communicable from just prior to the onset of fever to about 4 days after the appearance of the rash.

Susceptibility is general except for those persons who have recovered from the disease or those who have been immunized. Recovery usually gives permanent immunity. Infants whose mothers are immune are usually immune for the first 6 to 9 months of their lives.

There is no specific treatment for measles.

The primary preventive measure is vaccination with the live attenuated measles vaccine. It is recommended for all individuals susceptible to measles.

For patient management, isolation is not practical for an entire community; however, it is recommended that children be kept home from school until at least 4 days after the appearance of the rash. For hospitalized patients, practice respiratory isolation from the onset of fever until after the fourth day of rash to reduce exposure of other high risk patients.

During epidemics, the spread of measles can be limited with immunization programs to protect susceptible individuals. Measles may have a high fatality rate in underdeveloped populations, therefore, vaccines, if available, should be given early in an epidemic to limit the spread. If there is a shortage of vaccines, give young children the highest priority.

Meningococcal Meningitis

Meningococcal meningitis is a bacterial disease that has a sudden onset with symptoms of fever, severe headache, nausea and usually vomiting, stiff neck, and often a pinpoint red rash. Coma and delirium occur frequently. Occasional cases experience purplish patches caused by extravasation of blood into the skin, and shock at the onset of illness. It can be fatal without treatment. The diagnosis is established by the identification of bacterial organisms in a gram stain of spinal fluid or blood.

Meningococcal meningitis occurs in both tropical and temperate areas. Sporatic cases usually occur throughout the year in urban and rural areas with the greatest numbers occurring during the winter and spring. Epidemics may occur at irregular intervals. This is usually a disease of small children, but it can occur in young adults. In adults, it is more common in those recently introduced to crowded living conditions.

The infectious agent is the bacterium Neisseria meningitidis. The reservoir is man. Transmission is by direct contact, which includes droplets and discharges from the nose and throat of infected persons or asymptomatic carriers. About 25 percent of a population may be carriers with no actual disease cases. In military units during outbreaks, more than one-half of the unit may be asymptomatic carriers. The incubation period is normally for 3 to 4 days. Meningococcal meningitis is communicable as long as the organism is present in discharges from the nose and mouth.

Penicillin in adequate doses given parenterally remains the drug of choice.

Preventive measures are primarily based on the immunization of personnel who live in crowded conditions, e.g., military recruits.

For patients, respiratory isolation is required until 24 hours after chemotherapy is begun. There should be surveillance of household or other intimate contacts for early symptoms of meningitis, especially fever, so that early treatment can be started. Household or other intimate contacts may benefit from oral chemotherapy. Routine cultures of contacts are not recommended because the results are not sensitive enough and are not completed promptly enough to effect the decision to give prophylaxis.

During community outbreaks, emphasis is placed on surveillance, early diagnosis, and treatment.

Mumps

Mumps is a viral disease with symptoms of fever, swelling, and tenderness of one or more of the salivary glands (usually the parotid gland(s)). Fifteen to 20 percent of adult males experience infection of the testicle. About 5 percent of females experience ovary infections; however, reproductive sterility is a rare sequela. Aseptic meningitis occurs frequently as a symptom of central nervous involvement. Females during the first trimester of pregnancy may experience an increase in the rate of spontaneous abortions. Deaths are rare.

The infectious agent is the mumps virus. The reservoir is man. Mumps is transmitted by direct contact with saliva or by droplet spread with saliva from an infected person. The incubation period is about 18 days. Mumps are most infectious about 38 hours prior to the onset of illness and probably communicable from 6 days prior to swelling and tenderness of the salivary glands until 9 days later. Asymptomatic cases may be communicable. Susceptibility is general. After a clinical case or asymptomatic infection, immunity is generally lifelong.

There is no specific treatment.

Preventive measures are based on a vaccine available as a single vaccine or combined with rubella and measles.

Patients isolated should be using respiratory precautions in a private room for 9 days after the onset of swelling and tenderness of salivary glands or until the swelling has subsided.

Pediculosis

Pediculosis is an infestation of lice on the body and/or clothing. Lice and eggs (nits) are usually found in body hair or the inside seams of clothing. An infestation results in extreme itching and abraded skin (from bites and scratching). Secondary skin infections and inflammation of the regional lymph nodes may occur. Crab lice normally infest the pubic area. However, they may infest other hairy areas, including facial hair and eyebrows. Pediculosis occurs worldwide. Outbreaks are most common among children in schools or other institutions.

The infesting agents of pediculosis are Phthirus pubis (the crab louse), Pediculosis humanus capitis (the head louse), and P. humanus corporis (the body louse). The reservoir is man. Head and body lice are most commonly transmitted by direct contact with an infested person. Body lice and less frequently head lice are also transmitted by indirect contact with the personal belongings of an infested person, e.g., clothing and headgear. Crab lice are most frequently transmitted through sexual contact.

Lice are heat sensitive organisms and will leave a host with fever. Transmission easily occurs from person to person under crowded conditions. With ideal conditions lice eggs hatch in 7 days and reach sexual maturity in 8 to 10 days. Pediculosis is communicable as long as lice or eggs remain on an infected person or clothing.

Lice may be treated with 1 percent gamma benzene hexachloride lotions (Lindane, Kwell). (It should not be used on infants, young children, or pregnant or lactating women.) Normally a second application 7 to 10 days later is recommended to treat any eggs that survived. Clothing and bedding may be disinfected by washing in hot water.

Plague

Plague is a disease of animals and man (zoonosis) that is transmitted by a flea bite from infected rodents to susceptible animals, including man. The first sign is usually an inflammation of lymph nodes (bubonic plague) in the inguinal, axillary, or cervical regions, depending on the location of the flea bite. Lymph nodes may form pus, and fever develops. Septicemia may develop and carry the disease to other organs or systems, including the membranes covering the brain. When the lungs are affected (pneumonic plague), the disease may be transmitted from man to man by direct respiratory contact (coughing, spitting) or direct projection and may result in outbreaks or epidemics. The fatality rate for bubonic plague may reach 50 percent. Without treatment, septicemic plague and pneumonic plague are usually fatal. The fatality rate of all types of plague may be reduced with prompt diagnosis and medical treatment.

Diagnosis may be established by observing plague organisms in gram stains and cultures of material from a bubo, sputum, or spinal fluid.

The natural reservoir of plague is wild rodents, which can be in contact (and transmit their fleas) with domestic rats. Wild rodent plague has been found in many countries including those of North America, South America, the Middle East, Africa, Southeast Asia and Europe. In all areas of wild rodent plague, human plague can and does occur.

The infectious agent is Yersinia pestis. The reservoir is usually wild rodents, possibly rabbits, and larger carnivores. The incubation period is from 1 to 6 days.

With favorable weather, infected fleas may be communicable for several months. Pneumonic plague is easily transmitted from man to man under crowded conditions when susceptible persons are in close contact with cases. Persons who have recovered from plague may acquire the disease again with an additional exposure. Treatment with early antibiotic therapy (preferable within 8 hours and not later than 24 hours from the onset) is effective for pneumonic plague. There may be secondary infection. Bubos may require incision and drainage.

Preventing flea bites on humans and avoiding exposure of susceptible persons to pneumonic plague cases are the primary methods of control. Specific measures include

1. in endemic areas, establishing information programs to educate the public about infected rodents/fleas;

2. routine surveys of domestic and wild rodent populations to evaluate environmental control programs (e.g., poisoning and trapping programs) and the possibility of plague transmission from rodents to man; and

3. rodent and flea control in and around port facilities requiring additional steps, including the prevention of rat movement to and from ships (rat guards) and shipboard poisoning and fumigation.

Management of patients, contacts, and the nearby environment includes

1. disinfection and isolation of patient clothing and baggage;

2. ensuring that all persons exposed to pneumonic plague be isolated and placed on chemoprophylaxis with close surveillance for 7 days;

3. disinfestation of all contacts with bubonic plague patients and chemoprophylaxis for household contacts;

4. attempt to find all close contacts (e.g., household contacts and face-to-face contacts) exposed to pneumonic plague, as well as dead or dying rodents and their fleas; and (

5. vaccination for persons living in high plague areas, laboratory workers, and field workers.

International measures stipulate that ships and aircraft arriving from plague areas must follow procedures outlined in International Health Regulations. They must be rodent free or routinely deratted. Routine vaccination for plague is not required for international travel to almost all countries.

Poliomyelitis, Acute

Poliomyelitis (polio) is a serious viral disease with symptoms that may include fever, malaise, headache, vomiting, severe pain in muscles and spasms, stiff neck and back, and the paralysis that is characteristic of the disease. The virus multiplies in the alimentary tract and may then invade the central nervous system/spinal cord. Inapparent infections and minor illness probably exceeds paralytic cases by more than a hundred-to-one when the infection occurs in the very young.

The infectious agent is the poliovirus types 1, 2, and 3. The reservoir is man. Poliomyelitis is characteristically transmitted by fecal-oral or pharyngeal modes. The incubation period for paralytic cases is 7 to 14 days. The period of communicability is not known. Probably cases are most infectious during the first few days before and after the onset of symptoms.

There is no specific treatment. Expert care is required during acute illness for patients who need respiratory assistance secondary to paralyzed muscles for breathing.

The two important preventive measures include

1. effective vaccines (inactivated and live virus) that are available and beneficial; and

2. education of the local public concerning the advantages of immunization and on the methods of spread when a case is diagnosed.

For hospitalized cases, enteric precautions are needed. The investigation of contacts is limited to a search for sick persons, especially children, to provide proper care to unrecognized and unreported cases.

Trivalent vaccines should be put into use at the earliest indication of an outbreak in a local population.

International travelers should be adequately immunized prior to visiting endemic areas, usually third world countries.

Rabies

Rabies is an acute viral disease of the central nervous system that is essentially 100 percent fatal. Symptoms include a sense of apprehension at the onset, malaise, fever, headache, and sensory changes referred to the site of the animal bite wound. Symptoms progress to paralysis or paresis, spasms to the muscles of swallowing resulting in a fear of water (hydrophobia), and convulsions follow. The usual duration is 2 to 6 days; death often is due to respiratory paralysis.

The infectious agent is the rabies virus.

Rabies occurs worldwide and the reservoir, depending upon the country, is wild and domestic animals, including dogs, cats, skunks, raccoons, and some bats. Almost all mammals are susceptible to rabies.

Rabies is contracted by the introduction of virus-containing saliva of a rabid animal through a break in the skin, usually a bite. The incubation period in humans may range from 10 days to a year but is usually from 2 to 8 weeks.

The specific treatment for clinical rabies is intensive supportive medical care.

Preventive community measures rely heavily upon the licensing of dogs and cats with the documentation of antirabies vaccine receipt a requirement. Collect and destroy ownerless animals. Pet owners should be educated concerning necessary restrictions for dogs and cats, e.g., leashing or confining to owner's premises, or that strange-acting and sick animals of any species may be dangerous and should never be picked up or handled. Dogs and cats that have bitten a person or show signs of rabies should be detained 10 days for clinical observation. Wild animals and strays should be sacrificed immediately and the brain examined for evidence of rabies. Veterinary personnel should submit intact heads packed on ice (not frozen) of sacrificed animals or animals that die of suspected rabies to the cognizant laboratory for testing.

Individuals at occupational or operational high risk of wild/domestic animal bites should receive preexposure immunization with the antirabies vaccine. The prevention of rabies after an animal bite is based on physical removal of the virus by proper management of the bite wound and by specific immunization protection.

Rubella (German measles) and Congenital Rubella (Congenital Rubella Syndrome)

Rubella is a mild viral infectious disease. One to 5 days prior to the appearance of a rash, mild symptoms of malaise, loss of appetite, conjunctivitis, headache, low grade fever, and minimal respiratory symptoms may occur. The rash consists of a pink eruption, which begins on the face and spreads downward over the trunk and extremities. About one-half of the infections occur without an obvious rash.

Congenital rubella causes defects of the developing fetus of pregnant women with rubella. Approximately 25 percent of infants born to women with rubella during the first trimester of pregnancy are affected.

Rubella occurs worldwide and is endemic almost everywhere except in remote isolated communities. This disease occurs most often in the winter and spring. It is a disease of childhood in unvaccinated populations and of adolescents and adults in populations where children are immunized.

The infectious agent is the rubella virus. The reservoir is man. Rubella is transmitted when susceptible persons contact nasopharyngeal discharges from infected persons. When susceptible persons live under crowded conditions, e.g., military recruits, all susceptible unimmunized persons will probably be infected if the virus is introduced.

The average incubation period is about 18 days. Rubella is communicable from about a week prior to the appearance of a rash until about 4 days after the appearance.

There is no specific medical treatment for rubella.

Preventive measures are primarily concerned with the immunization of susceptible persons. Immunization with one dose of live attenuated rubella virus vaccine produces a long-lasting immunity in about 95 percent of all susceptible persons. It is recommended that all children receive a vaccine of combined rubella/measles at about 15 months of age. Emphasis should also be placed on immunizing susceptible adolescent and adult females, because rubella continues to occur in women of childbearing age. However, pregnant women should not be vaccinated.

In hospitals or institutions, when a patient is suspected of having rubella, isolation in a private room is recommended. Every attempt should be made to prevent exposing nonimmune pregnant women to rubella. Children should be kept home from school and adults should not go to work for 7 days after the onset of a rash.

Sexually Transmitted Diseases

Sexually transmitted diseases (STDs) are among the most common communicable diseases. Because of embarrassment or lack of education, a great many cases go unreported and untreated. Changes in sexual behavior, and the fact that many people are asymptomatic carriers, have added to the problems of control.

A hospital corpsman will have the responsibility of recognizing cases of sexually transmitted disease in the sickcall environment, initiating laboratory procedures to confirm the diagnosis, and educating personnel in recognizing the signs of sexually transmitted disease and the best way to avoid infection.

This section will deal with the most common types of sexually transmitted diseases: gonorrhea, nongonnococcal urethritis, syphilis, and genital herpes. There are many other less common sexually transmitted diseases that are not covered here. Current medical journals and books are a good source of information, in addition to current Naval texts and Instructions.

Each STD case should be interviewed by a contact interviewer trained by preventive medicine personnel. Information gained from the interviewer should be recorded on the Venereal Disease Epidemiologic Report Form, CDC Form 9.2936A, and be forwarded to the appropriate agency. The Interviewer's Aidfor VD Contact Investigation, NAVMED P-5036, contains guidance for conducting interviews. NAVMEDCOMNOTE 6222 series contains specific treatment re- quirements for sexually transmitted diseases.

Chlamydial Genital Infections

This infection causes urethritis in males and cervicitis in females. Clinically, in males the urethritis produces an opaque discharge of scanty or moderate quantity and urethral burning or itching on urination. Asymptomatic infections occur in 1 to 10 percent of sexually active men. In females, clinical symptoms similar to gonorrhea include inflammation and infection of the uterine cervix. Complications are infections of tube/ ovaries with risk of infertility. Diagnosis of nongonnococcal urethritis or cervicitis is usually based on the failure to demonstrate Neisseria gonorrhoeae on culture.

The infectious agent is Chlamidia trachomatis. The reservoir is man. The incubation period is 5 to 10 days or longer. Chlamydial genital infections are transmitted through sexual contact. The period of communicability is unknown. The specific treatment is tetracycline, doxycycline, or erythromycin, as directed by medical officer.

Preventive measures concerning health and sex education for this infection are the same for all sexually transmitted diseases. Emphasis should be placed on the use of condoms for promiscuous sexual contacts.

Investigation of contacts includes as a minimum the prophylactic treatment of regular sexual contacts; treatment of all sexual contacts, whether or not symptomatic, is recommended.

Gonococcal Infection of the Genitourinary Tract

The symptoms, severity, and ease of recognition of the bacterial disease gonorrhea are different in males and females.

For urethral infections in males, 2 to 7 days after an infecting exposure, a purulent discharge appears from the anterior urethra with burning upon urination. The infection may spread to the posterior urethra and produce epididymitis, or it may be limited to the anterior urethra. Asymptomatic carriage may occur. Rectal infections may be asymptomatic or may cause itching, painful spasms with a desire to evacuate the bowel, and an anal discharge. Rectal infection is common in male homosexuals.

In females, an initial urethritis or cervicitis, so mild it may pass unnoticed, occurs a few days after an infecting exposure. There is a risk of infertility from infection of the tubes and ovaries.

In both males and females, pharyngeal and anal infections are due to direct sexual contact. Conjunctivitis in adults is rare. Deaths may occur with endocarditis. Arthritis from systemic spread may cause permanent joint damage if antibiotic therapy is delayed.

The infectious agent is the bacterium Neisseria gonorrhoeae. Man is the only reservoir. The incubation period normally ranges from 2 to 7 days. The period of communicability may range from days to months in untreated cases, especially in asymptomatic individuals. Effective antibiotic therapy normally stops communicability in 24 to 48 hours.

Specific treatment for gonorrhea is under the supervision of a medical officer and includes various combinations of procaine penicillin G, ampicillin, amoxicillin, and tetracycline. Penicillinase-producing Neisseria gonorrhoeae (PPNG) and chromosomally mediated penicillin- resistant (B-lactamasenegative) are new forms of gonorrhea that are resistant to penicillin; these are usually treated with spectinomycin or cephalosporin derivatives.

Preventive measures are important. They include

1. providing general health and sex education to military personnel;

2. encouraging comprehensive diagnostic and treatment protocols; and

3. establishing case-finding programs, including interviews of patients and tracing of contacts.

Management of patients, contacts, and the nearby environment includes several principles. No isolation is required. Patients should avoid sexual contact until post-treatment cultures are negative for gonococci. Avoid previous untreated sexual partners to prevent reinfection. Investigation of contacts should include interviews of patients and location and treatment of contacts. Trained interviewers should be used when possible, especially with uncooperative patients. Immunization is not available.

Herpes Simplex

Two etiologic agents, herpes simplex virus (HSV) types 1 and 2, usually produce distinct clinical symptoms, depending on the portal of entry. HSV type 2 usually produces genital herpes; HSV type 2 principally occurs in adults and is sexually transmitted. In women, the most common sites of the primary lesions are the cervix and vulva; recurrent disease usually involves the vulva, perineal skin, legs, and buttocks. In men, lesions affect the penis or pubic areas and, in male homosexuals, the anus and rectum. Other genital or perineal sites and the mouth may be involved. Vaginal delivery of pregnant women with an active genital herpes infection gives a great risk of serious infection to the newborn. HSV type 2 infection in adult women is a possible risk factor associated with cervical cancer.

Herpes simplex occurs worldwide. HSV type 2 infection usually begins with sexual activity and is rare before adolescence.

The reservoir is man. The incubation period is from 2 to 12 days. The transmission of HSV type 2 to nonimmune adults is usually through sexual contact. Primary genital lesions are infective for 7 to 12 days. Each recurrent disease is infective from 4 to 7 days. Episodic reactivation of genital herpes occurs repeatedly in the great majority of patients for many subsequent years. Specific treatment for genital herpes is with the new topical and oral drug Acyclovir; this should be prescribed only by a medical officer.

Preventive measures include

1. the education of personnel on appropriate sexual hygiene practices;

2. encouraging the use of a condom in random sexual practice, to decrease the risk of infection when the health of the sex partner is unknown; and

3. the wearing of gloves by health care personnel who examine potentially infectious lesions.

Syphilis

Syphilis is a treponemal disease that may be acute, or chronic. Symptoms appear in stages as the untreated disease progresses through primary lesion, a rash of the skin and mucous membranes, a long period of latency, and finally lesions of the cardiovascular system, central nervous system, viscera, bone, and skin. The first symptom, a papule, appears within 3 weeks at the site of the direct exposure contact and often erodes to form an indurated painless ulcer (chancre). This is primary syphilis. After 4 to 6 weeks the chancre heals and the rash appears. This rash is flat, reddish, and patchy, affects the trunk and extremities, but characteristically is seen on the palms and soles. This rash typifies secondary syphilis. Within a few weeks or up to 12 months, the rash disappears and is followed by a latency period that may last from weeks to several years. Sometimes latency continues through life and recovery may occur. In many instances, after 5 to 20 years of untreated disease, lesions of tertiary syphilis can invade and destroy tissue in the skin, bone, central nervous system, heart and aorta.

The diagnosis for primary and secondary syphilis is confirmed by a darkfield microscopic examination of material from genital lesions or aspirates from lymph nodes, as well as the serologic test for syphilis in blood or cerebrospinal fluid.

The infectious agent is Treponemapallidum, a spirochete. The reservoir is man. The incubation period is usually 3 weeks and ranges from 10 days to 10 weeks. Transmission is by direct contact with exudates of moist lesions or body fluid secretions from mucosal surfaces (e.g., vagina, rectum, or pharynx) of infected persons during sexual contact. It can also be transmitted by kissing or fondling involving infected surfaces/lesions. Transmission can also occur through blood transfusion. Fetal infection can occur through placental transfer. The period of communicability is variable and inde