c. Typhus Fever. There are two types of typhus fever--endemic, transmitted to
man by the rat flea, and epidemic, transmitted by the body louse. Endemic typhus is
prevented in the same manner as plague--by eradicating the reservoir (the rat) and
protecting against the vehicle (the flea) by the use of insecticides. Epidemic typhus is
prevented by immunizing troops entering typhus areas and by protecting against louse
infestations by personal hygiene measures and the use of issued insecticide powder.
d. Miscellaneous Diseases.
(1) Numerous other diseases of lesser importance--not because they are
not seriously disabling, but because of a lower incidence--include the following:
(a) Schistosomiasis, caused by invasion of the bloodstream by a
parasitic blood fluke, is a hazard in Africa, South America, the Caribbean, and the
Orient. Larvae of the fluke can penetrate the skin of persons wading, swimming, or
working in infested waters. The only means of prevention is avoiding infested waters.
(b) Rocky Mountain spotted fever, spread by the bite of certain ticks, is
found in wooded and brushy areas of the United States, Canada, Mexico, Panama,
Colombia, and Brazil.
(c) Scrub typhus, a disease occurring in eastern and southeastern
Asia, northern Australia and adjacent islands, and India, is transmitted by the bite of
mites living in vegetation.
(2) Preventive measures for these diseases include avoiding infested areas,
where known and possible, use of individual insect repellent, and spraying campsites
before occupying them. Over 75 known viruses transmitted by mosquitos, ticks, and
flies have been implicated in causing encephalitides and fevers in man. Individual and
unit preventive measures consist of eliminating mosquito and fly breeding places, use of
protective netting, and the use of insecticides and repellents.
FOOD AND WATERBORNE DISEASES
Because of the difficulty of preserving the sanitary quality of food, water, and
utensils in the field, food and waterborne diseases constitute an ever-present hazard in
combat or field operations.
a. Foodborne Diseases. Foodborne diseases may be classified as foodborne
intoxication, chemical intoxication, and foodborne infections.
(1) Foodborne intoxication is caused by enterotoxins produced by certain
microorganisms, of which staphylococci are the most important. Preventive measures
include strict sanitation, exclusion from food service activities of all persons having
staphylococcal infections, and prompt serving of foods at proper temperatures to
preclude the growth of bacteria and the production of toxins. Botulism, another form of