The epidemic potential is serious in louse-
infested populations. Epidemics may be expected
in wars, famines, and other conditions, where
people are overcrowded and malnourished. Poor
personal hygiene encourages pediculosis. During
epidemics, all contacts and perhaps the entire
community should be deloused with a residual in-
secticide. Administer the vaccine to susceptible
persons, if directed.
Immunization is not required for international
An attack of yellow fever usually results in
abrupt signs and symptoms of fever, headache,
backache, nausea, vomiting and prostration.
Later in the course of the disease, the heart rate
slows and becomes weaker, and there is a de-
creased output of urine. Bleeding may occur from
the nose, mouth, and stomach. The stools become
dark colored and tarry due to the presence of
blood. Jaundice is mild early in the disease and
becomes pronounced later. The mortality rate
may be very high.
Urban yellow fever (transmitted by the Aedes
aegypti mosquito) has not occurred in the
Americas since 1954. However, outbreaks of ur-
ban yellow fever are now reported from other
countries/continents. Jungle yellow fever is found
in several African countries and in Central and
The infectious agent is the yellow fever virus.
Man and the Aedes aegypti mosquito are the
reservoirs for urban yellow fever. The reservoirs
for jungle fever are monkeys, marsupials, and
forest mosquitoes. Man acquires the disease when
bitten by an infected mosquito. The incubation
period is from 3 to 6 days. Patients with yellow
fever are infective from just prior to the onset of
fever through the first 3 to 5 days of the illness.
When infected, mosquitoes remain so for life.
There is no treatment other than supportive
Preventive measures against urban yellow
fever are primarily through eradication of the
Aedes aegypti mosquitoes. Vaccination for hu-
mans is also indicated. Jungle yellow fever can
be controlled best by immunizing all persons who
work or visit endemic areas. Any person who
enters these areas should use protective clothing,
repellents, and bed nets.
Management of patients, contacts, and the
nearby environment includes patient blood isola-
tion precautions. In rural areas, deny mosquitoes
access to patients for at least 5 days after the onset
by screening, spraying with residual insecticides,
and using bed nets. Insecticides should be applied
in all houses in the area.
As part of the investigation, question the pa-
tient about all places visited 3 to 6 days prior to
the onset to determine where yellow fever was ac-
quired (focus), and place all persons visiting the
focus under surveillance. Survey suspected areas
for mosquitoes that transmit the disease and
eradicate them with approved insecticides, if pos-
sible. Investigate deaths and mild illnesses with
fever in the area to determine if yellow fever was
International measures require that ships, air-
craft, and land transportation arriving from areas
where yellow fever is endemic will follow regula-
tion outlined in International Health Regulations.
Many countries require a valid international certi-
ficate of yellow fever vaccination when traveling
through or from yellow fever areas. The certificate
is valid from 10 days after vaccination through
the next 10 years.
HEALTHFUL LIVING ASHORE
As a Medical Department representative, you
will often be called upon to help ensure that all
hands have healthful living conditions, both
ashore and afloat. This manual gives only a rough
outline of your responsibilities. To perform ade-
quately in this area, you must become familiar
with the BUMED/NAVMEDCOM Instructions
in the 6200 series, the Manual of Naval Preventive
Medicine (NAVMED P-5010), and other appli-
cable manuals and publications that may be
referenced or become available to you.
Foodborne illnesses are an ever-present danger
in the military environment. They pose a real
threat to the health and morale of our personnel.
To prevent their occurrence, one must ensure that
all foods are procured from approved sources and
processed, prepared, and served with careful
adherence to recommended sanitary practices.
The majority of foodborne illnesses can be traced
to food that has been prepared too far in advance;
temperature and time factors; or food service per-
sonnel who ignored or are inadequately trained
in food handling techniques. These points need to