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 administra-
tion 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 treat-
ment 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 pa-
tients by enteric (gastrointestinal) precautions,
e.g., handwashing and disposal of intestinal ex-
cretions; (2) observing contacts of patients for
symptoms 5 days from the last exposure (an-
tibiotic 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 in-
fection 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
details are found in
SECNAVINST 6210.2. Except for a few specified
countries, immunization is not required for inter-
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. Mos-
quitoes acquire the virus by biting man and, in
some areas, monkeys. The incubation period is
usually 5 to 6 days. Patients are normally infec-
tive to mosquitoes 24 hours before the onset until
the fifth day of the disease. Treatment is suppor-
tive; there are no specific antibiotics.
Preventive measures require (1) implementing
mosquito surveys in affected communities to
determine the density of vector mosquitoes, iden-
tifying breeding places, and eliminating the vec-
tors 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 in-
fection (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) en-
couraging all persons who are occupationally
exposed to the vectors to use repellents; and
(3) air dispersal of approved insecticides to stop
International measures require strict enforce-
ment 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
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