from sewage-contaminated water, raw fruits and
vegetables, and contaminated milk and milk pro-
ducts are important vehicles in some areas of the
Typhoid fever is communicable as long as
typhoid bacilli remain in the feces or urine. Many
patients not appropriately treated become perma-
Specific antibiotics are the treatment of choice.
Preventive measures include (1) in field situa-
tions, providing for the sanitary disposal of
and adequate handwashing
facilities; (2) ensuring that fly proof latrines are
away from and downstream from the source of
drinking water; (3) controlling fly populations by
screening, with insecticides, and by the proper col-
lection and disposal of garbage to prevent
(4) requiring proper food
preparation and handling and proper refrigera-
tion; (5) at foreign ports, limiting the acquisition
of shellfish to supplies from approved sources;
(6) instructing patients, convalescents, and car-
riers concerning food personal hygiene; (7) ex-
cluding carriers and infected persons from food
handling. Immunization for the general popula-
tion in the United States is not recommended. Im-
munization boosters are required for many Navy
and Marine Corps personnel and recommended
for travelers to endemic areas.
For patients, isolation includes enteric precau-
tions while they are ill. Cases should not be
released from medical supervision until three con-
secutive cultures of feces taken at 1 month inter-
vals after the onset and 24 hours apart are
negative. If any one of these cultures is positive,
repeat at intervals of 1 month until three negative
cultures are obtained. Do not assign household
contacts to food handling until two feces cultures
taken 24 hours apart are negative.
The probable or actual source of every case
should be determined by searching for unreported
cases, carriers, and contaminated food, water,
milk, or shellfish.
Epidemic measures include (1) searching for
cases, carriers, or contaminated food or water that
may be transmitting the infections; (2) the exclu-
sion of suspected food; and (3) disinfecting all
suspected water with chlorine or iodine, or boil-
ing it before use.
During natural disaster situations, the
transmission of typhoid fever may be expected
with the disruption of food and water supplies and
excreta disposal in a displaced population if cases
or carriers are present. Vaccination of such
populations is not generally recommended; efforts
to provide safe food, water, and excreta disposal
are more effective.
Typhus Fever, Epidemic Louse-Borne
Typhus is caused by rickettsial agents, similar
to bacteria. The onset is frequently sudden and
commences with general pain, fever, chills,
headache, and prostration. After 5 to 6 days, a
macular red rash becomes apparent on the upper
trunk and then covers all the body, usually with
the exception of the soles, palms, and face. Tox-
emia is normally present. After about 2 weeks of
fever, typhus ends with rapid recovery. Without
specific treatment, the fatality rate is 10 to 40 per-
cent and increases in older persons. Cases may
be mild with an absence of rash, particularly in
children and persons partially protected by a
previous immunization. In the Brill-Zinsser
Disease, typhus recurs (without another exposure)
many years after recovery from the first infection.
The Brill-Zinsser disease is less serious with milder
symptoms and has a lower fatality rate.
Diagnosis may be established by serological
In the past, outbreaks of typhus often accom-
panied famine and war. Typhus is endemic in the
mountainous areas of Central and South America,
central Africa, and many countries in Asia. In the
United States, the infectious agent causes a disease
in flying squirrels, which may be passed to man
by their fleas.
The infectious agent is Rickettsia prowazekii.
The reservoir is man. Typically, the body louse
is infected when it feeds on the blood of a person
with typhus fever. Man is infected by crushing and
rubbing an infected louse or its feces into the bite
wound or other break in the skin. Some cases may
result from inhalation of dried airborne flea feces.
The incubation period averages about 12 days.
Treatment is with antibiotics.
Methods of control include control of lice with
insecticide dusts, washing clothes and bathing,
and immunization of susceptible persons at high
risk, e.g., local military and labor forces and
Management of patients, contacts, and the
nearby environment includes ( 1 ) no requirement
for isolation after delousing patients, contacts,
clothing, and quarters; (2) concurrent disinfection
of patients, contacts, bedding, and clothing with
approved insecticides; (3) quarantine for 15 days
for susceptible louse-infected persons exposed to
typhus; and (4) surveillance of immediate contacts
for 2 weeks.