Signs/symptoms. The onset of the disease is characterized by
abdominal pain, followed by diarrhea, and sometimes by nausea and vomiting. The
disease is usually a mild, self-limiting disease lasting from 2 to 24 hours.
Treatment. The only treatment required is supportive care.
Reservoir. The reservoirs of the disease are man, cattle, pigs, and
Source of infection. Food contaminated with infected feces is the
immediate source of infection. Foods containing meat--usually meat pies, stews, and
reheated meats--are those most commonly associated with outbreaks.
Typhoid fever is a systemic infection.
a. Signs/Symptoms. Clinical signs include a continued fever, enlargement of
the spleen, and rose spots on the body trunk. Constipation is more common than
diarrhea, but either may occur. Antibiotic therapy has reduced the case fatality rate to
b. Incubation Period/Cause. The incubation period usually ranges from 1 to 3
weeks, with 2 weeks the usual. The causative agent, Salmonella typhi (there are at
least 50 types), is discharged in the feces or urine of infected persons, including healthy
c. Transmission. Typhoid is transmitted by ingestion of shellfish taken from
sewage-contaminated beds, raw fruits and vegetables fertilized by night soil, and
contaminated milk and milk products. The disease is widespread throughout the world
and is especially prevalent in wartime or during floods.
During such periods, typhoid carriers in the general population are more
likely to become food handlers and sewage is more likely to become mixed with water
used for drinking by humans.
Despite routine administration of triple vaccine to United States Army
troops, more than 500 became typhoid fever cases during World War II.
Flies sometimes are mechanical vectors.
d. Reservoir. Typhoid bacilli multiply rapidly in milk and other food and may
survive several weeks in cheese and butter, 7 days in well water, and throughout the
winter in frozen soil. They are killed, however, when subjected to a temperature of 60
C (140 F) for 15 to 20 minutes.