Typhoid Fever

What is Typhoid Fever?

Typhoid fever is an acute, life-threatening bacterial disease characterised by very high fever. It is caused by a germ called salmonella typhi, one of the many types of salmonella bacteria. Around 22 million cases of typhoid fever occur worldwide each year with about 200,000 related deaths.

How do you get Typhoid Fever?

The bacteria that cause typhoid fever are most often transmitted through consumption of water or food that has been contaminated by the feces of an acutely infected or convalescent person or a chronic, asymptomatic carrier of the germ. Humans are the only source of these bacteria.

Susceptibility and Resistance

Everyone can be susceptible to the infection. The risk is increased in people who have low levels of stomach acid or those who are HIV positive. Relative immunity follows recovery from typhoid fever, even when infection is unapparent. In endemic areas, typhoid fever is most common in preschool children and in young people 5 to 19 years of age.

Incubation Period

The incubation period for Typhoid Fever is 7-90 days.

What are the Symptoms?

The main symptom of typhoid infection is a persistent, high fever as high as 103° to 104° F (39° to 40° C). Other common symptoms and signs include headache, fatigue, loss of appetite, enlargement of the spleen, a rash of flat, rose-colored spots, a non-productive cough in the early stages, and relatively slowed heart rate. Mild infection can occur, as well as infection without any symptoms at all. Approximately 10 to 20 percent of people with untreated infections may die, but prompt antibiotic treatment reduces the death rate to less than 1 percent.

Preventative Measures

There are a couple of vaccines available to prevent typhoid fever where there is an increased risk of exposure, but these vaccines are not 100 percent effective.

Because the vaccines lack complete protection, travellers should avoid consuming unsafe food and water especially in small villages and rural areas where food and water safety cannot be guaranteed.


Antibiotics can shorten the course of typhoid fever and reduce the risk of death. Patients should be monitored to ensure that the high fever wanes within a few days of starting treatment. If the fever does not subside, different antibiotics should be considered.



Where Does It Commonly Occur?

The bacteria that causes typhoid fever occurs worldwide, especially in developing countries in Southeast Asia, Africa, the Caribbean and Central and South America. Occasionally it occurs in developed countries such as the United States.