IAMAT |International Association of Medical Assistance to Travellers| IAMAT |International Association of Medical Assistance to Travellers|

Typhoid Fever

Photo By: Huiquan Yang

Typhoid Fever is a gastrointestinal infection caused by Salmonella enterica typhi bacteria. It is transmitted from person to person through the fecal-oral route where an infected or asymptomatic individual (who does not exhibit symptoms) with poor hand or body hygiene passes the infection to another person when handling food and water. The bacteria multiply in the intestinal tract and can spread to the bloodstream. Paratyphoid fever, a similar illness, is caused by Salmonella enterica paratyphi A, B, and C.


The bacteria are present in many Southeast Asian countries as well as in Africa, Central and South America, and Western Pacific countries in areas where there is poor water and sewage sanitation. Floods in these regions can also quickly spread the bacteria. All travellers going to endemic areas are at risk, especially long-term travellers, adventure travellers, humanitarian workers,  and those visiting friends or relatives in areas with poor sanitation. Note that original infection does not provide immunity to subsequent infections.


Usually symptoms appear 1 to 3 weeks after exposure to the bacteria. Depending on the virulence of the infection symptoms can range from mild to severe. The illness is characterized by extreme fatigue and increasing fever. Other symptoms include headache, lack of appetite, malaise, and an enlarged liver. Sometimes patients have diarrhea, constipation, or a rash on their trunk. Severe symptoms may appear 2 to 3 weeks after onset of the illness and may include intestinal hemorrhage or perforation. Some people who recover from Typhoid Fever and Paratyphoid Fever continue to be carriers of the bacteria and can potentially infect others. Treatment includes antibiotics and supportive care of symptoms. Antibiotic resistance to S. typhii is increasing worldwide.


Wash your hands frequently and thoroughly, and practice proper body hygiene. Drink purified water (boiled or untampered bottled water) and only eat well cooked foods. Use the mantra Boil it, Cook it, Peel it, or Forget it!


There are two types of vaccines available; the inactivated injectable vaccine (lasting 2-3 years) and the live attenuated oral vaccine (lasting 5-7 years). Discuss your best options with your healthcare provider, including revaccination schedules which differ in the USA and Canada. A combined Typhoid Fever and Hepatitis A vaccine is also available in Canada and Europe. Although Typhoid Fever vaccines do not provide 100% protection, they will reduce the severity of the illness. There is no vaccine available against Paratyphoid Fever.

Salmonella enterica typhi bacteria images, life cycle, and distribution maps:

Infection Landscapes

Information last updated: July 22, 2020

Vaccination is recommended if travelling to the following countries: