Typhoid Fever
Symptoms
The bacterium Salmonella typhi causes typhoid fever, a disease characterized by sustained fever, headaches, abdominal pain, fatigue and constipation. On occasion, diarrhea may follow constipation. Some people may develop a skin rash. An enlargement of the spleen and liver has also been observed. If the infection is not treated with antibiotics, serious intestinal complications may develop around the third week.
Transmission
The bacterium Salmonella typhi is transmitted through the consumption of food or water contaminated with the feces of infected individuals. It can also be transmitted through direct contact with the stool of an infected person. The risk of transmission is highest in the developing parts of the world such as India, Southeast Asia, Africa, and Latin America. The incubation period lasts 1 to 3 weeks. Individuals can transmit the disease as early as 1 week after infection and some people will become lifelong chronic carriers.
Prevention
Take the following measures to prevent typhoid fever:
- wash hands with soap and water before handling food;
- wash hands with soap and water before eating and after using the toilet;
- avoid potentially contaminated foods and beverages.
Immunization
There are two types of typhoid vaccines, one is administered as an injection while the other is administered orally. The efficacy of the vaccines is approximately 50%. Vaccines are recommended for most people 2 years and older travelling to countries where the risk of transmission is considered high. It may also be considered for those travelling to countries where there is a risk of transmission based on individual risk factors (e.g., children, close contact with the local population, travel outside tourist areas with poor sanitation, or extended stay). Revaccination is recommended for those at repeated or continuous risk of exposure to typhoid fever every 3 or 7 years, depending on the type of vaccine.