Disease Description: Typhoid fever is an acute, life-threatening febrile illness caused by the bacterium Salmonella enterica serotype Typhi.
Risk to Travelers: Risk is greatest for travelers to South Asia and developing countries in Asia, Africa, the Caribbean, and Central and South America. Travelers have acquired typhoid fever even during brief visits of less than 1 week to countries where the disease is endemic.
Prevention - Vaccine: Two typhoid vaccines are currently available in the United States: an oral live, attenuated vaccine (Ty21a) and a Vi capsular polysaccharide vaccine (ViCPS) for intramuscular use. Both vaccines protect 50%-80% of recipients.
Vaccine Adverse Effects: Adverse reactions may include fever, headache, and local reactions (to the injection).
Vaccine Contraindications: Information is not available on the safety of these vaccines in pregnancy; it is prudent on theoretical grounds to avoid vaccinating pregnant women. Live, attenuated Ty21a vaccine should not be given to immunocompromised travelers, including those infected with HIV. The only contraindication to vaccination with ViCPS vaccine is a history of severe local or systemic reactions after a previous dose.
Vaccine Booster Recommendations: Booster dose every 2 years.
Information adapted from CDC Health Information for International Travel (the Yellow Book), http://www.cdc.gov/travel/yellowbook/2010/table-of-contents.htm