Unvaccinated travellers who make even short-term visits to countries where typhoid fever is endemic, including India, Pakistan, Bangladesh, Mexico, Philippines and Haiti, are at risk of contracting the disease, according to an article published in a science journal in Washington.
Salmonella Typhi is the typhoid fever-causing bacterium that infects people who consume contaminated food or water. Symptoms of the illness, which can be fatal if left untreated, may include fever, rash, stomach ache, slowed pulse, enlarged spleen and delirium.
The study, conducted by researchers from the US Center for Disease Control and Prevention (CDC) and the University of Washington, examined nearly 1,400 typhoid fever cases reported from 1994 through 1999. Three-quarters of the cases were associated with international travel, and six countries - India, Pakistan, Mexico, Bangladesh, Philippines and Haiti - were the sources of 76% of the travel-related typhoid fever.
Only 4% of the patients had been immunized against typhoid fever within five years of travelling, the article published in the July 15 issue of Clinical Infectious Diseases said.
Why do so few travelers get vaccinated if the risk of illness is so high? "Many probably do not seek travel advice and are unaware of the risks of typhoid fever," said Dr Ellen Steinberg Stevenson of the CDC.
She recommends that people prepare for those risks by visiting travel medicine clinics before going on international trips.