August 27, 2009

U.S. typhoid cases linked to travel

Researchers say most U.S. cases of typhoid fever are related to travel -- especially the Indian subcontinent.

The study, published in the Journal of the American Medical Association, finds more and more typhoid cases are being identified as drug-resistant strains, including nalidixic acid-resistant S Typhi as well as ciprofloxacin-resistant. The researchers raise concerns that strains resistant to fluroquinolones may become more prevalent.

Over the last 20 years, emergence of S Typhi strains resistant to anti-microbial agents has complicated treatment of infected patients, the study authors say in a statement. Reducing the burden of typhoid fever in the United States will require increased attention to prevention measures by travelers, including improved vaccination coverage among travelers to typhoid-endemic areas.

The Centers for Disease Control and Prevention study, led by Dr. Michael Lynch, was based on data from 1999-2006 for 1,902 people with typhoid fever submitted to the CDC, and 2,016 S Typhi isolates from public health laboratories sent to the CDC for anti-microbial susceptibility testing.