Norovirus may be the most common cause of travelers' diarrhea for United States citizens returning from Mexico and Guatamala say researchers from the U.S., Guatemala, Mexico and Sweden. Their findings appear in the March 2005 issue of the Journal of Clinical Microbiology.

It is estimated that 20 to 50 percent of the people traveling to tropical areas of the world will experience traveler's diarrhea (TD). TD, defined as three or more loose stool movements in a 24-hour period, frequently results from exposure to bacterial or viral pathogens. Noroviruses (NoV's) are considered to be one of the leading causes of nonbacterial gastro-related illnesses resulting in over 23 million cases annually.

In the study stool samples were collected from 34 patients with traveler's diarrhea and tested for the presence of norovirus. The virus was detected in 65 percent of the samples tested, with time spent at travel destinations playing an important role in determining infection frequency.

"This study is the first of its kind to indicate that NoVs may be a major cause of illness among United States travelers who experience TD during extended stays in developing countries," say the researchers. The high frequency of NoV infection among TD cases examined in this study suggests that further investigations concerning the role of these viruses in TD are warranted."

(A.R. Chapin, C.M. Carpenter, W.C. Dudley, L.C. Gibson, R. Pratdesaba, O. Torres, D. Sanchez, J. Belkind-Gerson, I. Nyquist, A. Karnell, B. Gustafsson, J.L. Halpern, A.L. Bourgeois, K.J. Schwab. 2005. Prevalence of norovirus among visitors from the United States to Mexico and Guatemala who experience traveler's diarrhea. Journal of Clinical Microbiology, 43. 3: 1112-1117.)

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Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology
18-Mar-2005