Colorized transmission electron micrograph of Avian influenza A H5N1 viruses (seen in gold) grown in MDCK cells (seen in green).

Photo: Cynthia Goldsmith (CDC)

Travel abroad for work or pleasure, or a combination of the two, can have unexpected health consequences many travellers are unprepared for.  The findings of a recent study led by Dr. David Freedman of the University of Alabama published in the New England Journal of Medicine provide a comprehensive look at the types of diseases most likely to strike travelers to particular areas of the world. 

Doctors in various countries including Germany, Nepal and the U.S. tracked diseases brought home by travelers to developing countries. The data from GeoSentinel came from 30 clinics in six regions of the world. They found the most common diseases were: illnesses causing fever like malaria and dengue fever, diarrheal illnesses from parasites, skin disorders from insect bites, and gastrointestinal disorders other than diarrhea (such as liver infections).

Between 1996 and 2004, more than 17,000 people who had recently traveled internationally visited those clinics due to health problems they brought home following their trips. More than 760 million people, including business travel and immigrants visits to their country of origin, crossed country borders in 2004, according to a journal editorial by David Hill (quoted in an article on WebMD ). Hill is the director of the National Travel Health Network and Center in London and an honorary professor at the London School of Hygiene and Tropical Medicine. He specializes in tropical medicine and hygiene.

GeoSentinel is a worldwide communication and data collection network for the surveillance of travel related morbidity.   It was initiated in 1995 by the International Society of Travel Medicine (ISTM) and the Centers for Disease Control (CDC) as a network of ISTM member travel/tropical medicine clinics.  GeoSentinel is based on the concept that these clinics are ideally situated to effectively detect geographic and temporal trends in morbidity among travelers, immigrants and refugees.

Details about the study are available at Freedman, D. The New England Journal of Medicine, Jan. 12, 2006; vol 354: pp 119-130. Hill, D. The New England Journal of Medicine, Jan. 12, 2006; vol 354: pp 115-117.