[KOLKATA] Scientists have identified the norovirus as a major cause of diarrhoea in travellers to certain developing countries.
Researchers led by Hoonmo Koo, a physician at the US-based Baylor College of Medicine, found evidence that the norovirus poses a threat to people visiting Guatemala, India and Mexico.
Every year, 20–50 per cent of international travellers — an estimated ten million individuals — suffer diarrhoea, according to the Department of Health and Human Services at the US Centers for Disease Control and Prevention.
Koo and his team identified norovirus as the bug most responsible for travellers' diarrhoea or 'stomach flu', after the bacterium Escherichia coli.
The team collected stool samples from 571 international travellers who had acquired diarrhoea in Guatemala, India and Mexico, and norovirus showed up in one out of every ten samples.
In India, 23 of the 194 (11.9 per cent) stool samples showed norovirus as the cause while in Guatemala and Mexico the virus was responsible in 17 per cent (17 out of 100 samples) and 3.8 per cent (three out of 79 samples) of cases, respectively.
"Noroviruses are important pathogens of travellers' diarrhoea in multiple regions of the world. They have likely been underestimated as a cause of travellers' diarrhoea in the past because of the limited availability of current detection methods," Koo told SciDev.Net.
"Travellers to India may be affected by norovirus or E. coli as these are important enteric [diarrhoea-causing bugs] in this part of the world," said Triveni Krishnan, a scientist at the Division of Virology, National Institute of Cholera and Enteric Diseases in Kolkata, India.
"Travellers should take oral rehydrating solution [to replace lost body fluids] and consult a medical practitioner immediately upon onset of diarrhoea; they may step up personal hygiene by washing hands before meals, eating freshly cooked food, [and] drinking only mineral water from sealed bottles," Krishnan said.
"A vaccine for noroviruses is currently under investigation but is not yet available. Otherwise, rehydration is very important to avoid complications from travellers' diarrhoea," Koo said.
Their findings have been published, online (March 2010) in the Journal of Clinical Microbiology
Link to abstract in Journal of Clinical Microbiology
J. Clin. Microbiol. doi:10.1128/JCM.02072-09 (2010)