The El Nino phenomenon, the warming of the equatorial Pacific Ocean that occurs every two to seven years, has been linked to outbreaks of dengue, malaria and cholera. Now, researchers from the Johns Hopkins School of Public Health, A.B. Prisma and the Instituto Nacional de Salud in Lima, Peru, have found that the 1997-98 El Nino season increased hospitalizations for diarrheal disease by 200 percent, according to a study published in the Feb. 5 issue of The Lancet. The results are cause for concern, said the researchers, since diarrhea already causes 1 billion episodes and 3 million deaths annually in children under 5 worldwide.

The researchers estimate that hospital admissions due to diarrheal disease increased by more than 8 percent with every 1 degree Celsius rise in temperature, results that will potentially increase diarrheal disease cases by millions worldwide with each degree of increase in ambient temperature due to global warming or other local factors.

A team of scientists led by William Checkley, a doctoral candidate at the School of Public Health, examined diarrheal disease hospital records for more than 57,000 children from 1993 to 1998 and found that admissions during the El Nino season increased significantly above expected norms. The admissions increase was particularly sharp during Peru's winter months, which are May to November.

Further information is available on the Child Health Research Project website, http://ih.jhsph.edu/chr/chr.htm as of February 3.