Effects of the El Nino phenomenon and ambient temperature on hospital admissions for diarrheal disease The Lancet Feb. 5, 2000 William Checkley, Leonardo Epstein, Robert H Gilman, Dante Figueroa, Rosa I Cama, Jonathan Patz, & Robert E Black

What is El Niño? West trade winds keep the warm waters of the central Pacific Ocean in place Normal conditions El Niño conditions West trade winds weaken and the warm waters of the central Pacific Ocean move towards the equatorial Pacific until they reach the South American coast

El Niño is associated with dengue, malaria, and cholera. Now, researchers have found that El Niño increases hospital admissions for diarrheal disease by 200%. Public Health Significance I

Researchers estimate that diarrheal disease admissions increased by more than 8% with every 1 degree C. rise in temperature; There could be an increase of cases in the millions in diarrheal disease cases worldwide with each degree of increase in ambient temperature due to global warming. Public Health Significance II

Whether the El Niño episode had an effect on hospital admissions for diarrheal disease. The relationship between weather variability and diarrheal diseases. The study examined

Daily admissions to the Oral Rehydration Unit (ORU) of the Instituto Nacional del Niño, Lima, Peru – from January 1,1993 to Nov 15, Over 57,000 diarrheal admissions during the study period. Information on each child at the time of admission included: age (all children < 10), weight and height (nutritional status), and severity status. Methods

Daily mean ambient temperature and relative humidity in Lima (Jan 1993 to Nov 1998) obtained from SENAMHI. Definitions: El Niño period as January 1, 1997 to August 31, Extension of the global ENSO definition to account for local differences in weather. Methods

Loss of periodic, pre-El Niño pattern and significant increase above normal during El Niño (p < 0.001); Observed temperature was consistently higher than normal. On several days it was > 5 oC above normal; Decline in excess temperature began around June 1998; lower than normal by September RESULTS Effects of El Niño on ambient temperature in Lima

During El Niño, diarrheal admissions also lost their periodic, pre-El Niño pattern and increased significantly above normal (p < 0.001); Observed admissions were uniformly larger than expected. In the winter, daily admissions increased up to 200 percent above expected; 6,225 admissions were attributable to El Niño and cost the ORU $ 277,000. RESULTS Effects of El Niño on ambient temperature in Lima

El Nino increased diarrheal admissions, especially during the winter when admissions increased by 200 percent; An increase of 8% in admissions per 1 degree C increase suggests that global warming is likely to have a strong effect on diarrheal diseases – increasing cases by millions worldwide per degree temperature increase, and Early warning of future El Nino episodes can help us better treat and prevent cases of diarrheal illness. Key Points