Melatonin in feverfew and other medicinal plants.

1598 Vol 350 • November 29, 1997 35% relative to the first trimester, in contrast to the 16% average decrease in the years 1993–96. During the third trimester of 1997, the number of cases of diarrhoea decreased, yet were still 25% above the figures seen in previous years for the same trimester. In Peru and neighbouring countries affected by El Niño— Chile, Ecuador, and Colombia—we anticipate an outbreak of diarrhoea and dehydration in the coming summer months when the high seasonal temperatures will be exacerbated by the presence of El Niño. This outbreak will burden local health services treating infections and/or diseases for which temperature may be an important determinant. Should we prepare for another cholera outbreak? Over the past 2 years, few cases of cholera have been seen in Peru, mainly, we think, because there was no susceptible population left after the huge 1991 and 1992 outbreaks. Children born after 1991 and 1992 who were neither infected nor exposed to Vibrio cholerae are the most susceptible population now. V cholerae can survive in a dormant stage in cool, brackish water, in association with plankton. When the water temperature rises, plankton blooms, and the population of V cholerae increases. R Colwell has suggested that remote satellite sensing of plankton beds might be used as an early warning system to help predict outbreaks of cholera. Analysts have examined the agricultural and economic implications of El Niño. Our data lead us to believe that it is equally imperative that we begin to examine El Niño’s implications on health and health care.