Post-disaster malaria in Costa Rica.

Abstract

In recent years, controversy has surrounded the issue of whether infectious disease should be considered a serious potential consequence of natural disasters. This article contributes to this debate with evidence of a significant outbreak of malaria in Costa Rica's Atlantic region after the 1991 earthquake and subsequent floods. This study is an epidemiologic investigation of the incidence of malaria for the periods of 22 months before the April 1991 Limón earthquake and for 13 months afterward. Data were obtained from the Costa Rican Ministry of Health's malaria control program. Some of the cantons in the region experienced increases in the incidence of malaria as high as 1,600% and 4,700% above the average monthly rate for the preearthquake period (p < or = 0.01). Causal mechanisms are postulated as relating to changes in human behavior (increased exposure to mosquitoes while sleeping outside, and a temporary pause in malaria control activities), changes in the habitat that were beneficial to mosquito breeding (landslide deforestation, river damming, and rerouting), and the floods of August 1991. It is recommended that there be enhanced awareness of the potential consequences of disaster-wrought environmental changes. Date of Event: 22 April 1991; Type: Earthquake, 7.4 Richter scale; Costa Rica; Number of deaths and casualties: 54 deaths and 505 moderate to severe injuries.