RISK-FACTORS FOR MALARIA - A MICROEPIDEMIOLOGICAL STUDY IN A VILLAGE IN SRI-LANKA

Environmental and socioeconomic risk factors for malaria were studied in a village in Sri Lanka. Over a period of one year, all 49 household s in the village were visited every alternate day to obtain informatio n on malaria episodes. Information on risk factors was obtained throug h questionnaires and direct observations. Age below 17 years (relative risk [RR]=1.66, 95% confidence interval [95% CI] 1.18-2.35), use of b ed nets (RR=0.16, 95% CI 0.05-0.45) and traditional fumigants (RR=0.58 , 95% CI 1.37-0.93) were independent predictors of malaria. People usi ng anti-mosquito pyrethrum coils had a higher risk for malaria than pe ople living in houses where they were not used (RR=1.46, 95% CI 1.03-2 .07).The build-up of Anopheles culicifacies populations before the sta rt of the transmission season had taken place in a stream near the vil lage. Living close to the stream was a risk factor for malaria early i n the transmission season, although this did not reach statistical sig nificance (comparing <250 m with >500 m, RR=2.13, 95% CI 0.96-4.71).