[Effect of bed nets impregnated with deltamethrin on malaria morbidity in an area of the Brazilian Amazones]. / Ação de mosquiteiros impregnados com deltametrina sobre a morbidade da malária em uma área da Amazônia Brasileira.

In 1992 an investigation regarding the value of insecticide impregnated mosquito nets was conducted in the municipality of Costa Marques, Rondonia. Impregnated mosquito nets gave similar protection to those not impregnated, without modifying the incidence of infection during the season of low transmission. The multivariate analysis for age and antibody titre showed a significant protection of impregnated nets against the risk of infection only in the season of high transmission, when bed nets were used more correctly. There was no difference in the effect of both kinds of bed nets in the prevention of high parasitaemia. At the end of the study, there was a reduction of the prevalence of splenomegaly in both groups but hematocrit values rose to normal in the below 15 year olds using impregnated nets.