Résumé
Malaria is still the parasitic disease with the greatest worldwide impact. Recently in Brazil, almost all cases of the disease have been recorded in the Amazon region. The struggle against the vectors through insecticide treated nets associated with rapid diagnosis and treatment, is currently the main strategy. This study aimed to determine the protective effect of these devices on the incidence of malaria in one municipality in the Amazon, and was conducted with information from the Brazilian Ministry of Health and with the analysis of 10,050 slides of thick blood smears that were prepared and examined in loco. The Shapiro-Wilk test was used to determine the normality of the data and the Mann-Whitney test was used for all comparisons of the analyzed variables. The significance level was set at p≤0.01. The results revealed a significant reduction in the number of malaria cases in all analyzed variables, including the species of the parasite, the level and type of infection, and the gender and age of the diagnosed individual (pË0.01). These findings confirmed that these devices are an important tool for disease control, presenting a new variable in combating the disease in the studied population. Therefore, the use of insecticide-treated nets is recommended as a preventive measure and guidance to the population regarding the correct way to use this device is required to avoid problems such as the loss of naturally acquired immunity, reduction in the protective effect of the device and the development of resistance to the insecticide.