The authors present a short review on the evolution of malaria incidence in the Brazilian Amazon, with particular reference to the Rondônia State and the Municipality of Porto Velho, where dramatic epidemics of malaria and other tropical diseases have been registered in the past. Next, they analyze the present endemic malaria situation in the Madeira River Valley where two important Hydroelectric Power Plants will be constructed in the localities of Santo Antônio and Jirau. Longitudinal surveys performed in the last four years in this area allow to demonstrate a high prevalence of symptomatic and asymptomatic malaria carriers in the area, associated to the presence of high densities of the malaria vector Anopheles darlingi all over the year. These elements are correlated to the expected arrival of a large number of human migrants originated from non endemic areas of Rondônia and other Brazilian States, attracted by the possibility of jobs in the Hydroelectric Power Plants and by secondary opportunities in commerce, leisure, education and domestic activities. These associations create favorable conditions for malaria outbreaks and other tropical diseases that must be avoided by the establishment of additional control measures, in particular in the sanitation domain
Epidemics; Malaria; Asymptomatic Carrier; Hydro power station; Amazon region
