Human malaria transmission risk in an implementation area of mineral prospection, Juruti Municipality, Para State, Brazil

Abstract

This study aimed at evaluating human malaria transmission in the Juruti area, from
2006 to 2008. A total of 976 mosquitoes were collected by protected human attraction, identified, and processed for the determination of infectivity by ELISA and, part of them (10%), for assessing the parity rate. An haemoscopic survey was carried out in two occasions (September/2007 in the Capiranga Community and Nova Vitória
settlement, and in March 2008 in the latter community) using the thick smear technique (TS). We identified 8 species of anopheline mosquitoes; the predominant one was An. albitarsis s.l (76.8%). The parity rate for this species was 9.6%. The infectivity index was 0 (zero) for the first two years of the study and 0.5 for the last one (2008), when an exemplar of An. albitarsis s.l collected in the Santa Maria community was positive for P. vivax VK 247. The index of bite per man per hour ranged from 0.1 to 8.1. All 148 blood samples were negative by TS. Even with the presence of vector mosquitoes, the risk of malaria transmission in this area is low, since no infected individual was detected. However, it is necessary to keep the area under permanent surveillance, mainly because of the intense migratory flux due to the project activities.