DrAndre Siqueira

Multicentre Collaborative Study and Network studying the natural history and response to therapeutics amongst Chikungunya-affected individuals.

With reduced malaria transmission intensity, as observed in Brazil, low-density infections and alternative causes of fever assume higher proportional relevance. Addressing these two major issues is of great importance for public health in the Amazon region and need to be further investigated. Aims: Two lines of research will address present shortfalls in the clinical and laboratory-based diagnosis of malaria. The proposal aims to: (i) investigate the aetiology of acute febrile illness (AFS) amongst children seeking for healthcare at peri-urban and rural health centres in the Amazon region with the focus of generating clinical and laboratorial algorithms for case management and referral to tertiary centres. (ii) gain knowledge on the prevalence of very low density asymptomatic malaria infections that are below the detection limit of standard diagnosis in the field (microscopy, rapid diagnostic tests) and investigate the relevance of low density infections for onward transmission. Methods (i) Development of a research protocol to characterize the aetiology of AFS in the Amazon region proposing algorithms for patient management to be implemented in the region. (ii) Ultra-sensitive molecular methods will be applied for the diagnosis of P. falciparum and P. vivax. Samples will be analysed by highly sensitive quantitative PCR and reverse transcription PCR. (iii) Membrane and direct blood feeding assays performed with blood samples from sub-microscopic but qPCR-positive household contacts will be conducted in Manaus using Anopheles aquasalis colonies, with the aim to assess the infectivity of low density infections and their potential for transmission. Expected outcomes are: 1) The development of recommendations for clinical management and referral in rural and peri-urban areas of the Amazon region; 2)A strategy to precisely and reliably estimate P. falciparum and P. vivax prevalence; 3) Knowledge about infectivity of low density infections.