Plasmodium Vivax Transmission Dynamics and Superinfection Prevalence in the Peruvian Amazon

Malaria causes 300- 500 million clinical cases and over one million deaths each year.  Plasmodium vivax is the most widespread of the human malaria parasites and is the predominant cause of malaria in Central and Southeast Asia and South America.  Very little is known about the biology of P. vivax except that parasite populations are extremely genetically diverse in each endemic area.  The dynamics of P. vivax transmission have a large impact on the disease burden in an endemic area and regions with complex transmission dynamics allow parasite strains to more easily recombine. This recombination creates new hybrid parasite strains that could lead to the emergence of drug resistance and enhanced virulence.

In order to investigate the transmission dynamics in the region around our field site in Iquitos, Peru, we genotyped parasite strains from the 2008 transmission season at the merozoite surface protein-three alpha (msp-3α), a highly variable surface antigen.  Nested-PCR followed by restriction fragment length polymorphism analysis at msp3α allows us to identify the number of dominant haplotypes as well as the prevalence of super infection in the Peruvian Amazon.  Preliminary results suggest that polyclonal infections are currently present within this specified region; research is ongoing to ascertain the number of dominant haplotypes in and around Iquitos. Final results are anticipated to be completed in late summer to early fall 2012and the results obtained here will also be used to prioritize our whole genome sequencing analysis of P. vivax in the Peruvian Amazon.