title: Plasmodium falciparum and Plasmodium vivax infections in the Peruvian Amazon: propagation of complex, multiple allele-type infections without super-infection.
abstract: Outcrossing potential between Plasmodium parasites is defined by the population-level diversity (PLD) and complexity of infection (COI). There have been few studies of PLD and COI in low transmission regions. Since the 1995-1998 Peruvian Amazon epidemic, there has been sustained transmission with < 0.5 P. falciparum and < 1.6 P. vivax infections/person/year. Using weekly active case detection, we described PLD by heterozygosity (H(e)) and COI using P. falciparum Pfmsp1-B2 and P. vivax Pvmsp3alpha. Not being homologous genes, we limited comparisons to within species. P. falciparum (N = 293) had low (H(e) = 0.581) and P. vivax (N = 186) had high (H(e) = 0.845) PLD. A total of 9.5% P. falciparum infections and 26.3% P. vivax infections had COI > 1. Certain allele types were in more mixed infections than expected by chance. The few appearances of new alleles could be explained by stochastic polymerase chain reaction detection or synchronization/sequestration. The results suggest propagation of mixed infections by multiple inocula, not super-infection, implying decade-long opportunity for outcrossing in these mixed infections.
authors.affiliation: Department of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Sutton
authors.forename: Victor
authors.initials: V
authors.lastname: Neyra
authors.forename: Jean N
authors.initials: JN
authors.lastname: Hernandez
authors.forename: Oralee H
authors.initials: OH
authors.lastname: Branch
mesh_terms: D000483:Alleles; D000818:Animals; D005786:Gene Expression Regulation; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology*; D016780:Malaria, Vivax / Q000453:epidemiology / Q000469:parasitology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D010568:Peru / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000235:genetics*; D010966:Plasmodium vivax / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D015800:Protozoan Proteins