Individual Plasmodium vivaxmsp1Variants within Polyclonal P. vivaxInfections Display Different Propensities for Relapse

ABSTRACTUsing a newly developed Plasmodium vivaxmerozoite surface protein 1 gene (Pvmsp1) heteroduplex tracking assay, we genotyped 107 P. vivaxinfections in individuals from Cambodia, 45 of whom developed recurrent parasitemia within 42 days. The majority of isolates were polyclonal, but recurrent parasitemias displayed fewer variants compared to initial parasitemias. Two Pvmsp1gene variants occurred more frequently in the initial genotypes of those who developed recurrent parasitemia, representing the first time P. vivaxvariants associated with a higher risk of relapse have been described.