Diverse allelic polymorphism of MSP-1 and MSP-2 was identified in P. falciparum isolates from Myanmar and most of the infections were determined to be mixed infections.
We present an MSP-1(19) allele-specific polymerase chain reaction (PCR)/ligase detection reaction-fluorescent microsphere assay (LDR-FMA) that allows simultaneous detection of the four predominant MSP-1(19) haplotypes with a sensitivity and specificity comparable with other molecular methods and a semi-quantitative determination of haplotype contribution in mixed infections.
This showed that the parasite population circulating in French Guiana presented a limited number of allelic forms (4, 2, and 3 for MSP-1 block 2, MSP-1, and GLURP, respectively) and a small number of mixed infections, contrasting with the large genetic diversity of parasite populations and infection complexity reported for Africa, Asia, and other parts of South America.
The proportion of genetically mixed infections (isolates with parasites carrying more than one MSP-1 version) ranged from 39% in Brazil to 44% in Vietnam and 60% in Tanzania.