Spatiotemporal Changes in Plasmodium vivax msp142 Haplotypes in Southern Mexico: From the Control to the Pre-Elimination Phase

Abstract

For 20 years, Plasmodium vivax has been the only prevalent malaria species in Mexico, and cases have declined significantly and continuously. Spatiotemporal genetic studies can be helpful for understanding parasite dynamics and developing strategies to weaken malaria transmission, thus facilitating the elimination of the parasite. The aim of the current contribution was to analyze P. vivax-infected blood samples from patients in southern Mexico during the control (1993–2007) and pre-elimination phases (2008–2011). Nucleotide and haplotype changes in the pvmsp142 fragment were evaluated over time. The majority of multiple genotype infections occurred in the 1990s, when the 198 single nucleotide sequences exhibited 57 segregating sites, 64 mutations, and 17 haplotypes. Nucleotide and genetic diversity parameters showed subtle fluctuations from across time, in contrast to the reduced haplotype diversity and the increase in the R2 index and Tajima’s D value from 2008 to 2011. The haplotype network consisted of four haplogroups, the geographical distribution of which varied slightly over time. Haplogroup-specific B-cell epitopes were predicted. Since only high-frequency and divergent haplotypes persisted, there was a contraction of the parasite population. Given that 84% of haplotypes were exclusive to Mesoamerica, P. vivax flow is likely circumscribed to this region, representing important information for parasite surveillance.

Plasmodium vivax MSP1-42 kD Variant Proteins Detected Naturally Induced IgG Antibodies in Patients Regardless of the Infecting Parasite Phenotype in Mesoamerica

“…P. vivax -infected blood samples displaying different PvMSP1 42 haplotypes from southern Mexico [ 20 ] were used to produce three recombinant proteins ( Figure S1 ). These variant proteins mirror the most frequent and divergent haplotypes from different haplogroups (HgA, HgB, and HgD) previously reported for Southern Mexico, which have fluctuated over time [ 20 ].…”

“…P. vivax -infected blood samples displaying different PvMSP1 42 haplotypes from southern Mexico [ 20 ] were used to produce three recombinant proteins ( Figure S1 ). These variant proteins mirror the most frequent and divergent haplotypes from different haplogroups (HgA, HgB, and HgD) previously reported for Southern Mexico, which have fluctuated over time [ 20 ]. The diagnosis of P. vivax infection was made in symptomatic patients via a microscopy examination of a thick blood smear stained with Giemsa, as reported previously [ 19 , 20 ].…”

“…One-hundred and fourteen plasma samples and 64 blood samples impregnated onto filter paper from P. vivax patients were obtained from two sites of the Mesoamerican region, in southern Mexico (2002–2009) and Nicaragua (2012–2013) [ 19 , 20 ], respectively. All samples were preserved at −80 °C until use.…”

“…All samples were preserved at −80 °C until use. The PvMSP1 42 phenotypes of the parasites from those infected individuals were previously published [ 19 , 20 ]. A group of 36 plasma samples from individuals with no history of P. vivax infection were also evaluated and used to estimate the cut-off value.…”

“…P. vivax MSP1-42 kD (PvMSP1 42 ) is the C-terminal fragment participating in the first contact of the reticulocyte prior merozoite invasion, and consists of two fragments of 33 kD (PvMSP1 33 ) and 19 kD (PvMSP1 19 ). In the Mesoamerican region, PvMSP1 33 has a polymorphic segment and PvMSP1 19 is highly conserved [ 19 , 20 ]. PvMSP1 19 has been shown to be highly immunogenic and successful in monitoring the transmission of malaria in some countries [ 6 , 21 ].…”