Plasmodium vivax Genetic Diversity in Panama: Challenges for Malaria Elimination in Mesoamerica

Abstract

Panama and all nations within the Mesoamerican region have committed to eliminate malaria within this decade. With more than 90% of the malaria cases in this region caused by Plasmodium vivax, an efficient national/regional elimination plan must include a comprehensive study of this parasite’s genetic diversity. Here, we retrospectively analyzed P. vivax genetic diversity in autochthonous and imported field isolates collected in different endemic regions in Panama from 2007 to 2020, using highly polymorphic markers (csp, msp-1, and msp-3α). We did the analysis using molecular techniques that are cost-effective for malaria molecular surveillance within Mesoamerica. Thus, we used molecular analyses that are feasible for malaria molecular surveillance within the region, and that can provide useful information for policy and decision making about malaria elimination. We also evaluated if haplotypes established by combining the genotypes found in these genes were associated with relevant epidemiological variables and showed structure across the transmission foci that have been observed in Panama. Ten different haplotypes were identified, some of them strongly associated with geographical origin, age, and collection year. Phylogenetic analysis of csp (central repeat domain) revealed that both major variant types (vk210 and vk247) were circulating in Panama. Variant vk247 was restricted to the eastern endemic regions, while vk210 was predominant (77.3%) and widespread, displaying higher diversity (14 alleles) and geographically biased alleles. The regional implications of these molecular findings for the control of P. vivax malaria to achieve elimination across Mesoamerica are discussed.

Insights into the Genetic Diversity of Leishmania (Viannia) panamensis in Panama, Inferred via Multilocus Sequence Typing (MLST)

“…The western region showed higher haplotype diversity indexes and outnumbered the eastern region in the number of haplotypes. Differences in genetic diversity at the haplotype level between these two regions have also been reported for Plasmodium vivax [37]. In the case of P. vivax, it was suggested that different ecological and climate conditions as well as vector diversity prevalent in both areas have influenced local malaria transmission and therefore the genetic structure of Plasmodium.…”

Spatiotemporal Analysis of Malaria Transmission in the Autonomous Indigenous Regions of Panama, Central America, 2015–2022

“…Recent molecular studies have shown that P. falciparum parasites circulating in this eastern region are resistant to chloroquine and partially resistant to antifolates [ 21 , 22 , 23 ], a resistant profile not observed in P. falciparum parasites circulating in the rest of the Mesoamerican countries. It has also been described that malaria parasites from the eastern side have a higher genetic diversity [ 24 , 25 ], as well as a higher vector species richness [ 26 ]. The ecological conditions also differed, particularly in the amount and seasonal distribution of rainfall, mean annual temperatures, daily fluctuations in temperature, and landcover [ 27 ].…”

Advocating for PCR-RFLP as molecular tool within malaria programs in low endemic areas and low resource settings

“…Recent use of this tool has been successful in Plasmodium vivax (P. vivax) investigations, to provide insight in genetic diversity in Panama [11] and for reconstruction of a malaria outbreak in a low transmission area [12]. In addition, PCR-RFLP has been utilized to assess the geographic origin of Plasmodium falciparum strains (P. falciparum) in Central America [3].…”