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

The road to malaria elimination for low- and middle-income countries is paved with obstacles, including the complexity and high costs of advanced molecular methods for genomic analysis. The usefulness of PCR-RFLP as less complex and affordable molecular surveillance tool in low-endemic malaria regions was assessed in a cross-sectional study conducted in Suriname, currently striving for malaria elimination, but plagued by recent P. vivax outbreaks. Molecular analysis of two highly polymorphic genes Pvmsp-1 F2 and Pvmsp-3α was performed for 49 samples, collected during October 2019 through September 2021 from four different regions with varying malaria transmission risks. RFLP-profiling revealed that outbreak samples from three indigenous villages, almost exclusively, harbored a single clonal type, matching the "Palumeu" lineage previously described in 2019, despite multiple relapses and drug pressure exerted by mass drug administration events, suggesting a limited P. vivax hypnozoite reservoir in Suriname. In contrast, isolates originating from Sophie, a mining area in neighboring French Guiana displayed a highly heterogeneous parasite population consistent with its endemic malaria status, demonstrating the differentiating capacity and thus the usefulness of PCR-RFLP for P. vivax genetic diversity studies. Outbreak reconstruction emphasized the impact of undetected human movement and relapses on reintroduction and resurgence of P. vivax malaria and PCR-RFLP monitoring of circulating parasites guided the roll-out of targeted interventions. PCR-RFLP seems a suitable molecular alternative in low-endemic areas with restricted resources for outbreak analysis, for monitoring the spread or containment of circulating strains and for identification of imported cases or potential foci.

Reconstruction of Plasmodium vivax outbreaks in a low malaria endemic setting utilizing conventional restriction fragment length polymorphism.

Suriname is on track to eliminate local malaria transmission. P. vivax malaria reemerged in March and September 2019 in the Amerindian village Palumeu, free of malaria for two years and concurrently, a case was reported in another village Alalaparoe. The outbreaks were contained through targeted interventions including Mass Drug Administration (MDA). Molecular outbreak analysis was performed on 23 dried blood spots (DBS) using combined polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) with Pvmsp-1 F2 and Pvmsp-3α as polymorphic marker genes. Independent controls substantiated the discriminating capacities of the utilized PCR-RFLP method. All isolates from the first and second Palumeu outbreak shared a distinctive haplotype presuming single clonal lineage. An imported case probably triggered the first outbreak, while a delayed episode, prompted by withdrawal of drug pressure at the end of the prophylactic MDA, was suggested as source of the second outbreak. A diverging variant was demonstrated in Alalaparoe, implicating an infection from a different source. PCR-RFLP proved to be a useful molecular tool for P. vivax outbreak management in low endemic malaria settings.

First Assessment of Acquired HIV-1 Drug Resistance and Mutation Patterns in Suriname.

HIV drug resistance testing is fundamental in clinical patient management, but data on HIV-1 drug-resistant mutations (DRMs) is scarce in the Caribbean and in Suriname limited to one survey on transmitted resistance. The aim of this study was to address this gap, to gain insight in acquired HIV drug resistance (ADR) prevalence and mutation patterns, and to improve HIV-1 treatment outcome of people living with HIV (PLHIV) in Suriname. A prospective cross-sectional study was conducted from July 2018 through January 2019 among treatment-experienced PLHIV (n = 72), with either treatment failure or antiretroviral therapy restart. Genotypic drug resistance testing was performed and DRM impact on drug effectiveness was examined. Genotypic drug resistance testing revealed 97.2% HIV-1 subtype B, 2.8% B/D recombinants and a ADR prevalence of 63.2% in treatment failure patients, with a predominance of nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations. The most common DRMs were M184V (23.6%) and K103N (18.8%). A high level of non-DRM polymorphisms was observed in both the reverse transcriptase (RT) and protease (PR) gene. Interesting deviations from the existing mutation datasets were noted at position E248 and R83 of the RT gene and L63 and V77 in the PR gene. Full susceptibility to all examined drugs was 54.2%, while high-level drug resistance was estimated at 37.5%, which seems promising for treatment outcomes for PLHIV in Suriname, although cross-resistance to next-generation NNRTIs was already estimated for nearly a quarter of the patients. The meager 2.9% of PR DRMs rendered protease inhibitors as an effective rescue HIV-1 treatment.

Malaria serology data from the Guiana shield: first insight in IgG antibody responses to Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae antigens in Suriname.

BACKGROUND: Suriname has accomplished a steep decline in malaria burden, even reaching elimination levels. Plasmodium serology data are not available for Suriname and even extremely scarce within the region, therefore malaria serology testing was introduced, country customized cut-off values were determined and a study was performed to explore the antibody status for Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae. METHODS: A cross-sectional survey was conducted between July 2017 and March 2018 in two areas of the interior with different malaria settings: Stoelmanseiland, representing Maroon villages and Benzdorp, a gold mining area, with mostly Brazilian miners. Dried blood spots (DBS) were collected (n = 197) and antibody presence against seven Plasmodium antigens was detected using a multiplex bead-based, IgG antibody assay. Demographic information was gathered through a questionnaire. Country customized cut-off values were generated from a Surinamese malaria-naïve reference population (n = 50). RESULTS: Serological analysis for the reference population revealed cut-off values ranging from 14 MFI for LSA-1 to 177 MFI for PmMSP-119. Seroprevalence against any of the three MSP-119 antibodies was similar in both regions and surpassed 75%. Single seropositivity against PfMSP-119 antibodies was higher in Stoelmanseiland (27.0%) than Benzdorp (9.3%), in line with the historical malaria burden of Stoelmanseiland, while the reverse was observed for PvMSP-119 antibodies. Despite sporadic reports of P. malariae infections, PmMSP-119 antibody presence was 39.6%. A more detailed examination of P. falciparum serology data displayed a higher seroprevalence in villagers (90.7%) than in Brazilians (64.6%) and a highly diverse antigenic response with 22 distinct antibody combinations. CONCLUSIONS: The results on the malaria antibody signature of Maroon villagers and Brazilian miners living in Suriname displayed a high Plasmodium seroprevalence, especially for P. falciparum in villagers, still reflecting the historical malaria burden. The seroprevalence data for both regions and the observed combinations of P. falciparum antibodies provided a valuable dataset from a historically important region to the international malaria serology knowledge. First insight in malaria serology data for Suriname indicated that the use of other target groups and assessment of age-dependent seroprevalence are required to successfully use malaria serology as tool in the national elimination strategy.