Plasmodium vivax populations in the western Greater Mekong Subregion evaluated using a genetic barcode.

An improved understanding of the Plasmodium vivax populations in the Great Mekong Subregion (GMS) is needed to monitor the progress of malaria elimination. This study aimed to use a P. vivax single nucleotide polymorphism (SNP) barcode to evaluate the population dynamics and explore the gene flow among P.

Interventions for promoting patients' adherence to 14-day primaquine treatment in a highly malaria-endemic township in Myanmar: a qualitative study among key stakeholders.

Background: Plasmodium vivax malaria is considered a major threat to malaria eradication. The radical cure for P. vivax malaria normally requires a 14-day administration of primaquine (PQ) to clear hypnozoites.

Interventions for promoting patients' adherence to 14-day primaquine treatment in a highly malaria-endemic township in Myanmar: A qualitative study among key stakeholders.

Background: malaria is considered a major threat to malaria eradication. The radical cure for malaria normally requires a 14-day administration of primaquine (PQ) to clear hypnozoites. However, maintaining adherence to PQ treatment is a significant challenge, particularly in malaria-endemic rural areas.

Factors hindering coverage of targeted mass treatment with primaquine in a malarious township of northern Myanmar in 2019-2020.

Targeted mass primaquine treatment (TPT) might be an effective intervention to facilitate elimination of vivax malaria in Myanmar by 2030. In this study, we explored the factors hindering coverage of a TPT campaign conducted in a malarious township of northern Myanmar. From August 2019 to July 2020, a cross-sectional exploratory design including quantitative and qualitative data was conducted in five villages with high P.

Pf7: an open dataset of genome variation in 20,000 worldwide samples.

We describe the MalariaGEN Pf7 data resource, the seventh release of genome variation data from the MalariaGEN network.  It comprises over 20,000 samples from 82 partner studies in 33 countries, including several malaria endemic regions that were previously underrepresented.  For the first time we include dried blood spot samples that were sequenced after selective whole genome amplification, necessitating new methods to genotype copy number variations.

Spatio-temporal trends of malaria incidence from 2011 to 2017 and environmental predictors of malaria transmission in Myanmar.

Background: Myanmar bears the heaviest malaria burden in the Greater Mekong Subregion (GMS). This study assessed the spatio-temporal dynamics and environmental predictors of Plasmodium falciparum and Plasmodium vivax malaria in Myanmar.

Methods: Monthly reports of malaria cases at primary health centers during 2011-2017 were analyzed to describe malaria distribution across Myanmar at the township and state/region levels by spatial autocorrelation (Moran index) and spatio-temporal clustering.

Different In Vitro Drug Susceptibility Profile of Isolates from Two Adjacent Areas of Northeast Myanmar and Molecular Markers for Drug Resistance.

The Greater Mekong Subregion (GMS) is the epicenter of antimalarial drug resistance. We determined in vitro susceptibilities to 11 drugs of culture-adapted Plasmodium falciparum isolates from adjacent areas (Laiza and Muse) along the China−Myanmar border. Parasites from this region were highly resistant to chloroquine and pyrimethamine but relatively sensitive to other antimalarial drugs.

Genetic diversity in the transmission-blocking vaccine candidate Plasmodium vivax gametocyte protein Pvs230 from the China-Myanmar border area and central Myanmar.

Background: Sexual stage surface antigens are potential targets of transmission-blocking vaccines (TBVs). The gametocyte and gamete surface antigen P230, a leading TBV candidate, is critical for red blood cell binding during exflagellation and subsequent oocyst development. Here, the genetic diversity of Pvs230 was studied in Plasmodium vivax parasite isolates from the China-Myanmar border (CMB) and central Myanmar.

Malaria Research for Tailored Control and Elimination Strategies in the Greater Mekong Subregion.

The malaria landscape in the Greater Mekong Subregion has experienced drastic changes with the ramp-up of the control efforts, revealing formidable challenges that slowed down the progress toward malaria elimination. Problems such as border malaria and cross-border malaria introduction, multidrug resistance in Plasmodium falciparum, the persistence of Plasmodium vivax, the asymptomatic parasite reservoirs, and insecticide resistance in primary vectors require integrated strategies tailored for individual nations in the region. In recognition of these challenges and the need for research, the Southeast Asian International Center of Excellence for Malaria Research has established a network of researchers and stakeholders and conducted basic and translational research to identify existing and emerging problems and develop new countermeasures.

Multidisciplinary Investigations of Sustained Malaria Transmission in the Greater Mekong Subregion.

In the course of malaria elimination in the Greater Mekong Subregion (GMS), malaria epidemiology has experienced drastic spatiotemporal changes with residual transmission concentrated along international borders and the rising predominance of Plasmodium vivax. The emergence of Plasmodium falciparum parasites resistant to artemisinin and partner drugs renders artemisinin-based combination therapies less effective while the potential spread of multidrug-resistant parasites elicits concern. Vector behavioral changes and insecticide resistance have reduced the effectiveness of core vector control measures.

Spatiotemporal dynamics of malaria in Banmauk Township, Sagaing region of Northern Myanmar: characteristics, trends, and risk factors.

Background: While national malaria incidence has been declining in Myanmar, some subregions within the nation continue to have high burdens of malaria morbidity and mortality. This study assessed the malaria situation in one of these regions, Banmauk Township, located near the Myanmar-India border. Our goal was to provide a detailed description of the malaria epidemiology in this township and to provide some evidence-based recommendations to formulate a strategy for reaching the national malaria elimination plan.

Community structure and insecticide resistance of malaria vectors in northern-central Myanmar.

Background: Myanmar is one of the six countries in the Greater Mekong Subregion (GMS) of Southeast Asia. Malaria vectors comprise many Anopheles species, which vary in abundance and importance in malaria transmission among different geographical locations in the GMS. Information about the species composition, abundance, and insecticide resistance status of vectorial systems in Myanmar is scarce, hindering our efforts to effectively control malaria vectors in this region.

Therapeutic efficacy of chloroquine for uncomplicated Plasmodium vivax malaria in southeastern and western border areas of Myanmar.

Background: In the Greater Mekong Subregion of Southeast Asia, Plasmodium vivax malaria is endemic and causes significant morbidity. In this study, the efficacy of chloroquine for treating uncomplicated P. vivax malaria at the eastern and western borders of Myanmar was investigated.

Residual malaria among migrant workers in Myanmar: why still persistent and how to eliminate it?

Background: Residual malaria is probably an important source for the re-emergence of malaria infection in the elimination era. Assessment to identify the factors influencing residual malaria in high-risk groups is needed to develop evidence-based decisions by stakeholders and policymakers.

Methods: This study was conducted to explore the factors influencing the residual malaria infection among migrant workers in two sentinel sites (endemic vs.

The acceptability of targeted mass treatment with primaquine for local elimination of vivax malaria in a northern Myanmar township: a mixed-methods study.

Background: Radical cure of the Plasmodium vivax latent liver stage is required to effectively manage vivax malaria. Targeted mass treatment with primaquine may be an effective mechanism for reducing reservoirs of the disease. Since community engagement and high coverage are essential for mass treatment programs, this study aimed to determine the acceptability of mass primaquine treatment in a targeted community in a northern Myanmar township.

Predictors of malaria rapid diagnostic test positivity in a high burden area of Paletwa Township, Chin State in Western Myanmar.

Background: Despite major reductions in malaria burden across Myanmar, clusters of the disease continue to persist in specific subregions. This study aimed to assess the predictors of test positivity among people living in Paletwa Township of Chin State, an area of persistently high malaria burden.

Methods: Four villages with the highest malaria incidence from Paletwa Township were purposively selected.

Seroprevalence of toxoplasmosis among reproductive-aged women in Myanmar and evaluation of luciferase immunoprecipitation system assay.

Backgrounds: Primary infection with Toxoplasma gondii during pregnancy can pose serious health problems for the fetus. However, the epidemiological status of toxoplasmosis among reproductive-aged population in Myanmar is largely unknown. Although luciferase immunoprecipitation system (LIPS) assays for serodiagnosis of toxoplasmosis was developed mostly using mouse infection model, had not been tested by using field-derived human samples.

Efficacy of artemether-lumefantrine for treating uncomplicated Plasmodium falciparum cases and molecular surveillance of drug resistance genes in Western Myanmar.

Background: Currently, artemisinin-based combination therapy (ACT) is the first-line anti-malarial treatment in malaria-endemic areas. However, resistance in Plasmodium falciparum to artemisinin-based combinations emerging in the Greater Mekong Sub-region is a major problem hindering malaria elimination. To continuously monitor the potential spread of ACT-resistant parasites, this study assessed the efficacy of artemether-lumefantrine (AL) for falciparum malaria in western Myanmar.

Molecular surveillance for drug resistance markers in Plasmodium vivax isolates from symptomatic and asymptomatic infections at the China-Myanmar border.

Background: In the Greater Mekong sub-region, Plasmodium vivax has become the predominant species and imposes a major challenge for regional malaria elimination. This study aimed to investigate the variations in genes potentially related to drug resistance in P. vivax populations from the China-Myanmar border area.

Molecular epidemiology of resistance to antimalarial drugs in the Greater Mekong subregion: an observational study.

Background: The Greater Mekong subregion is a recurrent source of antimalarial drug resistance in Plasmodium falciparum malaria. This study aimed to characterise the extent and spread of resistance across this entire region between 2007 and 2018.

Methods: P falciparum isolates from Myanmar, Thailand, Laos, and Cambodia were obtained from clinical trials and epidemiological studies done between Jan 1, 2007, and Dec 31, 2018, and were genotyped for molecular markers (pfkelch, pfcrt, pfplasmepsin2, and pfmdr1) of antimalarial drug resistance.

Molecular Surveillance and in vitro Drug Sensitivity Study of Isolates from the China-Myanmar Border.

The emergence and spread of resistance in to the frontline treatment artemisinin-based combination therapies in Southeast Asia require close monitoring of the situation. Here, we collected 36 clinical samples of from the China-Myanmar border in 2014-2016, adapted these parasites to continuous culture, and performed in vitro drug assays on seven antimalarial drugs. Data for 23 parasites collected in 2010 and 2012 from the same area reported in an early study were used to assess longitudinal changes in drug sensitivity.

Plasmodium vivax HAP2/GCS1 gene exhibits limited genetic diversity among parasite isolates from the Greater Mekong Subregion.

Background: Antigens expressed in sexual stages of the malaria parasites are targets of transmission-blocking vaccines (TBVs). HAP2/GCS1, a TBV candidate, is critical for fertilization in Plasmodium. Here, the genetic diversity of PvHAP2 was studied in Plasmodium vivax parasite populations from the Greater Mekong Subregion (GMS).

Genetic diversity, natural selection and haplotype grouping of Plasmodium vivax Duffy-binding protein genes from eastern and western Myanmar borders.

Background: Merozoite proteins of the malaria parasites involved in the invasion of red blood cells are selected by host immunity and their diversity is greatly influenced by changes in malaria epidemiology. In the Greater Mekong Subregion (GMS), malaria transmission is concentrated along the international borders and there have been major changes in malaria epidemiology with Plasmodium vivax becoming the dominant species in many regions. Here, we aimed to evaluate the genetic diversity of P.