Effectiveness of a tailored forest package of interventions, including topical repellents, in reducing malaria incidence in Myanmar.

Background: In Myanmar, progress towards malaria elimination has stagnated in some areas requiring deployment of new tools and approaches to accelerate malaria elimination. While there is evidence that networks of community-based malaria workers and insecticide-treated nets (ITNs) can reduce malaria transmission in a variety of settings, evidence for the effectiveness of other interventions, such as topical repellents, is limited. Since malaria transmission in Myanmar occurs outdoors, mainly among forest-goers, this study tested the effectiveness of topical repellents in combination with supplemental ITN distribution and strengthened networks of malaria workers.

Artemisinin resistance in the malaria parasite, Plasmodium falciparum, originates from its initial transcriptional response.

The emergence and spread of artemisinin-resistant Plasmodium falciparum, first in the Greater Mekong Subregion (GMS), and now in East Africa, is a major threat to global malaria elimination ambitions. To investigate the artemisinin resistance mechanism, transcriptome analysis was conducted of 577 P. falciparum isolates collected in the GMS between 2016-2018.

Genetic surveillance in the Greater Mekong subregion and South Asia to support malaria control and elimination.

Background: National Malaria Control Programmes (NMCPs) currently make limited use of parasite genetic data. We have developed GenRe-Mekong, a platform for genetic surveillance of malaria in the Greater Mekong Subregion (GMS) that enables NMCPs to implement large-scale surveillance projects by integrating simple sample collection procedures in routine public health procedures.

Methods: Samples from symptomatic patients are processed by SpotMalaria, a high-throughput system that produces a comprehensive set of genotypes comprising several drug resistance markers, species markers and a genomic barcode.

Genetic polymorphism of vir genes of Plasmodium vivax in Myanmar.

The Plasmodium vivax variant proteins encoded by vir genes are highly polymorphic antigens and are considered as one of key proteins of P. vivax for host immune evasion via antigenic variations. Because genetic diversity of these antigens is a critical hurdle in the development of an effective vaccine, understanding the genetic nature of the vir genes in natural population is important.

Genetic variations in histidine-rich protein 2 and histidine-rich protein 3 of Myanmar Plasmodium falciparum isolates.

Background: Malaria rapid diagnostic tests (RDTs) are precious tools to diagnose malaria. Most RDTs used currently are based on the detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP2) in a patient's blood. However, concern has been raised in recent years that deletion of pfhrp2 in the parasite could affect the accuracy of PfHRP2-based RDTs.

Efficacy and Safety of Pyronaridine-Artesunate for the Treatment of Uncomplicated and Malaria in Myanmar.

Four single-arm, prospective, clinical studies of pyronaridine-artesunate efficacy in uncomplicated or malaria were conducted in Myanmar between 2017 and 2019. Eligible subjects were aged at least 6 years, with microscopically confirmed ( = 196) or mono-infection ( = 206). Patients received pyronaridine-artesunate once daily for 3 days with follow-up until day 42 for or day 28 for .

Triple artemisinin-based combination therapies versus artemisinin-based combination therapies for uncomplicated Plasmodium falciparum malaria: a multicentre, open-label, randomised clinical trial.

Background: Artemisinin and partner-drug resistance in Plasmodium falciparum are major threats to malaria control and elimination. Triple artemisinin-based combination therapies (TACTs), which combine existing co-formulated ACTs with a second partner drug that is slowly eliminated, might provide effective treatment and delay emergence of antimalarial drug resistance.

Methods: In this multicentre, open-label, randomised trial, we recruited patients with uncomplicated P falciparum malaria at 18 hospitals and health clinics in eight countries.

Genetic diversity of Plasmodium vivax and Plasmodium falciparum lactate dehydrogenases in Myanmar isolates.

Background: Plasmodium lactate dehydrogenase (pLDH) is a major target in diagnosing the erythrocytic stage of malaria parasites because it is highly expressed during blood-stage parasites and is distinguished from human LDH. Rapid diagnostic tests (RDTs) for malaria use pLDH as a target antigen; however, genetic variations in pLDH within the natural population threaten the efficacy of pLDH-based RDTs.

Methods: Genetic polymorphisms of Plasmodium vivax LDH (PvLDH) and Plasmodium falciparum LDH (PfLDH) in Myanmar isolates were analysed by nucleotide sequencing analysis.

Artemether-Lumefantrine and Dihydroartemisinin-Piperaquine Retain High Efficacy for Treatment of Uncomplicated Malaria in Myanmar.

The emergence of artemisinin-resistant in the Greater Mekong Subregion threatens both the efficacy of artemisinin-based combination therapy (ACT), the first-line treatment for malaria, and prospects for malaria elimination. Monitoring of ACT efficacy is essential for ensuring timely updates to elimination policies and treatment recommendations. In 2014-2015, we assessed the therapeutic efficacies of artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) for the treatment of uncomplicated at three study sites in Rakhine, Shan, and Kachin states in Myanmar.

Seroprevalence of Toxoplasma gondii among School Children in Pyin Oo Lwin and Naung Cho, Upper Myanmar.

Toxoplasma gondii is an apicomplexan parasite that can cause toxoplasmosis in a wide range of warm-blooded animals including humans. In this study, we analyzed seroprevalence of T. gondii among 467 school children living in the rural areas of Pyin Oo Lwin and Naung Cho, Myanmar.

Genetic polymorphism and natural selection of circumsporozoite surface protein in Plasmodium falciparum field isolates from Myanmar.

Background: Plasmodium falciparum circumsporozoite protein (PfCSP) is one of the most extensively studied malaria vaccine candidates, but the genetic polymorphism of PfCSP within and among the global P. falciparum population raises concerns regarding the efficacy of a PfCSP-based vaccine efficacy. In this study, genetic diversity and natural selection of PfCSP in Myanmar as well as global P.

Genetic diversity of merozoite surface protein-1 C-terminal 42 kDa of Plasmodium falciparum (PfMSP-1) may be greater than previously known in global isolates.

Background: The C-terminal 42 kDa region of merozoite surface protein-1 of Plasmodium falciparum (PfMSP-1) is the target of an immune response. It has been recognised as one of the promising candidate antigens for a blood-stage malaria vaccine. Genetic structure of PfMSP-1 has been considered to be largely conserved in the P.

Prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency among malaria patients in Upper Myanmar.

Background: Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.

Population genetic structure and natural selection of Plasmodium falciparum apical membrane antigen-1 in Myanmar isolates.

Background: Plasmodium falciparum apical membrane antigen-1 (PfAMA-1) is one of leading blood stage malaria vaccine candidates. However, genetic variation and antigenic diversity identified in global PfAMA-1 are major hurdles in the development of an effective vaccine based on this antigen. In this study, genetic structure and the effect of natural selection of PfAMA-1 among Myanmar P.

Therapeutic efficacy and artemisinin resistance in northern Myanmar: evidence from in vivo and molecular marker studies.

Background: In Myanmar, three types of artemisinin-based combination therapy (ACT) are recommended as first-line treatment of uncomplicated falciparum malaria: artemether-lumefantrine (AL), artesunate-mefloquine (AS + MQ), and dihydroartemisinin-piperaquine (DP). Resistance to both artemisinins and ACT partner drugs has been reported from the Greater Mekong Sub-region, and regular efficacy monitoring of the recommended ACT is conducted in Myanmar. This paper reports on results from studies to monitor the efficacy of the three forms of ACT in sentinel sites in northern Myanmar, and investigations of mutations in the Kelch13 (k13) propeller domain.

Comparison of the diagnostic performance of microscopic examination with nested polymerase chain reaction for optimum malaria diagnosis in Upper Myanmar.

Background: Accurate diagnosis of Plasmodium infection is crucial for prompt malaria treatment and surveillance. Microscopic examination has been widely applied as the gold standard for malaria diagnosis in most part of malaria endemic areas, but its diagnostic value has been questioned, particularly in submicroscopic malaria. In this study, the diagnostic performance of microscopic examination and nested polymerase chain reaction (PCR) was evaluated to establish optimal malaria diagnosis method in Myanmar.

A Worldwide Map of Plasmodium falciparum K13-Propeller Polymorphisms.

Background: Recent gains in reducing the global burden of malaria are threatened by the emergence of Plasmodium falciparum resistance to artemisinins. The discovery that mutations in portions of a P. falciparum gene encoding kelch (K13)-propeller domains are the major determinant of resistance has provided opportunities for monitoring such resistance on a global scale.

Spread of artemisinin-resistant Plasmodium falciparum in Myanmar: a cross-sectional survey of the K13 molecular marker.

Background: Emergence of artemisinin resistance in southeast Asia poses a serious threat to the global control of Plasmodium falciparum malaria. Discovery of the K13 marker has transformed approaches to the monitoring of artemisinin resistance, allowing introduction of molecular surveillance in remote areas through analysis of DNA. We aimed to assess the spread of artemisinin-resistant P falciparum in Myanmar by determining the relative prevalence of P falciparum parasites carrying K13-propeller mutations.

Preservation of wild isolates of human malaria parasites in wet ice and adaptation efficacy to in vitro culture.

Wild isolates of malaria parasites were preserved in wet ice for 2-12 days and cultivated by a candle jar method. In four isolates of Plasmodium falciparum collected from Myanmar and preserved for 12 days, all failed to grow. In 31 isolates preserved for 5-10 days, nine were transformed to young gametocytes, but 22 isolates grew well.

Genetic polymorphism and natural selection of Duffy binding protein of Plasmodium vivax Myanmar isolates.

Background: Plasmodium vivax Duffy binding protein (PvDBP) plays an essential role in erythrocyte invasion and a potential asexual blood stage vaccine candidate antigen against P. vivax. The polymorphic nature of PvDBP, particularly amino terminal cysteine-rich region (PvDBPII), represents a major impediment to the successful design of a protective vaccine against vivax malaria.

Comparison of the antibody responses to Plasmodium vivax and Plasmodium falciparum antigens in residents of Mandalay, Myanmar.

Background: The aim of this study was to investigate the profile of antibodies against several antigens of Plasmodium vivax and Plasmodium falciparum in Mandalay, Myanmar.

Methods: Malaria parasites were identified by microscopic examination. To test the antibodies against P.

Molecular cloning and expression of the VK247 circumsporozoite protein for serodiagnosis of variant form Plasmodium vivax.

Plasmodium vivax is classified into two serotypes, VK210 [the dominant form-GDRA(D/A)GQPA repeats] and VK247 [the variant form-ANGA(G/D)(N/D)QPG repeats], based on sequence variation of the repeat region of the circumsporozoite (CS) protein gene. Genomic DNA for the variant CS protein gene was obtained from field isolate strains in Myanmar. The repetitive region has highly 19 immunogenic repeats flanked by non-repeat stretches of amino acids.

Genetic polymorphism in pvmdr1 and pvcrt-o genes in relation to in vitro drug susceptibility of Plasmodium vivax isolates from malaria-endemic countries.

Treatment failure of chloroquine for Plasmodium vivax infection has increased in endemic countries. However, the molecular mechanisms for resistance and in vitro susceptibility of P. vivax to chloroquine remain elusive.

Mutations in the antifolate-resistance-associated genes dihydrofolate reductase and dihydropteroate synthase in Plasmodium vivax isolates from malaria-endemic countries.

Parasite dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) are known target enzymes of antifolate drugs used for the treatment and prophylaxis of persons with malaria. We sequenced the Plasmodium vivax dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps) genes to examine the prevalence and extent of point mutations in isolates from malaria-endemic countries. Double mutations (S58R and S117N) or quadruple mutations (F57L/I, S58R, T61M, and S117T) in the pvdhfr gene were found in isolates from Thailand (96.