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Background: Due to the low prevalence of clinical malaria of 1-2 % among pregnant women in Myanmar, little is known about its impact on mothers and newborns. Helminth and HIV co-infections may cause anaemia and other adverse health outcomes for both mother and child. This study assessed the prevalence of subclinical malaria and co-infections among pregnant women, and their association with adverse outcomes of pregnancy in the presence of infection. Methods: A prospective longitudinal study was conducted in 12 villages in two townships in Myanmar between 2013 to 2015. A total of 752 pregnant women, with mean age of 27 years, were enrolled and followed up once a month, until six weeks after the delivery. Results: About 84% of women were asymptomatic and 40% were primigravid at the time of enrolment. The prevalence of subclinical malaria as measured by nested PCR was 5.7% for either P. falciparum or P. vivax, with 2.7% prevalence of P. falciparum and 2.8% prevalence of P. vivax. Helminth infections were prevalent in 17% of women, and one woman with a HIV infection was found in our study. The burden of anemia was high, with an overall prevalence of 37% with or without helminth infection, 42% of the women were malaria positive and 43% had dual infections (both malaria and helminth). Only 11 abnormal pregnancy outcomes (7 stillbirth, 2 premature, 2 twins) were identified. Poisson regression showed that women in their first trimester had a 2.9 times higher rate of subclinical malaria compared to women in the third trimester (PR:2.9, 95%CI: 1.19, 7.31, p=0.019), women who were enrolled during the wet season were 2.5 times more likely to be malaria positive than the women enrolled in the dry season (PR: 2.5, 95%CI: 1.27, 4.88, p=0.008), and the malaria positivity rate decreased by 5% when increased in one year of woman’s age (PR:0.95, 95%CI: 0.91, 0.99, p=0.02). In the multivariable regression, the age of respondents was the only significant factor associated with subclinical malaria in pregnancy. Conclusions: The low prevalence of heterogenous subclinical malaria among pregnant women should not be neglected when targeting malaria elimination.

Background More details about human movement patterns are needed to evaluate relationships between daily travel and malaria risk at finer scales. A multiagent mobility simulation model was built to simulate the movements of villagers between home and their workplaces in 2 townships in Myanmar. Methods An agent-based model (ABM) was built to simulate daily travel to and from work based on responses to a travel survey. Key elements for the ABM were land cover, travel time, travel mode, occupation, malaria prevalence, and a detailed road network. Most visited network segments for different occupations and for malaria-positive cases were extracted and compared. Data from a separate survey were used to validate the simulation. Results Mobility characteristics for different occupation groups showed that while certain patterns were shared among some groups, there were also patterns that were unique to an occupation group. Forest workers were estimated to be the most mobile occupation group, and also had the highest potential malaria exposure associated with their daily travel in Ann Township. In Singu Township, forest workers were not the most mobile group; however, they were estimated to visit regions that had higher prevalence of malaria infection over other occupation groups. Conclusions Using an ABM to simulate daily travel generated mobility patterns for different occupation groups. These spatial patterns varied by occupation. Our simulation identified occupations at a higher risk of being exposed to malaria and where these exposures were more likely to occur.

Four single-arm, prospective, clinical studies of pyronaridine-artesunate efficacy in uncomplicated Plasmodium falciparum or Plasmodium vivax malaria were conducted in Myanmar between 2017 and 2019. Eligible subjects were aged at least 6 years, with microscopically confirmed P. falciparum (n = 196) or P. vivax mono-infection (n = 206). Patients received pyronaridine-artesunate once daily for 3 days with follow-up until day 42 for P. falciparum or day 28 for P. vivax. For the primary efficacy analysis, adequate clinical and parasitological response (ACPR) in the per-protocol population at day 42 for P. falciparum malaria was 100% (88/88; 95% CI: 95.9, 100) in northern Myanmar (Kachin State and northern Shan State), and 100% (101/101; 95% CI: 96.4, 100) in southern Myanmar (Tanintharyi Region and Kayin State). Plasmodium falciparum day-3 parasite clearance was observed for 96.9% (190/196) of patients. Mutations in the P. falciparum Kelch propeller domain (K13) were detected in 39.0% (69/177) of isolates: F446I (14.7% [26/177]), R561H (13.0% [23/177]), C580Y (10.2% [18/177]), and P574L (1.1% [2/177]). For P. vivax, the day-28 ACPR was 100% (104/104; 95% CI: 96.5, 100) in northern Myanmar and 100% (97/97; 95% CI: 96.3, 100) in southern Myanmar. Across both P. vivax studies, 100% (206/206) of patients had day-3 parasite clearance. There were no adverse events. Pyronaridine-artesunate had excellent efficacy in Myanmar against P. falciparum and P. vivax and was well tolerated. This study supports the inclusion of pyronaridine-artesunate in national malaria treatment guidelines for Myanmar.

The emergence of artemisinin-resistant Plasmodium falciparum 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 P. falciparum at three study sites in Rakhine, Shan, and Kachin states in Myanmar. Patients presenting with uncomplicated P. falciparum malaria were enrolled, treated, and followed up for 28 days for AL or 42 days for DP. Both AL and DP demonstrated good therapeutic efficacy at all three study sites. The 28-day cure rate for AL was > 96% across all study sites, and the 42-day cure rate for DP was 100%. Parasitemia on day 3 was detected in 0%, 3.3%, and 3.6% of participants treated with AL at the Rakhine, Shan, and Kachin sites, respectively. No participants treated with DP were parasitemic on day 3. No evidence of P. falciparum k13 mutations was found at the Rakhine study site. A high prevalence of k13 mutations associated with artemisinin resistance was observed at the Kachin and Shan state study sites. These results confirm that ACT efficacy has been resilient in therapeutic efficacy study (TES) sentinel sites in Myanmar, despite the presence at some sites of k13 mutations associated with resistance. Studies are ongoing to assess whether this resilience persists.

Background Achieving the elimination of soil-transmitted helminth (STH) infections requires a sufficient understanding of the current epidemiological status of STH endemicity. We aimed to examine the status of STH in Myanmar – a country with the eighth highest STH prevalence in the world, 10 years after instigation of the national deworming programme. Methods In August 2016 we screened for STH infections using Kato Katz (KK) microscopy and real-time PCR (qPCR) in schoolchildren from the Bago Region township of Phyu, a STH sentinel site in Myanmar. Ten schools were randomly selected, and one stool sample each from a total of 264 students was examined. Prevalence and intensity of infection were calculated for each STH. Results High prevalence of STH was identified in the study area with 78.8% of the schoolchildren infected with at least one STH by qPCR, and 33.3% by KK. The most prevalent STH was Trichuris trichiura, diagnosed by both KK (26.1%) and qPCR (67.1%), followed by Ascaris lumbricoides (15.5% KK; 54.9% qPCR). No hookworm infections were identified by KK; however, the qPCR analysis showed a high prevalence of Ancylostoma sp. infection (29.6%) with few Necator americanus (1.1%) infections. Conclusions Despite bi-annual deworming of schoolchildren in the fourth-grade and below, STH prevalence remains stubbornly high. These results informed the expansion of the Myanmar National STH control programme to include all school-aged children by the Ministry of Health and Sports in 2017, however further expansion to the whole community should be considered along with improving sanitation and hygiene measures. This would be augmented by rigorous monitoring and evaluation, including national prevalence surveys.

Background Screening malaria-specific antibody responses on protein microarrays can help identify immune factors that mediate protection against malaria infection, disease, and transmission, as well as markers of past exposure to both malaria parasites and mosquito vectors. Most malaria protein microarray work has used serum as the sample matrix, requiring prompt laboratory processing and a continuous cold chain, thus limiting applications in remote locations. Dried blood spots (DBS) pose minimal biohazard, do not require immediate laboratory processing, and are stable at room temperature for transport, making them potentially superior alternatives to serum. The goals of this study were to assess the viability of DBS as a source for antibody profiling and to use DBS to identify serological signatures of low-density Plasmodium falciparum infections in malaria-endemic regions of Myanmar. Methods Matched DBS and serum samples from a cross-sectional study in Ingapu Township, Myanmar were probed on protein microarrays populated with P. falciparum antigen fragments. Signal and trends in both sample matrices were compared. A case-control study was then performed using banked DBS samples from malaria-endemic regions of Myanmar, and a regularized logistic regression model was used to identify antibody signatures of ultrasensitive PCR-positive P. falciparum infections. Results Approximately 30% of serum IgG activity was recovered from DBS. Despite this loss of antibody activity, antigen and population trends were well-matched between the two sample matrices. Responses to 18 protein fragments were associated with the odds of asymptomatic P. falciparum infection, albeit with modest diagnostic characteristics (sensitivity 58%, specificity 85%, negative predictive value 88%, and positive predictive value 52%). Conclusions Malaria-specific antibody responses can be reliably detected, quantified, and analysed from DBS, opening the door to serological studies in populations where serum collection, transport, and storage would otherwise be impossible. While test characteristics of antibody signatures were insufficient for individual diagnosis, serological testing may be useful for identifying exposure to asymptomatic, low-density malaria infections, particularly if sero-surveillance strategies target individuals with low previous exposure as sentinels for population exposure.

The COVID-19 pandemic has highlighted the important role molecular surveillance plays in public health. Such capacity however is either weak or nonexistent in many low-income countries. This article outlines a 2-year effort to establish two high-throughput molecular surveillance laboratories in Myanmar for tracking asymptomatic and drug resistant Plasmodium falciparum malaria. The lessons learned from this endeavor may prove useful for others seeking to establish similar molecular surveillance capacity in other resource-limited settings.

Background Myanmar has similar agro-based ecology and environmental risks as others in the Greater Mekong sub-region leading to the broad array of helminthic infections. Basic health staff (BHS) from the public sector forms a key stakeholder group in deworming interventions. The study aimed to ascertain the prevalence and determinants of multiple species helminth infections to promote township-level integrated interventions. Methods A cross-sectional implementation research study in 2017 covered randomly selected 240 households in four villages of Shwegyin Township. Trained interviewers administered the pre-tested structured questionnaire to either the household head or the assigned person concerning their knowledge, perceptions, practices, food habits, and deworming experience. Concomitantly, the research team collected a single stool sample from each of 698 participants (age range of 8 months to 87 years) from 93% (224/240) of eligible households and examined by Kato-Katz smear microscopy. Eventually, 16 BHS joined the interactive dialogue session based on research evidence and knowledge translated for further validation. Results The estimated prevalence of at least one helminth infection was 24% [168/698; 95% CI 21.0–27.0]. Apart from the soil-transmitted helminths (14%), zoonotic helminths especially Taenia spp. (0.7%) and Schistosoma spp. (3%) were detected. Almost half of the seasonally mobile gold panning workers (12/25; 48%) and 46% of pre-school-age children had helminth infections. Community risk groups at riverside villages had significantly higher multiple species helminth infection than those from inland villages (AOR = 10.9; 95% CI 4.9–24.2). Gold panning workers had higher infection rates than other categories (AOR = 2.5; 95% CI 0.6–9.5) but not significant. In flood-prone areas, householders failed to follow the guidelines to construct/re-construct specific type of sanitary latrines and challenges remained in disseminating health messages for community engagement. The innovative ideas recapitulated by BHS included the integration of health talks during the sessions for small agricultural loans and to harness advocacy with water, sanitation, and hygiene interventions. Conclusions The emerging evidence of neglected zoonotic helminths required attention to introduce the periodic mopping-up and the “selective deworming plan” for vulnerable groups to cover the missed targets. Further multidisciplinary research to confirm the intermediate hosts and vectors of zoonotic helminths in the environment is essential for surveillance and response. Electronic supplementary material The online version of this article (10.1186/s41182-018-0133-6) contains supplementary material, which is available to authorized users.

Malaria incidence in Myanmar has significantly reduced over recent years, however, completeness and timeliness of incidence data remain a challenge. The first ever nationwide malaria infection and seroprevalence survey was conducted in Myanmar in 2015 to better understand malaria epidemiology and highlight gaps in Annual Parasite Index (API) data. The survey was a cross-sectional two-stage stratified cluster-randomised household survey conducted from July-October 2015. Blood samples were collected from household members for ultra-sensitive PCR and serology testing for P. falciparum and P. vivax. Data was gathered on demography and a priori risk factors of participants. Data was analysed nationally and within each of four domains defined by API data. Prevalence and seroprevalence of malaria were 0.74% and 16.01% nationwide, respectively. Prevalent infection was primarily asymptomatic P. vivax, while P. falciparum was predominant in serology. There was large heterogeneity between villages and by domain. At the township level, API showed moderate correlation with P. falciparum seroprevalence. Risk factors for infection included socioeconomic status, domain, and household ownership of nets. Three K13 P. falciparum mutants were found in highly prevalent villages. There results highlight high heterogeneity of both P. falciparum and P. vivax transmission between villages, accentuated by a large hidden reservoir of asymptomatic P. vivax infection not captured by incidence data, and representing challenges for malaria elimination. Village-level surveillance and stratification to guide interventions to suit local context and targeting of transmission foci with evidence of drug resistance would aid elimination efforts.

Summary 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. Genetic relatedness was assessed using microsatellite and single nucleotide polymorphism typing of flanking sequences around target genes. Findings 10 632 isolates were genotyped. A single long pfkelch Cys580Tyr haplotype (from −50 kb to +31·5 kb) conferring artemisinin resistance (PfPailin) now dominates across the eastern Greater Mekong subregion. Piperaquine resistance associated with pfplasmepsin2 gene amplification and mutations in pfcrt downstream of the Lys76Thr chloroquine resistance locus has also developed. On the Thailand–Myanmar border a different pfkelch Cys580Tyr lineage rose to high frequencies before it was eliminated. Elsewhere in Myanmar the Cys580Tyr allele remains widespread at low allele frequencies. Meanwhile a single artemisinin-resistant pfkelch Phe446Ile haplotype has spread across Myanmar. Despite intense use of dihydroartemisinin–piperaquine in Kayin state, eastern Myanmar, both in treatment and mass drug administrations, no selection of piperaquine resistance markers was observed. pfmdr1 amplification, a marker of resistance to mefloquine, remains at low prevalence across the entire region. Interpretation Artemisinin resistance in P falciparum is now prevalent across the Greater Mekong subregion. In the eastern Greater Mekong subregion a multidrug resistant P falciparum lineage (PfPailin) dominates. In Myanmar a long pfkelch Phe446Ile haplotype has spread widely but, by contrast with the eastern Greater Mekong subregion, there is no indication of artemisinin combination therapy (ACT) partner drug resistance from genotyping known markers, and no evidence of spread of ACT resistant P falciparum from the east to the west. There is still a window of opportunity to prevent global spread of ACT resistance. Funding Thailand Science Research and Innovation, Initiative 5%, Expertise France, Wellcome Trust.

Despite progress toward malaria elimination in the Greater Mekong Subregion, challenges remain owing to the emergence of drug resistance and the persistence of focal transmission reservoirs. Malaria transmission foci in Myanmar are heterogeneous and complex, and many remaining infections are clinically silent, rendering them invisible to routine monitoring. The goal of this research is to define criteria for easy‐to‐implement methodologies, not reliant on routine monitoring, that can increase the efficiency of targeted malaria elimination strategies. Studies have shown relationships between malaria risk and land cover and land use (LCLU), which can be mapped using remote sensing methodologies. Here we aim to explain malaria risk as a function of LCLU for five rural villages in Myanmar's Rakhine State. Malaria prevalence and incidence data were analyzed through logistic regression with a land use survey of ~1,000 participants and a 30‐m land cover map. Malaria prevalence per village ranged from 5% to 20% with the overwhelming majority of cases being subclinical. Villages with high forest cover were associated with increased risk of malaria, even for villagers who did not report visits to forests. Villagers living near croplands experienced decreased malaria risk unless they were directly engaged in farm work. Finally, land cover change (specifically, natural forest loss) appeared to be a substantial contributor to malaria risk in the region, although this was not confirmed through sensitivity analyses. Overall, this study demonstrates that remotely sensed data contextualized with field survey data can be used to inform critical targeting strategies in support of malaria elimination., Key Points Villages in Ann Township, Myanmar, exhibiting high forest cover are strongly associated with increased risk of malariaAnn Township, Myanmar, villagers living in villages where croplands are the dominant land cover type experience decreased malaria riskRemote sensing offers a means to locate LCLU areas associated with high malaria risk to allow for more efficient targeted interventions

Four single-arm, prospective, clinical studies of pyronaridine–artesunate efficacy in uncomplicated Plasmodium falciparum or Plasmodium vivax malaria were conducted in Myanmar between 2017 and 2019. Eligible subjects were aged at least 6 years, with microscopically confirmed P. falciparum (n = 196) or P. vivax mono-infection (n = 206). Patients received pyronaridine–artesunate once daily for 3 days with follow-up until day 42 for P. falciparum or day 28 for P. vivax. For the primary efficacy analysis, adequate clinical and parasitological response (ACPR) in the per-protocol population at day 42 for P. falciparum malaria was 100% (88/88; 95% CI: 95.9, 100) in northern Myanmar (Kachin State and northern Shan State), and 100% (101/101; 95% CI: 96.4, 100) in southern Myanmar (Tanintharyi Region and Kayin State). Plasmodium falciparum day-3 parasite clearance was observed for 96.9% (190/196) of patients. Mutations in the P. falciparum Kelch propeller domain (K13) were detected in 39.0% (69/177) of isolates: F446I (14.7% [26/177]), R561H (13.0% [23/177]), C580Y (10.2% [18/177]), and P574L (1.1% [2/177]). For P. vivax, the day-28 ACPR was 100% (104/104; 95% CI: 96.5, 100) in northern Myanmar and 100% (97/97; 95% CI: 96.3, 100) in southern Myanmar. Across both P. vivax studies, 100% (206/206) of patients had day-3 parasite clearance. There were no adverse events. Pyronaridine–artesunate had excellent efficacy in Myanmar against P. falciparum and P. vivax and was well tolerated. This study supports the inclusion of pyronaridine–artesunate in national malaria treatment guidelines for Myanmar.

Background The most commonly used diagnostic tool for soil-transmitted helminths (STH) is the Kato-Katz (KK) thick smear technique. However, numerous studies have suggested that the sensitivity of KK can be problematic, especially in low prevalence and low intensity settings. An emerging alternative is quantitative polymerase chain reaction (qPCR). Methods In this study, both KK and qPCR were conducted on stool samples from 648 participants in an STH epidemiology study conducted in the delta region of Myanmar in June 2016. Results Prevalence of any STH was 20.68% by KK and 45.06% by qPCR. Prevalence of each individual STH was also higher by qPCR than KK, the biggest difference was for hookworm with an approximately 4-fold increase between the two diagnostic techniques. Prevalence of Ancylostoma ceylanicum, a parasite predominately found in dogs, was 4.63%, indicating that there is the possibility of zoonotic transmission in the study setting. In individuals with moderate to high intensity infections there is evidence for a linear relationship between eggs per gram (EPG) of faeces, derived from KK, and DNA copy number, derived from qPCR which is particularly strong for Ascaris lumbricoides. Conclusions The use of qPCR in low prevalence settings is important to accurately assess the epidemiological situation and plan control strategies for the ‘end game’. However, more work is required to accurately assess STH intensity from qPCR results and to reduce the cost of qPCR so that is widely accessible in STH endemic countries.

The emergence of artemisinin-resistant Plasmodium falciparum 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 P. falciparum at three study sites in Rakhine, Shan, and Kachin states in Myanmar. Patients presenting with uncomplicated P. falciparum malaria were enrolled, treated, and followed up for 28 days for AL or 42 days for DP. Both AL and DP demonstrated good therapeutic efficacy at all three study sites. The 28-day cure rate for AL was > 96% across all study sites, and the 42-day cure rate for DP was 100%. Parasitemia on day 3 was detected in 0%, 3.3%, and 3.6% of participants treated with AL at the Rakhine, Shan, and Kachin sites, respectively. No participants treated with DP were parasitemic on day 3. No evidence of P. falciparum k13 mutations was found at the Rakhine study site. A high prevalence of k13 mutations associated with artemisinin resistance was observed at the Kachin and Shan state study sites. These results confirm that ACT efficacy has been resilient in therapeutic efficacy study (TES) sentinel sites in Myanmar, despite the presence at some sites of k13 mutations associated with resistance. Studies are ongoing to assess whether this resilience persists.

Objectives To determine the distribution of Plasmodium (P) species including Plasmodium knowlesi and to compare the specificity and sensitivity of microscopy with nested PCR in malaria diagnosis. Methods The study was conducted in Kawthaung, southern Myanmar. Ninety clinically suspected malaria patients were screened for malaria by Giemsa stained microscopy and confirmed by nested PCR. Results Among the participants, 57 (63.3%) were positive and 33 (36.7%) were negative by microscopy. Of positive samples, 39 (68.4%) were Plasmodium falciparum, 17 (29.8%) Plasmodium vivax and 1 (1.8%) Plasmodium malariae, whereas 59-amplified by PCR were 40 (67.8%), 18 (30.5%) and 1 (1.7%) respectively. PCR amplified 2 microscopy negative samples. Two samples of P. falciparum detected by microscopy were amplified as P. vivax and vice versa. All samples were negative for Plasmodium ovale, P. knowlesi and mixed infections. Microscopy had a very good measure of agreement (κ = 0.95) compared to nested PCR. Sensitivity and specificity of microscopy for diagnosis of P. falciparum were 92.5% (95% CI: 79.6–98.4) and 96.0% (95% CI: 86.3–99.5) respectively, whereas for P. vivax were 83.3% (95% CI: 58.6–96.4) and 97.2% (95% CI: 90.3–99.7). Conclusions P. knowlesi was not detected by both microscopy and PCR. Giemsa stained microscopy can still be applied as primary method for malaria diagnosis and is considered as gold standard. As to the lower sensitivity of microscopy for vivax malaria, those with previous history of malaria and relapse cases should be diagnosed by RDT or PCR combined with microscopy. Inaccuracy of species diagnosis highlighted the requirement of training and refresher courses for microscopists.

Background Alongside monitoring of the disease burden, the successful move towards malaria elimination relies on the readiness of the health care delivery system. However, there is a lack of evidence in the gap of existing National Guidelines and access to low dose primaquine in real practice under varying degrees of antimalarial resistance in the pre-elimination phase in Myanmar. Therefore, this study addressed the essential information from the service delivery points (SDPs) of public and private sectors on the availability and the use of primaquine in both supply and demand side. Concomitantly, the study aimed to underscore challenges in health system infrastructure to promote the sustained flow in rolling out primaquine in line with National Guidelines for malaria elimination. Methods A cross-sectional study conducted from September 2017 to February 2018 included six townships of three states/regions. The team used an observation checklist for documenting primaquine supplies at SDPs. Semi-structured interviews, key informant, and in-depth interviews focused both public and private sectors including staff from the Vector-Borne Diseases Control (VBDC) teams in each state/region and rural health centers (n = 25), those from the non-governmental organizations (NGOs), general practitioners and drug sellers (n = 11), and recently infected malaria patients (n = 11). Triangulation of quantitative and qualitative data provided meaningful interpretations. Results Public sector staff reported an adequate stock of primaquine, but it was unavailable at the general practitioners’ clinics without any connection to NGOs and also at the unlicensed drug shops. Health care providers of the public sector experienced challenges in poor compliance of malaria patients to primaquine treatment in conjunction with an artemisinin-based combination therapy, loss-to-follow-ups especially in conflict areas, and delays in timely substitution of new batches of primaquine. Respondents from the private sector demanded for the refresher training course on updated antimalarial treatment guidelines. Conclusion Monitoring compliance and safety of primaquine treatment was found as a barrier especially among mobile migrant workers and those who were in conflict areas. An alternative strategy by the NMCP could enable to prevent the underutilization of primaquine in vivax malaria to reach the malaria elimination targets.

Background The genetic diversity of malaria parasites reflects the complexity and size of the parasite populations. This study was designed to explore the genetic diversity of Plasmodium falciparum populations collected from two southeastern areas (Shwekyin and Myawaddy bordering Thailand) and one western area (Kyauktaw bordering Bangladesh) of Myanmar. Methods A total of 267 blood samples collected from patients with acute P. falciparum infections during 2009 and 2010 were used for genotyping at the merozoite surface protein 1 (Msp1), Msp2 and glutamate-rich protein (Glurp) loci. Results One hundred and eighty four samples were successfully genotyped at three genes. The allelic distributions of the three genes were all significantly different among three areas. MAD20 and 3D7 were the most prevalent alleles in three areas for Msp1 and Msp2, respectively. The Glurp allele with a bin size of 700–750 bp was the most prevalent both in Shwekyin and Myawaddy, whereas two alleles with bin sizes of 800–850 bp and 900–1000 bp were the most prevalent in the western site Kyauktaw. Overall, 73.91% of samples contained multiclonal infections, resulting in a mean multiplicity of infection (MOI) of 1.94. Interestingly, the MOI level presented a rising trend with the order of Myawaddy, Kyauktaw and Shwekyin, which also paralleled with the increasing frequencies of Msp1 RO33 and Msp2 FC27 200–250 bp alleles. Msp1 and Msp2 genes displayed higher levels of diversity and higher MOI rates than Glurp. PCR revealed four samples (two from Shwekyin and two from Myawaddy) with mixed infections of P. falciparum and P. vivax. Conclusions This study genotyped parasite clinical samples from two southeast regions and one western state of Myanmar at the Msp1, Msp2 and Glurp loci, which revealed high levels of genetic diversity and mixed-strain infections of P. falciparum populations at these sites. The results indicated that malaria transmission intensity in these regions remained high and more strengthened control efforts are needed. The genotypic data provided baseline information for monitoring the impacts of malaria elimination efforts in the region. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2254-x) contains supplementary material, which is available to authorized users.

Background One of the major challenges for control and elimination of malaria is ongoing spread and emergence of drug resistance. While epidemiology and surveillance of the drug resistance in falciparum malaria is being explored globally, there are few studies on drug resistance vivax malaria. Methods To assess the spread of drug-resistant vivax malaria in Myanmar, a multisite, prospective, longitudinal study with retrospective analysis of previous therapeutic efficacy studies, was conducted. A total of 906 from nine study sites were included in retrospective analysis and 208 from three study sites in prospective study. Uncomplicated vivax mono-infected patients were recruited and monitored with longitudinal follow-up until day 28 after treatment with chloroquine. Amplification and sequence analysis of molecular markers, such as mutations in pvcrt-O, pvmdr1, pvdhps and pvdhfr, were done in day-0 samples in prospective study. Results Clinical failure cases were found only in Kawthaung, southern Myanmar and western Myanmar sites within 2009–2016. Chloroquine resistance markers, pvcrt-O ‘AAG’ insertion and pvmdr1 mutation (Y976F) showed higher mutant rate in southern and central Myanmar than western site: 66.7, 72.7 vs 48.3% and 26.7, 17.0 vs 1.7%, respectively. A similar pattern of significantly higher mutant rate of antifolate resistance markers, pvdhps (S382A, K512M, A553G) and pvdhfr (F57L/I, S58R, T61M, S117T/N) were noted. Conclusions Although clinical failure rate was low, widespread distribution of chloroquine and antifolate resistance molecular makers alert to the emergence and spread of drug resistance vivax malaria in Myanmar. Proper strategy and action plan to eliminate and contain the resistant strain strengthened together with clinical and molecular surveillance on drug resistance vivax is recommended. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1770-7) contains supplementary material, which is available to authorized users.

Background Highly sensitive, scalable diagnostic methods are needed to guide malaria elimination interventions. While traditional microscopy and rapid diagnostic tests (RDTs) are suitable for the diagnosis of symptomatic malaria infection, more sensitive tests are needed to screen for low-density, asymptomatic infections that are targeted by interventions aiming to eliminate the entire reservoir of malaria infection in humans. Methods A reverse transcription polymerase chain reaction (RT- PCR) was developed for multiplexed detection of the 18S ribosomal RNA gene and ribosomal RNA of Plasmodium falciparum and Plasmodium vivax. Simulated field samples stored for 14 days with sample preservation buffer were used to assess the analytical sensitivity and specificity. Additionally, 1750 field samples from Southeastern Myanmar were tested both by RDT and ultrasensitive RT-PCR. Results Limits of detection (LoD) were determined under simulated field conditions. When 0.3 mL blood samples were stored for 14 days at 28 °C and 80 % humidity, the LoD was less than 16 parasites/mL for P. falciparum and 19.7 copies/µL for P. vivax (using a plasmid surrogate), about 10,000-fold lower than RDTs. Of the 1739 samples successfully evaluated by both ultrasensitive RT-PCR and RDT, only two were RDT positive while 24 were positive for P. falciparum, 108 were positive for P. vivax, and 127 were positive for either P. vivax and/or P. falciparum using ultrasensitive RT-PCR. Conclusions This ultrasensitive RT-PCR method is a robust, field-tested screening method that is vastly more sensitive than RDTs. Further optimization may result in a truly scalable tool suitable for widespread surveillance of low-level asymptomatic P. falciparum and P. vivax parasitaemia. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1038-z) contains supplementary material, which is available to authorized users.

A total of 60 HIV infected patients complaining of dry cough for at least two weeks and attending the Out-patient Department of the Specialist Hospital, Waibargi, were screened for Pneumocystis carinii. Induced sputum samples were examined with Giemsa and Gomori silver methenamine stains. P. carinii were detected in 18 patients (30%) with silver stain and 13 patients (21.7%) with Giemsa stain. The sensitivity and specificity of the Giemsa stain were 72.2% and 95.2%, respectively. The range of CD4 counts in P. carinii-positive patients was found to be 0-562/microl, and the mean CD4 count was 132.3/microl. Out of 18 P. carinii-positive cases, CD4 counts of 15 cases (83.3%) were200/microl and those of 3 cases were200/microl. Clinically, P. carinii-positive cases were associated with fever in 55.5%, with tightness of the chest in 38.9%, and with cyanosis and tightness of the chest in 11.1%. Co-infection with tuberculosis was found in 16.7%. Anti-pneumocystic prophylaxis is recommended for those patients with a CD4 count200/microl. Giemsa staining could be used as an alternative diagnostic method for detecting P. carinii. This study documented the existing prevalence of P. carinii among HIV-infected Myanmar patients.