Clinical and molecular surveillance of artemisinin resistant falciparum malaria in Myanmar (2009-2013).

BACKGROUND: Emergence of artemisinin-resistant malaria in Southeast Asian countries threatens the global control of malaria. Although K13 kelch propeller has been assessed for artemisinin resistance molecular marker, most of the mutations need to be validated. In this study, artemisinin resistance was assessed by clinical and molecular analysis, including k13 and recently reported markers, pfarps10, pffd and pfmdr2. METHODS: A prospective cohort study in 1160 uncomplicated falciparum patients was conducted after treatment with artemisinin-based combination therapy (ACT), in 6 sentinel sites in Myanmar from 2009 to 2013. Therapeutic efficacy of ACT was assessed by longitudinal follow ups. Molecular markers analysis was done on all available day 0 samples. RESULTS: True recrudescence treatment failures cases and day 3 parasite positivity were detected at only the southern Myanmar sites. Day 3 positive and k13 mutants with higher prevalence of underlying genetic foci predisposing to become k13 mutant were detected only in southern Myanmar since 2009 and comparatively fewer mutations of pfarps10, pffd, and pfmdr2 were observed in western Myanmar. K13 mutations, V127M of pfarps10, D193Y of pffd, and T448I of pfmdr2 were significantly associated with day 3 positivity (OR: 6.48, 3.88, 2.88, and 2.52, respectively). CONCLUSIONS: Apart from k13, pfarps10, pffd and pfmdr2 are also useful for molecular surveillance of artemisinin resistance especially where k13 mutation has not been reported. Appropriate action to eliminate the resistant parasites and surveillance on artemisinin resistance should be strengthened in Myanmar. Trial registration This study was registered with ClinicalTrials.gov, identifier NCT02792816.

Molecular assessment of artemisinin resistance markers, polymorphisms in the k13 propeller, and a multidrug-resistance gene in the eastern and western border areas of Myanmar.

BACKGROUND: As K13 propeller mutations have been recently reported to serve as molecular markers, assessment of K13 propeller polymorphisms in multidrug-resistant gene in isolates from Myanmar, especially the eastern and western border areas, is crucial if we are to understand the spread of artemisinin resistance. METHODS: A 3-day surveillance study was conducted in the eastern and western border areas in Myanmar, and K13 propeller and Plasmodium falciparum multidrug resistance-associated protein 1 (pfmrp1) mutations were analyzed. RESULTS: Among the 1761 suspected malaria cases screened, a total of 42 uncomplicated falciparum cases from the eastern border and 49 from the western border were subjected to 3 days of surveillance after artemether-lumefantrine treatment. No parasitemic case showing positivity on day 3 was noted from the western border, but 26.2% (11/42) of cases were positive in the eastern border. Although we found no marked difference in the prevalence of the pfmrp1 mutation in the eastern and western borders (36% vs 31%, respectively), K13 mutations were more frequent in the eastern border area (where the 3-day persistent cases were detected; 48% vs 14%). C580Y, M476I, A481V, N458Y, R539T, and R516Y accounted for 68.9% of all K13 mutations significantly associated with day 3 parasitaemia. CONCLUSIONS: The K13 mutations were significantly associated with day 3 parasitaemia, emphasizing the importance of K13 surveillance. The low prevalence of K13 mutations and the absence of day 3 parasitaemic cases indicate that artemisinin resistance may not have spread to the western Myanmar border region. Although analysis of multiple K13 mutations is challenging, it should be done at various sentinel sites in Myanmar.

Evaluation of the behaviour change communication and community mobilization activities in Myanmar artemisinin resistance containment zones.

BACKGROUND: Behaviour change communication (BCC) can improve malaria prevention and treatment behaviour. As a one of the activities under Myanmar Artemisinin Resistance Containment (MARC) programme, BCC have been conducting. This study aimed to evaluate the effectiveness of the behaviour change communication and community mobilization activities in MARC zones in Myanmar. METHODS: A cross sectional descriptive survey was conducted in randomly selected 16 townships in Tier I and II areas of MARC zones by quantitative and qualitative approaches. RESULTS: In 832 households resided by 4664 people, there were 3797 bed nets. Around 54% were untreated while 45.6% were insecticide-treated nets (ITN) and 36.2% were long-lasting insecticide-treated nets (LLINs). Proportion of households with at least one ITN was 625 (75.12%), proportion of households with at least one ITN for every two peoples was 487 (58.53%), and proportion of existing ITNs used in previous night was 1225 (70.65%) respectively. Nearly 23% of households had old nets while 52% had new and unused extra bed nets reflecting the adequacy. Interestingly, 38% could not mention the benefit of the use of ITN/LLINs. Although 88.2% knew the disease "malaria", 11.9% could not be able to mention the symptoms. More than 80% provided correct responses that mosquito bite can cause malaria while only 36.9% could mention the blood test for malaria diagnosis. Only 36.6% received malaria information within previous year but nearly 15% could not recognize it. Mostly, 80% of fever episodes were treated at rural health centers (38.24%) followed by drug shops (17.65%) and private clinics (16.18%) respectively. CONCLUSIONS: Efforts should focus on correcting misconceptions about malaria transmission, prevention and universal use of ITN/LLINs. Although BCC activities have been documented, it is still necessary to intensify community mobilization through all accessible multiple channels in MARC areas.

Comparison of microscopy, nested-PCR, and Real-Time-PCR assays using high-throughput screening of pooled samples for diagnosis of malaria in asymptomatic carriers from areas of endemicity in Myanmar.

Asymptomatic infection is an important obstacle for controlling disease in countries where malaria is endemic. Because asymptomatic carriers do not seek treatment for their infections, they can have high levels of gametocytes and constitute a reservoir available for new infection. We employed a sample pooling/PCR-based molecular detection strategy for screening malaria infection in residents from areas of Myanmar where malaria is endemic. Blood samples (n = 1,552) were collected from residents in three areas of malaria endemicity (Kayin State, Bago, and Tanintharyi regions) of Myanmar. Two nested PCR and real-time PCR assays showed that asymptomatic infection was detected in about 1.0% to 9.4% of residents from the surveyed areas. The sensitivities of the two nested PCR and real-time PCR techniques were higher than that of microscopy examination (sensitivity, 100% versus 26.4%; kappa values, 0.2 to 0.5). Among the three regions, parasite-positive samples were highly detected in subjects from the Bago and Tanintharyi regions. Active surveillance of residents from regions of intense malaria transmission would reduce the risk of morbidity and mitigate transmission to the population in these areas of endemicity. Our data demonstrate that PCR-based molecular techniques are more efficient than microscopy for nationwide surveillance of malaria in countries where malaria is endemic.