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O'Flaherty K, Oo WH, Zaloumis SG, Cutts JC, Aung KZ, Thein MM, Drew DR, Razook Z, Barry AE, Parischa N, Zaw NN, Thu HK, Thi A, Htay WYM, Soe AP, Simpson JA, Beeson JG, Agius PA, Fowkes FJI. Community-based molecular and serological surveillance of subclinical malaria in Myanmar. BMC Med 2021; 19:121. [PMID: 34044836 PMCID: PMC8161608 DOI: 10.1186/s12916-021-01993-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/27/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND In the Greater Mekong Subregion (GMS), current malaria surveillance strategies rely on a network of village health volunteers (VHVs) reporting the results of rapid diagnostic tests (RDTs), known to miss many asymptomatic infections. Integration of more sensitive diagnostic molecular and serological measures into the VHV network may improve surveillance of residual malaria transmission in hard-to-reach areas in the region and inform targeted interventions and elimination responses. However, data on residual malaria transmission that would be captured by these measures in the VHV-led testing and treatment surveillance network in the GMS is unknown. METHODS A total of 114 VHVs were trained to collect dried blood spots from villagers undergoing routine RDTs as part of VHV-led active and passive case detection from April 2015 to June 2016. Samples were subjected to molecular testing (quantitative polymerase chain reaction [qPCR]) to determine Plasmodium falciparum and P. vivax infection and serological testing (against P. falciparum and P. vivax antigens) to determine exposure to P. falciparum and P. vivax. RESULTS Over 15 months, 114 VHVs performed 32,194 RDTs and collected samples for molecular (n = 13,157) and serological (n = 14,128) testing. The prevalence of molecular-detectable P. falciparum and P. vivax infection was 3.2% compared to the 0.16% prevalence of Plasmodium spp. by RDT, highlighting the large burden of infections undetected by standard surveillance. Peaks in anti-P. falciparum, but not P. vivax, merozoite IgG seroprevalence coincided with seasonal P. falciparum transmission peaks, even in those with no molecularly detectable parasites. At the individual level, antibody seropositivity was associated with reduced odds of contemporaneous P. falciparum (OR for PfCSP 0.51 [95%CI 0.35, 0.76], p = 0.001, PfAMA1 0.70 [95%CI 0.52, 0.93], p = 0.01, and PfMSP2 0.81 [95%CI 0.61, 1.08], p = 0.15), but not P. vivax infection (OR PvAMA1 1.02 [95%CI 0.73, 1.43], p = 0.89) indicating a potential role of immunity in protection against molecular-detectable P. falciparum parasitaemia. CONCLUSIONS We demonstrated that integration and implementation of sample collection for molecular and serological surveillance into networks of VHV servicing hard-to-reach populations in the GMS is feasible, can capture significant levels of ongoing undetected seasonal malaria transmission and has the potential to supplement current routine RDT testing. Improving malaria surveillance by advancing the integration of molecular and serological techniques, through centralised testing approaches or novel point-of-contact tests, will advance progress, and tracking, towards malaria elimination goals in the GMS.
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Affiliation(s)
- Katherine O'Flaherty
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Win Han Oo
- Burnet Institute Myanmar, Yangon, Myanmar
| | - Sophie G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Julia C Cutts
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia.,Department of Medicine, University of Melbourne, Melbourne, Australia
| | | | | | - Damien R Drew
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Zahra Razook
- School of Medicine, Deakin University, Geelong, Australia
| | - Alyssa E Barry
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia.,Department of Medicine, University of Melbourne, Melbourne, Australia.,School of Medicine, Deakin University, Geelong, Australia
| | - Naanki Parischa
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | | | | | - Aung Thi
- Department of Public Health, Myanmar Ministry of Health, Nay Pyi Taw, Myanmar
| | | | | | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia.,Department of Medicine, University of Melbourne, Melbourne, Australia.,Department of Microbiology and Central Clinical School, Monash University, Melbourne, Australia
| | - Paul A Agius
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia.,Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia.,Judith Lumley Centre, La Trobe University, Melbourne, Australia
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia. .,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia. .,Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia. .,Department of Infectious Diseases, Monash University, Melbourne, Australia.
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Agius PA, Cutts JC, Han Oo W, Thi A, O'Flaherty K, Zayar Aung K, Kyaw Thu H, Poe Aung P, Mon Thein M, Nyi Zaw N, Yan Min Htay W, Paing Soe A, Razook Z, Barry AE, Htike W, Devine A, Simpson JA, Crabb BS, Beeson JG, Pasricha N, Fowkes FJI. Evaluation of the effectiveness of topical repellent distributed by village health volunteer networks against Plasmodium spp. infection in Myanmar: A stepped-wedge cluster randomised trial. PLoS Med 2020; 17:e1003177. [PMID: 32817632 PMCID: PMC7444540 DOI: 10.1371/journal.pmed.1003177] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/29/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The World Health Organization has yet to endorse deployment of topical repellents for malaria prevention as part of public health campaigns. We aimed to quantify the effectiveness of repellent distributed by the village health volunteer (VHV) network in the Greater Mekong Subregion (GMS) in reducing malaria in order to advance regional malaria elimination. METHODS AND FINDINGS Between April 2015 and June 2016, a 15-month stepped-wedge cluster randomised trial was conducted in 116 villages in Myanmar (stepped monthly in blocks) to test the effectiveness of 12% N,N-diethylbenzamide w/w cream distributed by VHVs, on Plasmodium spp. infection. The median age of participants was 18 years, approximately half were female, and the majority were either village residents (46%) or forest dwellers (40%). No adverse events were reported during the study. Generalised linear mixed modelling estimated the effect of repellent on infection detected by rapid diagnostic test (RDT) (primary outcome) and polymerase chain reaction (PCR) (secondary outcome). Overall Plasmodium infection detected by RDT was low (0.16%; 50/32,194), but infection detected by PCR was higher (3%; 419/13,157). There was no significant protection against RDT-detectable infection (adjusted odds ratio [AOR] = 0.25, 95% CI 0.004-15.2, p = 0.512). In Plasmodium-species-specific analyses, repellent protected against PCR-detectable P. falciparum (adjusted relative risk ratio [ARRR] = 0.67, 95% CI 0.47-0.95, p = 0.026), but not P. vivax infection (ARRR = 1.41, 95% CI 0.80-2.47, p = 0.233). Repellent effects were similar when delayed effects were modelled, across risk groups, and regardless of village-level and temporal heterogeneity in malaria prevalence. The incremental cost-effectiveness ratio was US$256 per PCR-detectable infection averted. Study limitations were a lower than expected Plasmodium spp. infection rate and potential geographic dilution of the intervention. CONCLUSIONS In this study, we observed apparent protection against new infections associated with the large-scale distribution of repellent by VHVs. Incorporation of repellent into national strategies, particularly in areas where bed nets are less effective, may contribute to the interruption of malaria transmission. Further studies are warranted across different transmission settings and populations, from the GMS and beyond, to inform WHO public health policy on the deployment of topical repellents for malaria prevention. TRIAL REGISTRATION Australian and New Zealand Clinical Trials Registry (ACTRN12616001434482).
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Affiliation(s)
- Paul A Agius
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Julia C Cutts
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Win Han Oo
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Aung Thi
- Department of Public Health, Myanmar Ministry of Health and Sports, Nay Pyi Taw, Myanmar
| | - Katherine O'Flaherty
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Htin Kyaw Thu
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Poe Poe Aung
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Myat Mon Thein
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Nyi Nyi Zaw
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | | | - Aung Paing Soe
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Zahra Razook
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - Alyssa E Barry
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.,Global Health Division, Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Win Htike
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar
| | - Angela Devine
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia.,Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | | | - James G Beeson
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar.,Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia.,Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | | | - Freya J I Fowkes
- Burnet Institute, Victoria, Australia, and Yangon, Myanmar.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
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Mhamilawa LE, Ngasala B, Morris U, Kitabi EN, Barnes R, Soe AP, Mmbando BP, Björkman A, Mårtensson A. Parasite clearance, cure rate, post-treatment prophylaxis and safety of standard 3-day versus an extended 6-day treatment of artemether-lumefantrine and a single low-dose primaquine for uncomplicated Plasmodium falciparum malaria in Bagamoyo district, Tanzania: a randomized controlled trial. Malar J 2020; 19:216. [PMID: 32576258 PMCID: PMC7310382 DOI: 10.1186/s12936-020-03287-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 06/12/2020] [Indexed: 11/19/2022] Open
Abstract
Background Artemisinin-based combination therapy (ACT) resistant Plasmodium falciparum represents an increasing threat to Africa. Extended ACT regimens from standard 3 to 6 days may represent a means to prevent its development and potential spread in Africa. Methods Standard 3-day treatment with artemether–lumefantrine (control) was compared to extended 6-day treatment and single low-dose primaquine (intervention); in a randomized controlled, parallel group, superiority clinical trial of patients aged 1–65 years with microscopy confirmed uncomplicated P. falciparum malaria, enrolled in Bagamoyo district, Tanzania. The study evaluated parasite clearance, including proportion of PCR detectable P. falciparum on days 5 and 7 (primary endpoint), cure rate, post-treatment prophylaxis, safety and tolerability. Clinical, and laboratory assessments, including ECG were conducted during 42 days of follow-up. Blood samples were collected for parasite detection (by microscopy and PCR), molecular genotyping and pharmacokinetic analyses. Kaplan–Meier survival analyses were done for both parasite clearance and recurrence. Results A total of 280 patients were enrolled, 141 and 139 in the control and intervention arm, respectively, of whom 121 completed 42 days follow-up in each arm. There was no difference in proportion of PCR positivity across the arms at day 5 (80/130 (61.5%) vs 89/134 (66.4%), p = 0.44), or day 7 (71/129 (55.0%) vs 70/134 (52.2%), p = 0.71). Day 42 microscopy determined cure rates (PCR adjusted) were 97.4% (100/103) and 98.3% (110/112), p = 0.65, in the control and intervention arm, respectively. Microscopy determined crude recurrent parasitaemia during follow-up was 21/121 (17.4%) in the control and 14/121 (11.6%) in the intervention arm, p = 0.20, and it took 34 days and 42 days in the respective arms for 90% of the patients to remain without recurrent parasitaemia. Lumefantrine exposure was significantly higher in intervention arm from D3 to D42, but cardiac, biochemical and haematological safety was high and similar in both arms. Conclusion Extended 6-day artemether–lumefantrine treatment and a single low-dose of primaquine was not superior to standard 3-day treatment for ACT sensitive P. falciparum infections but, importantly, equally efficacious and safe. Thus, extended artemether–lumefantrine treatment may be considered as a future treatment regimen for ACT resistant P. falciparum, to prolong the therapeutic lifespan of ACT in Africa. Trial registration ClinicalTrials.gov, NCT03241901. Registered July 27, 2017 https://clinicaltrials.gov/show/NCT03241901
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Affiliation(s)
- Lwidiko E Mhamilawa
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden. .,Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
| | - Billy Ngasala
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden.,Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Eliford Ngaimisi Kitabi
- Office of Clinical Pharmacology, Division of Pharmacometrics, Food and Drugs Administration, Silver Spring, MD, USA
| | - Rory Barnes
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Aung Paing Soe
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden.,Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Bruno P Mmbando
- Tanga Centre, National Institute for Medical Research, Tanga, Tanzania
| | - Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
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