Community-based molecular and serological surveillance of subclinical malaria in Myanmar

BMC Medicine

Nyi Nyi Zaw¹  Myat Mon Thein¹  Wai Yan Min Htay¹  Htin Kyaw Thu¹  Win Han Oo¹  Aung Paing Soe¹  Kyaw Zayar Aung¹  Damien R. Drew²  Naanki Parischa²  Katherine O’Flaherty³  Freya J. I. Fowkes⁴  Paul A. Agius⁵  Julia C. Cutts⁶  James G. Beeson⁷  Alyssa E. Barry⁸  Julie A. Simpson⁹  Sophie G. Zaloumis⁹  Aung Thi^1,10  Zahra Razook^1,11 

[1] Burnet Institute Myanmar, Yangon, Myanmar;Burnet Institute for Medical Research and Public Health, Melbourne, Australia;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;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;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;Burnet Institute for Medical Research and Public Health, Melbourne, Australia;Department of Medicine, University of Melbourne, Melbourne, Australia;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;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;Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia;Department of Public Health, Myanmar Ministry of Health, Nay Pyi Taw, Myanmar;School of Medicine, Deakin University, Geelong, Australia;

关键词: Malaria;    Plasmodium;    Surveillance;    Epidemiology;    Serosurveillance;    Immunity;   

DOI  :  10.1186/s12916-021-01993-8

来源: Springer

【 摘 要 】

BackgroundIn 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.MethodsA 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.ResultsOver 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.ConclusionsWe 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.

【 授权许可】

CC BY