Field deployment of loop-mediated isothermal amplification for centralized mass-screening of asymptomatic malaria in Zanzibar: a pre-elimination setting

Malaria Journal

Research

Iveth J González¹  Ulrika Morris²  Berit Aydin-Schmidt²  Anders Björkman²  Andreas Mårtensson³  Jackie Cook⁴  Abdullah S Ali⁵  Mwinyi Khamis⁵  Ali K Abass⁵  Mwinyi I Msellem⁵  Majda H Nassor⁵ 

[1] Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland;Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden;Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden;Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden;Centre for Clinical Research Sörmland, Uppsala University, Uppsala, Sweden;Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden;London School of Hygiene and Tropical Medicine, London, UK;Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania;

关键词: Plasmodium;    Malaria;    Low-density;    Asymptomatic;    Loop-mediated isothermal amplification;    Mass screening;    DNA contamination;   

DOI  :  10.1186/s12936-015-0731-2

 received in 2015-03-23, accepted in 2015-05-08,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundMolecular tools for detection of low-density asymptomatic Plasmodium infections are needed in malaria elimination efforts. This study reports results from the hitherto largest implementation of loop-mediated isothermal amplification (LAMP) for centralized mass screening of asymptomatic malaria in Zanzibar.MethodsHealthy individuals present and willing to participate in randomly selected households in 60 villages throughout Zanzibar were screened for malaria by rapid diagnostic tests (RDT). In 50 % of the study households, participants were asked to provide 60 μL of finger-prick blood for additional LAMP screening. LAMP was conducted in two centralized laboratories in Zanzibar, by trained technicians with limited or no previous experience of molecular methods. The LAMP assay was performed with LoopampTM MALARIA Pan/Pf Detection Kit (Eiken Chemical Company, Japan). Samples positive for Plasmodium genus (Pan)-LAMP were re-tested using Plasmodium falciparum-specific LAMP kits.ResultsPaired RDT and LAMP samples were available from 3983 individuals. The prevalence of asymptomatic malaria was 0.5 % (CI 95 % 0.1-0.8) and 1.6 % (CI 95 % 1.1-2.2) by RDT and Pan-LAMP, respectively. LAMP detected 3.4 (CI 95 % 2.2-5.2) times more Plasmodium positive samples than RDT. DNA contamination was experienced, but solved by repetitive decontamination of all equipment and reagents.ConclusionsLAMP is a simple and sensitive molecular tool, and has potential in active surveillance and mass-screening programmes for detection of low-density asymptomatic malaria in pre-elimination settings. However, in order to deploy LAMP more effectively in field settings, protocols may need to be adapted for processing larger numbers of samples. A higher throughput, affordable closed system would be ideal to avoid contamination.

【 授权许可】

CC BY   
© Morriset al.; licensee BioMed Central. 2015