A direct comparison of real time PCR on plasma and blood to detect Plasmodium falciparum infection in children

Malaria Journal

Methodology

Llorenç Quinto¹  Alfons Jiménez¹  Pau Cisteró¹  Pedro L Alonso²  Alfredo Mayor²  Caterina Guinovart²  Carlota Dobaño²  Ruth Aguilar²  Augusto Nhabomba³  Maria N Manaca³  Abigail A Lamikanra⁴  David J Roberts⁴  Hoi P Tsang⁴ 

[1] Barcelona Center for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló, 132, 4th floor, 08036, Barcelona, Spain;Barcelona Center for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló, 132, 4th floor, 08036, Barcelona, Spain;Centro de Investigação em Saúde da Manhiça (CISM), Vila de Manhiça, CP 1929, Maputo, Mozambique;Centro de Investigação em Saúde da Manhiça (CISM), Vila de Manhiça, CP 1929, Maputo, Mozambique;Nuffield Department of Clinical Laboratory Sciences, University of Oxford, OX3 9DU, Headington, Oxford, UK;National Health Service Blood and Transplant, John Radcliffe Hospital, OX3 9BQ, Headington, Oxford, UK;

关键词: Malaria;    qPCR;    Plasma;    Anaemia;   

DOI  :  10.1186/1475-2875-11-201

 received in 2012-03-26, accepted in 2012-06-15,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundEstimation of Plasmodium falciparum parasitaemia can vary with the method used and time of sampling. Quantitative real time PCR (qPCR) on whole blood or plasma samples has previously been shown to be more sensitive than thick film microscopy. However the efficiencies of each method have not been compared using samples obtained from infants less than one year old.MethodsA multiple of statistical approaches were used to compare the performance of qPCR on whole blood or plasma to detect the 18 S ribosomal gene of P. falciparum in 548 samples from children aged 2.5 or 24 months. Parasite prevalence in matched samples was compared using Mcnemar’s test and agreement of positive results quantified as Kappa scores. Parasite prevalences between different age groups were compared by Fisher’s test. Results from analyses by thick film microscopy were also available from children at 24 months and their correlation to each qPCR method examined by the Spearman’s test. Finally the association of P. falciparum infection with the incidence of multiple malaria episodes from contact to 24 months of age was evaluated using negative binomial regression.ResultsThese analyses showed that qPCR from whole blood detected approximately 3-fold more cases of infection than plasma qPCR. Both qPCR methods agreed well with each other although qPCR from plasma had a greater agreement with microscopy (96.85%) than did qPCR from blood (69.7%). At 24 months the prevalence of infection detected by all methods was associated with anaemia (p < 0.05).ConclusionsThe data presented here demonstrates that low levels of parasitaemia are better detected by qPCR using parasite DNA from whole blood than from plasma. However plasma samples provide a viable substitute when parasite smears are unavailable.

【 授权许可】

CC BY   
© Lamikanra et al.; licensee BioMed Central Ltd. 2012