David J Roberts and Alfredo Mayor contributed equally to this work.
The authors declare that they have no competing interests.
AAL contributed to acquisition, interpretation of data, drafting and revision of the manuscript, CD, AJ, AN, CG, MM, LQ and RA contributed to acquisition of the data, HPT and PC contributed to acquisition and analysis of data, PA critically revised and gave approval of the version to be published DJR Contributed to the conception, interpretation and design of the study, has critically revised and given approval of the version to be published, AM Contributed to the conception, interpretation and design of the study, drafting and revision of the manuscript, and given approval of the version to be published. All authors have read and approved the final manuscript.
Estimation 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.
A 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.
These 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).
The 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.
WHO: World Malaria Report 2011. 2011, Geneva: World Health Organization, http://www.who.int/malaria/world_malaria_report_2011/9789241564403_eng.pdf,
malERA Consultative Group on Diagnoses and Diagnostics: A research agenda for malaria eradication: diagnoses and diagnostics. PLoS Med. 2011, 8: e1000396- CrossRef
Rougemont M, Van Saanen M, Sahli R, Hinrikson HP, Bille J, Jaton K: Detection of four Plasmodium species in blood from humans by 18 S rRNA gene subunit-based and species-specific real-time PCR assays. J Clin Microbiol. 2004, 42: 5636-5643. 10.1128/JCM.42.12.5636-5643.2004. PubMedCentralCrossRefPubMed
Andrews L, Andersen RF, Webster D, Dunachie S, Walther RM, Bejon P, Hunt-Cooke A, Bergson G, Sanderson F, Hill AV, Gilbert SC: Quantitative real-time polymerase chain reaction for malaria diagnosis and its use in malaria vaccine clinical trials. Am J Trop Med Hyg. 2005, 73: 191-198. PubMed
Alonso PL, Sacarlal J, Aponte JJ, Leach A, Macete E, Milman J, Mandomando I, Spiessens B, Guinovart C, Espasa M, Bassat Q, Aide P, Ofori-Anyinam O, Navia MM, Corachan S, Ceuppens M, Dubois MC, Demoité MA, Dubovsky F, Menéndez C, Tornirporth N, Ballou WR, Thompson R, Cohen J: Efficacy of the RTS, S/AS02A vaccine against Plasmodium falciparum infection and disease in young African children: randomised controlled trial. Lancet. 2004, 364: 1411-1420. 10.1016/S0140-6736(04)17223-1. CrossRefPubMed
Guinovart C, Dobaño C, Bassat Q, Nhabomba A, Quintõ L, Nélia Manaca M, Aguilar R, Rodríguez M, Barbosa A, Aponte J, Mayor A, Renom M, Moraleda C, Roberts DJ, Schwarzer E, Le Souëf PN, Schofield L, Chitnis CE, Doolan DL, Alonso PL: The role of age and exposure to Plasmodium falciparum in the rate of acquisition of naturally acquired immunity: a randomized controlled trial. PloS ONE. 2012, 7: e32362-10.1371/journal.pone.0032362. PubMedCentralCrossRefPubMed
Mayor A, Serra-Casas E, Bardaji A, Sanz S, Puyol L, Cistero P, Sigauque B, Mandomando I, Aponte JJ, Alonso PL, Menéndez C: Sub-microscopic infections and long-term recrudescence of Plasmodium falciparum in Mozambican pregnant women. Malar J. 2009, 8: 9-10.1186/1475-2875-8-9. PubMedCentralCrossRefPubMed
Schachterle S, Mtove G, Levens J, Clemens EG, Shi L, Raj A, Munoz B, Reller ME, West S, Dumler JS, Sullivan D, PRET Project Team: Prevalence and density related concordance of three diagnostic tests for malaria in hypoendemic Tanzania. J Clin Microbiol. 2011, 49: 3885-3891. 10.1128/JCM.01157-11. PubMedCentralCrossRefPubMed
Waitumbi JN, Gerlach J, Afonina I, Anyona SB, Koros JN, Siangla J, Ankoudinova I, Singhal M, Watts K, Polhemus ME, Vermeulen NM, Mahoney W, Steele M, Domingo GJ: Malaria prevalence defined by microscopy, antigen detection, DNA amplification and total nucleic acid amplification in a malaria-endemic region during the peak malaria transmission season. Trop Med Int Health. 2011, 16: 786-793. 10.1111/j.1365-3156.2011.02773.x. CrossRefPubMed
Bull PC, Lowe BS, Kaleli N, Njuga M, Kortok M, Ross A, Ndungu F, Snow RW, Marsh K: Plasmodium falciparum infections are associated with agglutinating antibodies to parasite-infected erythrocyte surface antigens among healthy Kenyan children. J Infect Dis. 2002, 185: 1688-1691. 10.1086/340420. CrossRefPubMed
Han ET, Watanabe R, Sattabongkot J, Khuntirat B, Sirichaisinthop J, Iriko H, Jin L, Takeo S, Tsuboi T: Detection of four Plasmodium species by genus- and species-specific loop-mediated isothermal amplification for clinical diagnosis. J Clin Microbiol. 2007, 45: 2521-2528. 10.1128/JCM.02117-06. PubMedCentralCrossRefPubMed
- A direct comparison of real time PCR on plasma and blood to detect Plasmodium falciparum infection in children
Abigail A Lamikanra
Hoi P Tsang
Maria N Manaca
Pedro L Alonso
David J Roberts
- BioMed Central
Neu im Fachgebiet Innere Medizin
Meistgelesene Bücher aus der Inneren Medizin
Mail Icon II