Placental Plasmodium falciparum malaria infection: Operational accuracy of HRP2 rapid diagnostic tests in a malaria endemic setting

Malaria Journal

Research

Lynette K Tumwine¹  Prudence Hamade²  Sylvia Meek²  Mark Montague²  Helen Counihan²  Clare Riches³  James K Tibenderana⁴  Daniel J Kyabayinze⁵  Mercy Nassali⁶  Jean-Pierre Van Geertruyden⁷ 

[1] College of Health Sciences, Makerere University, PO Box 7072, Kampala, Uganda;Malaria Consortium, Development House, 56-64 Leonard Street, EC2A 4LT, London, UK;Malaria Consortium, P.O. Box 8045, Upper Naguru East Road, Kampala, Uganda;Malaria Consortium, P.O. Box 8045, Upper Naguru East Road, Kampala, Uganda;London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK;Malaria Consortium, P.O. Box 8045, Upper Naguru East Road, Kampala, Uganda;Unit International Health, ESOC Department, Faculty of Medicine, Antwerp University, Universiteiplein 1, BE-2610, Antwerpen, Belgium;Mbale Regional Referral Hospital, Ministry of Health, PO Box 192, Mbale, Uganda;Unit International Health, ESOC Department, Faculty of Medicine, Antwerp University, Universiteiplein 1, BE-2610, Antwerpen, Belgium;

关键词: Malaria;    Positive Predictive Value;    Negative Predictive Value;    Malaria Infection;    Placental Malaria;   

DOI  :  10.1186/1475-2875-10-306

 received in 2011-08-01, accepted in 2011-10-18,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundMalaria has a negative effect on the outcome of pregnancy. Pregnant women are at high risk of severe malaria and severe haemolytic anaemia, which contribute 60-70% of foetal and perinatal losses. Peripheral blood smear microscopy under-estimates sequestered placental infections, therefore malaria rapid diagnostic tests (RDTs) detecting histidine rich protein-2 antigen (HRP-2) in peripheral blood are a potential alternative.MethodsHRP-2 RDTs accuracy in detecting malaria in pregnancy (MIP >28 weeks gestation) and placental Plasmodium falciparum malaria (after childbirth) were conducted using Giemsa microscopy and placental histopathology respectively as the reference standard. The study was conducted in Mbale Hospital, using the midwives to perform and interpret the RDT results. Discordant results samples were spot checked using PCR techniques.ResultsAmong 433 febrile women tested, RDTs had a sensitivity of 96.8% (95% CI 92-98.8), specificity of 73.5% (95% CI 67.8-78.6), a positive predictive value (PPV) of 68.0% (95% CI 61.4-73.9), and negative predictive value (NPV) of 97.5% (95% CI 94.0-99.0) in detecting peripheral P. falciparum malaria during pregnancy. At delivery, in non-symptomatic women, RDTs had a 80.9% sensitivity (95% CI 57.4-93.7) and a 87.5% specificity (95%CI 80.9-92.1), PPV of 47.2% (95% CI 30.7-64.2) and NPV of 97.1% (95% CI 92.2-99.1) in detecting placental P. falciparum infections among 173 samples. At delivery, 41% of peripheral infections were detected by microscopy without concurrent placental infection. The combination of RDTs and microscopy improved the sensitivity to 90.5% and the specificity to 98.4% for detecting placental malaria infection (McNemar's X2> 3.84). RDTs were not superior to microscopy in detecting placental infection (McNemar's X2< 3.84). Presence of malaria in pregnancy and active placental malaria infection were 38% and 12% respectively. Placental infections were associated with poor pregnancy outcome [pre-term, still birth and low birth weight] (aOR = 37.9) and late pregnancy malaria infection (aOR = 20.9). Mosquito net use (aOR 2.1) and increasing parity (aOR 2.7) were associated with lower risk for malaria in pregnancy.ConclusionUse of HRP-2 RDTs to detect malaria in pregnancy in symptomatic women was accurate when performed by midwives. A combination of RDTs and microscopy provided the best means of detecting placental malaria. RDTs were not superior to microscopy in detecting placental infection. With a high sensitivity and specificity, RDTs could be a useful tool for assessing malaria in pregnancy, with further (cost-) effectiveness studies.

【 授权许可】

CC BY   
© Kyabayinze et al; licensee BioMed Central Ltd. 2011