False-negative malaria rapid diagnostic tests in Rwanda: impact of Plasmodium falciparum isolates lacking hrp2 and declining malaria transmission

Malaria Journal

Research

Jean Pierre Habimana¹  Noella Umulisa²  Corine Karema³  Jean Pierre Musabyimana⁴  Emil I. Mwikarago⁴  Stephen Rulisa⁵  Donald J. Krogstad⁶  Christina T. Kozycki⁶ 

[1] Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda;Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda;Maternal and Child Survival Programme, Jhpiego, Kigali, Rwanda;Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda;Swiss Tropical and Public Health Institute, Basel, Switzerland;University of Basel, Basel, Switzerland;Quality and Equity Healthcare, Kigali, Rwanda;National Reference Laboratory, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda;School of Medicine and Pharmacy, University of Rwanda, Kigali, Rwanda;Tulane University Health Science Center, New Orleans, LA, USA;

关键词: Malaria;    Plasmodium falciparum;    Rapid diagnostic test (RDT);    Histidine rich protein 2 (HRP2);    Plasmodium;    Sensitivity;    Polymerase chain reaction (PCR);    Rwanda;   

DOI  :  10.1186/s12936-017-1768-1

 received in 2016-11-22, accepted in 2017-03-08,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundRapid diagnostic tests (RDTs) for histidine rich protein 2 (HRP2) are often used to determine whether persons with fever should be treated with anti-malarials. However, Plasmodium falciparum parasites with a deletion of the hrp2 gene yield false-negative RDTs and there are concerns the sensitivity of HRP2-based RDTs may fall when the intensity of transmission decreases.MethodsThis observational study enrolled 9226 patients at three health centres in Rwanda from April 2014 to April 2015. It then compared the sensitivity of RDTs based on HRP2 and the Plasmodium lactate dehydrogenase (pLDH) to microscopy (thick smears) for the diagnosis of malaria. PCR was used to determine whether deletions of the histidine-rich central repeat region of the hrp2 gene (exon 2) were associated with false-negative HRP2-based RDTs.ResultsIn comparison to microscopy, the sensitivity and specificity of HRP2- and pLDH-based RDTs were 89.5 and 86.2% and 80.2 and 94.3%, respectively. When the results for both RDTs were combined, sensitivity rose to 91.8% and specificity was 85.7%. Additionally, when smear positivity fell from 46 to 3%, the sensitivity of the HRP2-based RDT fell from 88 to 67%. Of 370 samples with false-negative HRP2 RDT results for which PCR was performed, 140 (38%) were identified as P. falciparum by PCR. Of the isolates identified as P. falciparum by PCR, 32 (23%) were negative for the hrp2 gene based on PCR. Of the 32 P. falciparum isolates negative for hrp2 by PCR, 17 (53%) were positive based on the pLDH RDT.ConclusionThis prospective study of RDT performance coincided with a decline in the intensity of malaria transmission in Kibirizi (fall in slide positivity from 46 to 3%). This decline was associated with a decrease in HRP2 RDT sensitivity (from 88 to 67%). While P. falciparum isolates without the hrp2 gene were an important cause of false-negative HRP2-based RDTs, most were identified by the pLDH-based RDT. Although WHO does not recommend the use of combined HRP2/pLDH testing in sub-Saharan Africa, these results suggest that combination HRP2/pLDH-based RDTs could reduce the impact of false-negative HRP2-based RDTs for detection of symptomatic P. falciparum malaria.

【 授权许可】

CC BY   
© The Author(s) 2017