Accuracy of a Plasmodium falciparum specific histidine-rich protein 2 rapid diagnostic test in the context of the presence of non-malaria fevers, prior anti-malarial use and seasonal malaria transmission

Malar J. 2017 Jul 20;16(1):294. doi: 10.1186/s12936-017-1941-6.

Abstract

Background: It remains challenging to distinguish malaria from other fever causing infections, as a positive rapid diagnostic test does not always signify a true active malaria infection. This study was designed to determine the influence of other causes of fever, prior anti-malarial treatment, and a possible seasonality of the performance of a PfHRP2 RDT for the diagnosis of malaria in children under-5 years of age living in a malaria endemic area.

Methods: A prospective etiology study was conducted in 2015 among febrile children under 5 years of age in Burkina Faso. In order to assess the influence of other febrile illnesses, prior treatment and seasonality on the performance of a PfHRP2 RDT in diagnosing malaria, the RDT results were compared with the gold standard (expert microscopic diagnosis of Plasmodium falciparum) and test results were analysed by assuming that prior anti-malarial use and bacterial/viral infection status would have been known prior to testing. To assess bacterial and viral infection status blood, urine and stool samples were analysed.

Results: In total 683 blood samples were analysed with microscopy and RDT-PfHRP2. Plasmodium falciparum malaria was diagnosed in 49.8% (340/683) by microscopy compared to 69.5% (475/683) by RDT-PfHRP2. The RDT-PfHRP2 reported 29.7% (141/475) false positive results and 1.8% (6/340) false negative cases. The RDT-PfHRP2 had a high sensitivity (98.2%) and negative predictive value (97.1%), but a low specificity (58.9%) and positive predictive value (70.3%). Almost 50% of the alternative cause of fever were diagnosed by laboratory testing in the RDT false positive malaria group.

Conclusions: The use of a malaria RDT-PfHRP2 in a malaria endemic area may cause misdiagnosis of the actual cause of fever due to false positive test results. The development of a practical diagnostic tool to screen for other causes of fever in malaria endemic areas is required to save lives.

Keywords: Accuracy; Diagnosis; Fever; Malaria; RDT-PfHRP2; Sensitivity; Specificity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Protozoan*
  • Antimalarials / therapeutic use
  • Burkina Faso
  • Child, Preschool
  • Diagnostic Tests, Routine / standards*
  • Female
  • Fever / etiology
  • Humans
  • Infant
  • Infant, Newborn
  • Malaria, Falciparum / diagnosis*
  • Malaria, Falciparum / drug therapy
  • Malaria, Falciparum / transmission
  • Male
  • Plasmodium falciparum / isolation & purification*
  • Plasmodium falciparum / physiology
  • Protozoan Proteins*
  • Seasons
  • Sensitivity and Specificity

Substances

  • Antigens, Protozoan
  • Antimalarials
  • HRP-2 antigen, Plasmodium falciparum
  • Protozoan Proteins