MALARIA: Comparative evaluation of two rapid field tests for malaria diagnosis: Partec Rapid Malaria Test(R) and Binax Now(R) Malaria Rapid Diagnostic Test.

Bernard Nkrumah et al. BMC Infectious Diseases 2011, 11:143 
Background

About 90% of all malaria deaths in sub-Saharan Africa occur in children under five years. Fast and reliable diagnosis of malaria requires confirmation of the presence of malaria parasites in the blood of patients with fever or history suggestive of malaria; hence a prompt and accurate diagnosis of malaria is the key to effective disease management. Confirmation of malaria infection requires the availability of a rapid, sensitive, and specific testing at an affordable cost. We compared two recent methods (the novel Partec Rapid Malaria Test(R) (PT) and the Binax Now(R) Malaria Rapid Diagnostic Test (BN RDT) with the conventional Giemsa stain microscopy (GM) for the diagnosis of malaria among children in a clinical laboratory of a hospital in a rural endemic area of Ghana.

Methods
Blood samples were collected from 263 children admitted with fever or a history of fever to the pediatric clinic of the Agogo Presbyterian Hospital. The three different test methods PT, BN RDT and GM were performed independently by well trained and competent laboratory staff to assess the presence of malaria parasites. Results were analyzed and compared using GM as the reference standard.

Results
In 107 (40.7%) of 263 study participants, Plasmodium sp. was detected by GM. PT and BN RDT showed positive results in 111 (42.2%) and 114 (43.4%), respectively. Compared to GM reference standard, the sensitivities of the PT and BN RDT were 100% (95% CI: 96.6-100) and 97.2% (95% CI: 92.0-99.4), respectively, specificities were 97.4% (95% CI: 93.6-99.3) and 93.6% (95% CI: 88.5-96.9), respectively. There was a strong agreement (kappa) between the applied test methods (GM vs PT: 0.97; p <0.001 and GM vs BN RDT: 0.90; p <0.001). The average turnaround time per tests was 17 minutes.

Conclusion
In this study two rapid malaria tests, PT and BN RDT, demonstrated a good quality of their performance compared to conventional GM. Both methods require little training, have short turnaround times, are applicable as well as affordable and can therefore be considered as alternative diagnostic tools in malaria endemic areas. The species of Plasmodium cannot be identified.

http://www.biomedcentral.com/1471-2334/11/143/abstract

MALARIA: Evaluation of Rapid Diagnostic Test for the Diagnosis of Severe Malaria in 2 Populations of African Children.

Clin Infect Dis. 2011 May;52(9):1100-7.

Evaluation of a PfHRP2 and a pLDH-based Rapid Diagnostic Test for the Diagnosis of Severe Malaria in 2 Populations of African Children.
Hendriksen IC, Mtove G, Pedro AJ, Gomes E, Silamut K, Lee SJ, Mwambuli A, Gesase S, Reyburn H, Day NP, White NJ, von Seidlein L, Dondorp AM.
Mahidol-Oxford Research Unit, Bangkok, Thailand.

Background. 
Rapid diagnostic tests (RDTs) now play an important role in the diagnosis of falciparum malaria in many countries where the disease is endemic. Although these tests have been extensively evaluated in uncomplicated falciparum malaria, reliable data on their performance for diagnosing potentially lethal severe malaria is lacking.

Methods. 
We compared a Plasmodium falciparum histidine-rich-protein2 (PfHRP(2))-based RDT and a Plasmodium lactate dehydrogenase (pLDH)-based RDT with routine microscopy of a peripheral blood slide and expert microscopy as a reference standard for the diagnosis of severe malaria in 1898 children who presented with severe febrile illness at 2 centers in Mozambique and Tanzania.

Results. 
The overall sensitivity, specificity, positive predictive value, and negative predictive values of the PfHRP(2)-based test were 94.0%, 70.9%, 85.4%, and 86.8%, respectively, and for the pLDH-based test, the values were 88.0%, 88.3%, 93.2%, and 80.3%, respectively. At parasite counts <1000 parasites/μL (n = 173), sensitivity of the pLDH-based test was low (45.7%), compared with that of the PfHRP(2)-based test (69.9%). Both RDTs performed better than did the routine slide reading in a clinical laboratory as assessed in 1 of the centers.

Conclusion. 
The evaluated PfHRP2-based RDT is an acceptable alternative to routine microscopy for diagnosing severe malaria in African children and performed better than did the evaluated pLDH-based RDT.

PMID: 21467015 [PubMed - in process] PMCID: PMC3070869Free PMC Article
http://www.ncbi.nlm.nih.gov/pubmed/21467015