Evaluation of the Binax Now® Ict Test Versus Polymerase Chain Reaction and Microscopy for the Detection of Malaria in Returned Travelers

Abstract

Microscopic detection of Plasmodium species has been the reference standard for the diagnosis of malaria for more than a century. However, maintaining a sufficient level of expertise in microscopic diagnosis can be challenging, particularly in non-endemic countries. The objective of this study was to compare a new rapid malaria diagnostic device (NOW ICT Malaria Test; Binax, Inc., Portland, ME) to polymerase chain reaction (PCR) and expert microscopy for the diagnosis of malaria in 256 febrile returned travelers. Compared with PCR, the NOW ICT test showed a sensitivity of 94% for the detection of P. falciparum malaria (96% for pure P. falciparum infection) and 84% for non-P. falciparum infections (87% for pure P. vivax infections and 62% for pure P. ovale and P. malariae infections), with an overall specificity of 99%. The Binax NOW ICT may represent a useful adjunct for the diagnosis of P. falciparum and P. vivax malaria in febrile returned travelers.

Evaluation of a rapid diagnostic test (CareStart™ Malaria HRP-2/pLDH (Pf/pan) Combo Test) for the diagnosis of malaria in a reference setting

“…In line with studies on other RDTs [7,16,27,28], there was a correlation between line intensities and parasite densities, and there were, although to a lesser extent than observed for another RDT [7], diagnostic clues to parasite densities when scoring line intensities (such as a strong HRP-2 line intensity indicating a parasite density > 100/μl). The low intensities of the pan-pLDH lines, especially for the non- falciparum species, are of concern especially when extrapolating the present findings to field settings in both endemic and non-endemic settings, where disregarding faint test lines as negative results is a common mistake [29-33].…”

“…Reported sensitivities for the detection of P. vivax were significantly higher than those found in the present study in case of the CareStart™ Malaria pLDH (pan) (91.0%), but for the CareStart™ Malaria pLDH (pan/Pf) they were in line with the present findings (78.5%). Studies evaluating other RDTs in non-endemic countries report similar sensitivities as those found for the CareStart™ Malaria HRP-2/pLDH (Pf/pan) Combo Test in the present study: for P. falciparum they ranged from 87.5-99.0%, with one exception of 76.2% [7,10,16-21]. For P. vivax , RDTs detecting pan-pLDH showed sensitivities of 33.5% and 62.0%-95.0%,[7,10,13,18,20,22] compared to 46.0%-93.0% [13] for those RDTs targeting aldolase.…”

Evaluation of the Immunoquick+4 malaria rapid diagnostic test in a non-endemic setting

“…Reported sensitivities for P. falciparum range from 87.5 to 99.0%, with one exception of 76.2% [3,[10][11][12][13][14][15][16]. However, the Immunoquick+4 did not reach the 95% sensitivity for parasite densities >100/µl recommended by the WHO [17].…”

Is Serial Testing Required to Diagnose Imported Malaria in the Era of Rapid Diagnostic Tests?

“…[15][16][17] Because laboratories would usually not perform an RDT if a diagnosis of malaria had already been made by a blood film, RDTs were repeated in only a small number of cases. However, of those that did have a serial RDT, only two cases had positive subsequent test results for which the first RDT result and blood film had been negative, and only one case with a positive first blood film and a negative first RDT result had a subsequently positive RDT result on the third test.…”