Rapid Diagnosis of Vivax Malaria by the SD Bioline Malaria Antigen Test When Thrombocytopenia Is Present

Abstract

An easy and reliable diagnostic method for malaria is highly desirable. We examined the recently introduced SD Bioline Malaria Antigen test, which detects Plasmodium lactate dehydrogenase, with the additional aid of the presence or absence of thrombocytopenia to diagnose vivax malaria. We enrolled 732 patients with clinically suspected malaria in an area where vivax malaria is endemic. We performed microscopic examination of thin film, applied the SD Bioline Malaria Antigen test, and checked platelet counts. One hundred ninety-five patients were smear positive for vivax malaria. The sensitivity of the SD Bioline Malaria Antigen test was 96.4%, and its specificity was 98.9%. We found that 95.4% of malaria patients had thrombocytopenia, and the proportion with malaria increased as platelet counts decreased. A positive SD Bioline Malaria Antigen test when thrombocytopenia was present showed a 100% positive predictive value for vivax malaria. In conclusion, the SD Bioline Malaria Antigen test is a rapid and accurate diagnostic method for vivax malaria, and a platelet count can facilitate a rapid diagnosis of malaria.

Evaluation of the SD FK70 Malaria Ag Plasmodium vivax rapid diagnostic test in a non-endemic setting

“…Two previous studies assessed the performance of the FK70 in a P. vivax -endemic setting. In a prospective clinical study, Lee and co-workers demonstrated sensitivity and specificity of 96.4% and 98.9% respectively [ 15 ]. However, they did not include data on parasite densities and the control group only consisted of malaria-negative samples.…”

Malaria Diagnosis: A Brief Review

“…conventional microscopic diagnosis by staining thin and thick peripheral blood smears [16], other concentration techniques, e.g. quantitative buffy coat (QBC) method [15], rapid diagnostic tests e.g., OptiMAL [17,18], ICT [19], Para-HIT-f [10], ParaScreen [20], SD Bioline [21], Paracheck [22], and molecular diagnostic methods, such as polymerase chain reaction (PCR) [23,24]. Some advantages and shortcomings of these methods have also been described, related to sensitivity, specificity, accuracy, precision, time consumed, cost-effectiveness, labor intensiveness, the need for skilled microscopists, and the problem of inexperienced technicians.…”

“…Some tests detect P. falciparum specific and pan-specific antigens (aldolase or panmalaria pLDH), and distinguish non-P. falciparum infections from mixed malaria infections. Although most RDT products are suitable for P. falciparum malaria diagnosis, some also claim that they can effectively and rapidly diagnose P. vivax malaria [21,42,43]. Recently, a new RDT method has been developed for detecting P. knowlesi [44].…”

Malaria rapid diagnostic tests in endemic settings

“…The lower specificity of PfHRP2‐detecting RDTs can partly be explained by the slow clearance of PfHRP2: in patients with recently treated or self‐cleared infections PfHRP2 may persist in the blood for several weeks and still be present during a new episode of fever. For P. vivax diagnosis, reported sensitivities for pan‐pLDH, Pv‐pLDH and aldolase‐detecting RDTs are, respectively, 76.1–100.0% , 76.9–100.0% and 80.0–81.4% . A prospective field study in Peru, comparing side‐to‐side 11 RDT products, revealed high sensitivity (>99.0%) for 9/11 products with no difference between pan‐pLDH vs. Pv‐pLDH detection .…”