Performance evaluation of Active Melioidosis Detect-Lateral Flow Assay (AMD-LFA) for diagnosis of melioidosis in endemic settings with limited resources.

Abstract

Melioidosis is a fatal infection caused by the soil saprophyte Burkholderia pseudomallei. Early diagnosis and befitting medical management can significantly influence the clinical outcomes among patients with melioidosis. Witnessing an annual increment in the number of melioidosis cases, over the past few years, mainly from the developing tropical nations, the present study was undertaken to evaluate the diagnostic utility of Active Melioidosis DetectTMLateralFlow Assay (AMD-LFA), in comparison with enrichment culture and PCR. A total of 206clinical specimens obtained from 175 patients with clinical suspicion of melioidosis were considered for the evaluation. Positivity for B.pseudomallei using enrichment culture, PCR and AMD-LFA were observed among 63 (30.5%), 55 (26.6%) and 63 (30.5%) specimens respectively. The AMD-LFA failed to detect melioidosis from 9 culture-confirmed cases (6 whole blood specimens, 2 pus samples, and one synovial fluid). Further the test gave faint bands from 9 urine samples which were negative by culture and PCR. AMD-LFA demonstrated a sensitivity, specificity, of 85.71%(CI:74.61% to 93.25%) and 93.62% (CI:88.23% to 97.04%), with positive predictive value of 85.71% (CI: 75.98% to 91.92%) and negative predictive value of 93.62% (CI:88.89% to 96.42%). The test needs further evaluation in view of the faint bands from negative urine samples, for incorporating the test as a point of care assay.In view of its rapidity and ease of testing AMD-LFA might be useful in early diagnosis of melioidosis at resource constraint settings.