Short Communication: Evaluation of a New Rapid Diagnostic Test for Quality Assurance by Kala Azar Elimination Programme in Bangladesh

In Bangladesh, serological tests have been widely used for the primary screening of visceral leishmaniasis (VL). Several serologic tests are available for the diagnosis of VL. Selection of the best test is important to permit diagnostic differentiation between symptomatic and asymptomatic patients and to reduce cross-reactivity. We evaluated the effectiveness of a new serological test “Onsite Leishmania Ab Rapid Test” as a part of “quality assurance” activities for the kala azar elimination programme of the Government of Bangladesh. Plasma samples of 100 parasitologically confirmed cases of VL along with 101 healthy controls were tested, and “Onsite Leishmania Ab Rapid Test” strip tests were positive in 94 out of 100 confirmed VL cases, whereas four out of 51 healthy subjects from the VL endemic areas also tested positive. All the 50 healthy volunteers tested negative. Thus, the sensitivity and specificity of “Onsite Leishmania Ab Rapid Test” strip test were found to be 94% (95% CI: 87–98) and 96% (95% CI: 90–99), respectively. This study showed that the performance of the “Onsite Leishmania Ab Rapid Test” strip tests was up to the recommended level. 1. Introduction Kala azar or visceral leishmaniasis (VL) is a vector-borne parasitic disease endemic in 45 of 64 districts of Bangladesh where 65 million people have been estimated to be at risk of contracting the disease [1]. The disease presents with prolonged fever, anemia, splenomegaly, anorexia, and wasting and is typically found among the rural poor of the endemic countries. India, Bangladesh, and Nepal together account for about 60% of all the new cases of kala azar which is an estimated 500,000 every year [2]. The governments of India, Bangladesh, and Nepal signed an agreement in 2005 to make joint efforts to eliminate kala azar from this region. The strategy for the elimination programme relies on three main components: rapid diagnosis, effective treatment, and integrated vector control. An immunochromatographic test based on a recombinant 39-amino acid repeat antigen, conserved in the kinesin region of Leishmania chagasi, known as rK-39 strip test has been the most widely accepted rapid diagnostic test for VL in South Asia [3, 4]. The WHO has recommended rK39 test as rapid diagnostic test (RDT) for VL in South Asia. The Government of Bangladesh (GoB) procured a new RDT kit with the brand name of “Onsite Leishmania Ab Combo” (CTK Biotech Inc., San Diego, Calif, USA) for the kala azar elimination programme through open bidding as per existing policy. The aim of the study was to evaluate the