A simple and sensitive test for field diagnosis of post kala-azar dermal leishmaniasis

Abstract

Background Current methods for diagnosis of post kala-azar dermal leishmaniasis (PKDL) do not offer adequate sensitivity and specificity. Objectives To develop a simple and sensitive test for field diagnosis of PKDL. Methods Immunochromatographic nitrocellulose strips precoated with recombinant k39 antigen were evaluated for the detection of circulating antibodies to leishmanial k39 in PKDL sera. A drop of serum applied to the strip followed by buffer led to the development of two visible bands indicating the presence of anti-k39 IgG. Results The strip test was able to detect cases of PKDL with 91% sensitivity. The specificity of the test was evaluated using controls with other skin diseases, other common infections and healthy persons from endemic and non-endemic regions. Of 125 controls examined, all were negative on the strip test, indicating 100% specificity of the test. Conclusions The immunochromatographic nitrocellulose strips provide a non-invasive, rapid and accurate method for diagnosing PKDL.