Sensitivity and specificity of a rapid immunochromatographic test for diagnosis of visceral leishmaniasis

A rapid immunochromatographic dipstick test has become available for the qualitative detection of total anti-Leishmania immunoglobulins using the recombinant K39 antigen. To evaluate the test, 96 serum specimens from patients with a variety of tropical infections were tested. Fourteen of the specimens derived from patients with parasitologically confirmed kala-azar, and all were strongly positive for antibodies to Leishmania donovani complex using the immunofluorescence test. Although all 82 samples negative by the immunofluorescence test were confirmed as negative by the dipstick assay, only 10 (71.4%) of the 14 positive samples were reactive. These results indicate that the test in its current form lacks sufficient sensitivity to be recommended as a screening tool, but it might be useful for indicating further diagnostic procedures in a clinical setting.