Use of the recombinant K39 dipstick test and the direct agglutination test in a setting endemic for visceral leishmaniasis in Nepal.

We evaluated the field use of two serologic tests for visceral leishmaniasis (VL), the direct agglutination test (DAT) and rK39 dipstick test, in the context of a case-control study. Most VL cases in Nepal are currently diagnosed on clinical grounds and with relatively non-specific tests such as the formol-gel test. Among 14 newly diagnosed VL patients with bone-marrow slides confirmed positive in two independent laboratories, the sensitivity of both tests was 100%. Among 113 controls with no personal or household history of VL, the specificity of the rK39 was 100% while that of the DAT was 93%. The rK39 was less expensive than DAT, and has the advantages of ease of use and obtaining results within minutes. The wider use of the rK39 dipstick test could improve the specificity of VL diagnosis in Nepal.