Imported visceral leishmaniasis: diagnostic dilemmas and comparative analysis of three assays

The present study evaluates the performances of three noninvasive serological assays for the detection of immunoglobulin G antibodies to leishmania antigen for the diagnosis of imported cases of kala azar (visceral leishmaniasis [VL]) in a country, Kuwait, where the disease is not endemic. A total of 323 individuals including 21 patients with documented cases of VL, 72 individuals with suspected cases of VL, 155 patients with other parasitic infections, and 75 healthy control individuals were tested by indirect hemagglutination assay (IHA; Behring Diagnostics GmbH, Marburg, Germany), indirect fluorescent-antibody assay (IFA; bioMerieux sa, Marcy l'Etoile, France), and a qualitative membrane-based immunoassay with recombinant leishmania antigen K39 (strip-test; Intersep Ltd, Berkshire, United Kingdom). Our data show that IHA is the most sensitive test (100%), followed by IFA (86.6%) and the strip-test (80.0%). The strip-test was the most specific (100%) of the three assays, followed by IFA (93.0%) and IHA (86.0%). However, the strip-test failed to detect at least three confirmed cases of VL. We conclude that IHA is preferred over IFA and the strip-test for the screening of individuals with suspected cases of VL, especially in a country where VL is not endemic and where the number of cases is regular but limited. The details about some of the patients with VL are presented to highlight the diversity of clinical presentations and problems encountered in the diagnosis of VL in a country where VL is not endemic.