Abstract:
Visceral leishmaniasis (VL) or kala-azar is a chronic protozoan infection in humans
that is fatal unless treated and is associated with significant global morbidity and
mortality. Confirmation of visceral leishmaniasis (VL) diagnosis requires
microscopic examination to visualize the causative agent Leishmania Donovani in
spleen or bone marrow aspirate. Kala-azar latex agglutination based test (KATEX)
antigen test for VL in buccal swabs has not been evaluated locally and could offer a
significant advantage in screening patients suspected of VL. The study was
conducted after approval from KEMRI Scientific Ethical Review Unit (SERU).
Buccal swabs were obtained from VL cases and controls patients presenting at
Kimalel Health Centre, Baringo County, Kenya. Latex agglutination based test
(KATEX) was used to detect parasite antigen in buccal swabs. The study evaluated
the ability to use KATEX, a simple non-invasive diagnostic test to detect leishmania
antigens in buccal swabs, determine the ability of the kit to detect leishmania
antigens in buccal cells of kala-azar patients and compare the sensitivity and
specificity of KATEX - buccal assay using microscopy as the gold standard. Eighty
eight samples were analyzed using statistics and data (STATA) software version 13.2
standard edition, including 44 VL and 44 non-VL patients. KATEX kit was able to
detect visceral leishmaniasis antigens from buccal swabs giving a sensitivity of
(81.8%; 95%CI: 67.3% to 91.8% and specificity of (79.5%; 95%CI: 64.7 –90.2%).
Buccal swab test assay using KATEX is an easy test to perform and promising noninvasive based antigen detection test which may be useful for screening kala-azar
patients and could be applied in the diagnosis of VL. It is a functional assay that
warrants a larger study with a larger sample size for the purpose of evaluating the
utility of the test in diagnosing visceral leishmaniasis
