Abstract

Kala-azar is an infectious disease that mostly affects children under 5 years old, and, in untreated cases, is fatal. There are several routine serological tests employed to diagnose the disease, but these tests have disadvantages. Parasitological diagnosis tools are accurate but invasive, while molecular tools are expensive and not commonly used. We report that the newly developed kAtex test is a rapid, non invasive and simple tool for the detection of visceral leishmaniasis (VL), capable of detecting and distinguishing between recovered, subclinical and latent cases. The study was carried out in endemic areas of Kalibar and Ahar districts, East Azerbaijan province, Northwest Iran. Urine and Sera samples were collected from 313 children under age 5 years old from the endemic area. Additionally, sera and urine of 18 confirmed VL patients were studied. Urine samples were tested by kAtex kit to detect VL antigen. All sera samples were also tested by other serological tests such as DAT, IFA, and ELISA(IgG and IgM). kAtex tests were positive for 10 out of 313 examined urine samples of children and 2 positive samples for ELISA-IgM, but were negative all for other serological tests. During clinical follow up of the kAtex positive individuals, three of them developed VL disease, with DAT titers for these individuals reaching 1/3200. The results show that kAtex is an effective screening test for latent infection of VL. The test discriminates between active disease, sub clinical and latent infections. Its results can complement DAT for the diagnosis of unconfirmed visceral leishmaniasis cases.

Key words: KAtex, visceral leishmaniasis, diagnosis, Iran.