Acta Tropica 78 (2001) 11–16 Latex agglutination test for the detection of urinary antigens in visceral leishmaniasis Zamil J. Attar a , Michael L. Chance a , Sayda el-Safi b , James Carney c , Ahmed Azazy d , Maha El-Hadi b , Cibele Dourado a , Marcel Hommel a, * a Molecular Biology and Immunology Diision, Lierpool School ofTropical Medicine, Lierpool, L35QA, UK b Department of Microbiology and Parasitology, Uniersity of Khartoum, Khartoum, Sudan c Kalon Biological Ltd, Ash Vale, GU12 5QJ, UK d Faculty of Medicine & Health Sciences, Sana’a Uniersity, Sana’a, Republic of Yemen Received 4 April 2000; received in revised form 21 August 2000; accepted 25 August 2000 Abstract This paper describes a new latex agglutination test (‘KATEX’) for the detection of leishmanial antigen in the urine of patients with visceral leishmaniasis. In preliminary laboratory trials, using urine collected from well-defined cases and controls from Brazil, Yemen and Nepal, the test had 100% specificity and a sensitivity between 68 and 100%. When used in a time-course experiment in cotton rats infected with Leishmania donoani, the test became positive 1 week after inoculation and antigen levels in urine declined rapidly after chemotherapy (the test was negative before the end of the course of treatment). Finally, in an integrated study performed in Sudan, KATEX was compared to microscopy and four different serological tests in a group of 73 patients having presented with clinical manifestations suggestive of visceral leishmaniasis. Compared to microscopy, KATEX performed better than any single serological test in predicting positivity and a particularly good result was obtained by combining KATEX and the direct agglutination test (DAT). © 2001 Published by Elsevier Science B.V. Keywords: Kala azar; Visceral leishmaniasis; Diagnostic; KATEX; Latex; Urine antigen www.parasitology-online.com 1. Introduction Visceral leishmaniasis (VL), is a disease with an annual incidence of 500 000 cases worldwide and an estimated 200 million individuals at risk of contracting the infection (Ashford et al., 1992); the fact that 90% of clinical cases occur in the poorest communities in developing countries is an important consideration with regard to diagnosis and treatment. Clinical diagnosis relies on non- characteristic symptoms (cachexia, anaemia, chronic fever with hepato-splenomegaly) and is only reliable in advanced cases and in epidemic situations. Mortality of VL is high in the absence of treatment (using mostly injectable pentavalent antimony) which is lengthy (20–28 days in most regimes), very expensive and rather toxic. The * Corresponding author. Tel.: +44-151-708-9393. E-mail address: mhommel@liv.ac.uk (M. Hommel). 0001-706X/01/$ - see front matter © 2001 Published by Elsevier Science B.V. PII:S0001-706X(00)00155-8