Improvement of direct agglutination test (DAT) for laboratory diagnosis of visceral leishmaniasis in Brazil

Oliveira, Edward; Pedras, Mariana Junqueira; Assis, Isabella Elias Morais de; Rabello, Ana

doi:10.1016/j.trstmh.2009.04.007

« Previous Next »Transactions of the Royal Society of Tropical Medicine and Hygiene
Volume 103, Issue 12 , Pages 1279-1281, December 2009

Improvement of direct agglutination test (DAT) for laboratory diagnosis of visceral leishmaniasis in Brazil

Clinical Research Laboratory, Centro de Pesquisa René Rachou, Fundação Oswaldo Cruz, Av. Augusto de Lima, 1715, Belo Horizonte, MG, 30190-002, Brazil

Received 6 November 2008; received in revised form 9 April 2009; accepted 9 April 2009.

Summary

We previously standardized the direct agglutination test (DAT) to detect anti-Leishmania chagasi promastigote antibodies (DAT-LPC) with good sensitivity and specificity for diagnosing visceral leishmaniasis (VL). In this paper, we present a technical upgrade by introducing some modifications into the antigen preparation. This antigen was evaluated in DAT (DAT-Mod) using 61 sera samples from VL patients and 96 samples from patients with other diseases. The DAT-Mod presented a cut-off of 1:100, satisfactory reproducibility (VC <5.8), sensitivity of 93.4%, specificity of 96.9%, and diagnostic efficiency of 95.5%. The improvement in antigen preparation reduced inter-batch variations and resulted in a high test performance.

Keywords: Visceral leishmaniasis, Serologic test, Diagnosis, DAT, Sensitivity and specificity, Brazil