Evaluation of the direct agglutination test as an immunodiagnostic tool for kala-azar in India

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 87; no. 3; pp. 276 - 278
• Main Authors: Singla, Neena, Singh, G.S., Sundar, Shyam, Vinayak, V.K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.05.1993; Royal Society of Tropical Medicine and Hygiene; Elsevier
• Subjects: Agglutination Tests - methods; Agglutination Tests - standards; Animals; Antibodies, Helminth - analysis; Biological and medical sciences; Human protozoal diseases; Humans; Infectious diseases; Leishmania donovani; Leishmania donovani - immunology; Leishmania donovani - isolation & purification; Leishmaniasis, Visceral - diagnosis; Leshmaniasis; Medical sciences; Parasitic diseases; Protozoal diseases; Sensitivity and Specificity; Tropical medicine; Asia; India; Human; Infection; Evaluation; Protozoal disease; Immunological investigation; Antibody; Kala azar; Agglutination test; Serology; Leishmaniasis; Diagnosis
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/0035-9203(93)90125-A

The direct agglutination test (DAT) has been assessed as a diagnostic procedure for visceral leishmaniasis. Fifty-six of 58 sera (96·5%) from confirmed cases of visceral leishmaniasis, whose bone marrow aspirates contained Leishmania donovani amastigotes, had agglutinating antibodies above the cut-off titre of 1:800. None of the sera from healthy control subjects from non-endemic or endemic areas had anti-leishmanial antibodies. Similarly, none of the sera obtained from cases of malaria or tuberculosis had agglutinating antibodies above the cut-off titre. A significant decline in agglutinating antibody titre in 3 cases following anti-leishmanial chemotherapy appeared to correlate with regression of clinical symptoms and the absence of amastigotes from bone marrow aspirates. One of 3 cases developed post-kala-azar dermal lesions and sera from this subject had an elevated agglutinating antibody titre. It is concluded that the DAT is a sensitive and specific test to confirm visceral leishmaniasis. As the formalin-fixed promastigotes, stained with Coomassie blue, which are used as antigen could be stored at 4 °C for 6 months without any loss of ability to detect anti-leishmanial antibodies, the DAT is recommended for use under field conditions.