RESUMO
Visceral Leishmaniasis [kala-azar] is the most important endemic disease in Northwestern Iran, particularly in Ardabil province. This study aimed to review the Seroepidemiological studies which have been performed in Ardabil province during 1986-2009. In this descriptive analytical study, studies which have been carried out from 1986 through 2009 in Northwestern Iran about clinical, diagnostic and epidemiological features of Kala azar, using DAT, were reviewed. Collected data were analyzed using the SPSS software. in total, 2703 of human visceral leishmaniasis were detected by direct agglutination test [DAT] in Ardabil province, 1787 [66.1%] of them were from Meshkin-shahr district, 837 [31%] cases were from Moghan district, and 79 [2.9%] cases were from Ardabil district. Ninety eight percent of the cases were under 10 years old while only 0.5% of the VL cases were >/= 20 years old and 17% of them were under 1 year of age. Currently Kala-Azar is the most important endemic disease in Northwestern Iran, particularly in Ardabil province. Anti-Leishmania antibodies at the titers of >/= 1:3200 using DAT along with clinical signs including fever, anemia and hepatosplenomegaly are considered as active visceral leishmaniasis. DAT antibody titer of 1/800 and lower and absent of clinical signs is considered as negative VL.