REACTIVITY OF VARIOUS LEISHMANIAL ANTIGENS IN A DIRECT AGGLUTINATION-TEST AND THEIR VALUE IN DIFFERENTIATING POST-KALA AZAR DERMAL LEISHMANIASIS FROM LEPROSY AND OTHER SKIN CONDITIONS

A direct agglutination test (DAT) for the detection of post-kala azar dermal leishmaniasis (PKDL) was evaluated in conditions that simulate the disease clinically or immunologically. A reference strain of Leish mania donovani (LEM 1399), and antigen preparations from two Leishmani a isolates from Bangladeshi patients with post-kala azar dermal leishm aniasis or visceral leismaniasis were used. A titre of at least 51 200 was obtained in tests of patients with PKDL with all three antigens, whereas a maximum titre of 1600 was recorded in patients with cutaneou s leishmaniasis, mucocutaneous leishmaniasis or leprosy, Antigens from dermal isolates of L. tropica (LV 140) and L. braziliensis (LV 65) yi elded titres of 1600-6400 in patients with PKDL. The lowest titre reco rded in 70 patients tested with the homologous PKDL antigen was 409 60 0. In patients with leprosy, cutaneous leishmaniasis, syphilis, onchoc erciasis, tuberculosis, blastomycosis or vitiligo, titres ranged from 100 to 1600. The DAT is better than current parasitological and histop athological methods for the diagnosis of PKDL in areas in which lepros y is co-endemic.