Comparative studies on IFAT, ELISA & DAT for serodiagnosis of visceral leishmaniasis in Bangladesh.

The purpose of the study was to estimate the specificity and sensitivity of different serological methods for the diagnosis of visceral leishmaniasis in Bangladesh. Blood samples from 155 suspected kala-azar patients together with 80 sick subjects and 50 healthy subjects from the endemic areas were collected. Out of the 155 suspected kala-azar patients, bone marrow were collected from 126 patients. All bone marrow samples were examined by direct microscopy. 92 bone marrow samples were also examined by culture method. Blood samples were examined by various serological tests. Out of 126 marrow samples, LD bodies were present by microscopy in 77 (61.1%) cases and out of 92 marrow samples, cultures for LD bodies were positive in 33 (35.9%) cases. All the three serological tests (IFAT, ELISA & DAT) were positive in all parasitologically positive kala-azar patients. They were also positive in seven (15.5%) out of 45 parasitologically negative cases and 10 (34.4%) out of remaining 29 cases in whom bone marrow samples were not available. Thus the serological tests proved to be simple, non-invasive, highly sensitive and specific methods for the diagnosis of visceral leishmaniasis. DAT is the simplest of these serological tests, although these tests did not differ in sensitivity and specificity.