Comparative performance of direct agglutination test, indirect immunofluorescent antibody test, polymerase chain reaction and bone marrow aspiration method for diagnosis of Mediterranean visceral leishmaniasis

Abstract

The objectives of this study were to compare the sensitivities and reliabilities of direct agglutination test (DAT), indirect immunofluorescent antibody test (IFAT), polymerase chain reaction (PCR) and bone marrow aspiration for the diagnosis of Mediterranean visceral leishmaniasis (MVL) using blood samples. Blood samples were collected from 67 confirmed MVL patients and 47 patients with other diseases such as malaria, tuberculosis, echinococcosis, toxoplasmosis and leukemia and; 10 healthy individuals as control group. MVL was more frequently diagnosed in children less than 2 years-old (44.8%). The highest sensitive diagnostic method was IFAT (85.1 %) while the least one was bone marrow aspiration (42.8%). The specificity of DAT (100%) was higher than IFAT (80.8%, CI = 66.3 to 90.4%). Comparison of the two serological methods revealed that DAT had a higher positive predictive value (100%) whereas IFAT had a higher negative predictive value (86.4%). The highest degree of agreement (agreement = 71.6%, Kappa = 0.13) was found between IFAT and DAT. Moreover, the minimum number of false negative results (1 out of 55 patients) was found when IFAT and PCR were applied simultaneously(agreement = 69.1%, Kappa = - 0.09). Therefore, we suggest the application of IFAT and PCR methods in endemic areas of visceral leishmaniasis for early and accurate diagnosis and to avoid misdiagnosis of MVL. Key words: Mediterranean visceral leishmaniasis, indirect immunofluorescent antibody test, direct agglutination test, polymerase chain reaction, bone marrow aspiration.