Detection of Leishmania in the blood of early kala-azar patients with the aid of the polymerase chain reaction

Abstract

Samples from 39 patients with symptoms suggestive of early visceral leishmaniasis were independently assayed by microscopy of tissue smears, enzyme-linked immunosorbent assay (elisa) and polymerase chain reaction (PCR) of blood deoxyribonucleic acid. Of these patients, 19 were confirmed as positive or negative by all 3 tests; 11 patients (28%) negative by smear were positive by elisa and PCR; and 7 (18%) were positive by PCR alone. These results demonstrate the high sensitivity of the non-invasive PCR and, to a smaller extent, elisa, in the early diagnosis of visceral leishmaniasis.