Use of nested polymerase chain reaction for the detection of cytomegalovirus in clinical specimens.

BACKGROUND & OBJECTIVES: Since fluorescent antibody test (FAT) has low sensitivity in the rapid detection of cytomegalovirus (CMV) in clinical specimens, a nested polymerase chain reaction (nPCR) to detect the CMV-DNA was evaluated.

METHODS

nPCR and FAT were carried out to detect CMV in single specimens from 104 patients and dual specimens from 32 patients with suspected active CMV infection. Of the 136 patients, 3 were HIV positive.

RESULTS

CMV was detected by FAT alone in 3 (1.8%) and FAT and nPCR in 16 (9.5%) specimens and by nPCR alone in 84 (50.0%) specimens from 74 (54.4%) patients. nPCR increased the clinical sensitivity by 50.0 per cent in the specimens and 54.4 per cent in the patients (McNemar test, P < 0.001). Urine was found to be the ideal specimen for the detection of CMV as the detection rate in the urine was statistically higher (McNemar test, P < 0.05) than in the blood. Buffy coat and plasma samples from 35 normal blood donors were subjected to nPCR and ELISA respectively. CMV-DNA was not detected in any of the samples while anti-CMV antibodies were detected in all of them.

INTERPRETATION & CONCLUSION: The results showed that presence of CMV-DNA in the specimen indicates active infection and nPCR is a rapid, sensitive, specific and a more reliable diagnostic tool than FAT.