DETECTION OF CYTOMEGALOVIRUS USING BOOSTED NESTED PCR

As a part of a study of an outbreak of CMV infections in a neonatal ca re intensive care unit, a modified nested PCR was developed for detect ion of CMV DNA in clinical specimens. Standard nested PCR involves a c ritical step; passage of PCR products from the first reaction round to the second round. We have adapted a 'boosted' nested PCR which implie s amplification in one single step, thus reducing the contamination pr oblems. Nasopharyngeal aspirates and urine samples from patients with perinatal CMV infections, breast milk from some of their mothers, amni otic fluids, urine samples and lymphocytes from seropositive healthy a dults were examined by PCR and culture. in the total of 614 of clinica l specimens, the PCR test yielded positive results in 51 samples from 14 patients, whereas CMV was isolated in 25 samples from 11 cases only . All samples from healthy individuals were negative. CMV DNA was dete cted in all culture-positive samples, but all samples from healthy adu lts were negative. 29/68 culture negative specimens were positive by P CR. No cross-reactivity to other herpes viruses or to human DNA was ob served. Our findings show a high sensitivity and a high specificity of the 'boosted' nested PCR. We conclude that the described PCR method c an be used for the rapid detection of CMV in clinical specimens with a greatly reduced risk of contamination, and it has proved to be a very useful tool in diagnostic work. (C) 1995 Academic Press Limited