A team of researchers recently discovered that using the polymerase chain reaction (PCR) assay is more efficient and accurate than using the immunofluorescence assay to detect herpes virus in corneal scrapings and grafts of suspected herpetic keratitis patients.

The study evaluated the corneal scrapings and grafts of 1,926 suspected herpetic keratitis patients; 1,863 were processed with immunofluorescence assay and 302 with PCR assay to detect herpes virus. Of the 302 patients that underwent PCR, clinical specimens from 239 were analyzed by both that test and immunofluorescence.

Of the 1,863 suspected herpetic keratitis patients diagnosed by immunofluorescence, the researchers found 277 (14.9%) were positive for herpes simplex virus 1 antigen. Of the 302 suspected herpetic keratitis patients diagnosed by PCR, they note 70 (23.2%) were positive for herpes simplex virus DNA. In their report, the team added that of the 239 patients diagnosed by both PCR and immunofluorescence, 35 (14.6%) were positive with immunofluorescence assay, 59 (24.7%) with PCR assay and 30 (12.5%) with both.

The study concludes, “although the immunofluorescence assay is a rapid test for the detection of herpes virus in suspected herpetic keratitis patients, a combination of polymerase chain reaction with immunofluorescence assay will provide (more) reliable and accurate results.”