Laboratory methods for detection of herpes simplex virus-1in herpetic keratitis patients

ABSTRACT

Herpetic ocular disease is a major cause of blindness. Rapid and accurate diagnosis is essential for prompt, proper treatment. The purpose of this study was to evaluate molecular methods as rapid diagnostic tools compared with cell culture of HSK. Corneal scrapings from [55] patients with clinically typical dendritic corneal ulcer suggestive of HSV keratitis, and [20] patients with clinically non-viral corneal ulcers as control, were tested by Giemsa stain for multinucleated giant cells, immunofluorescence assay [IFA] for HSV-1 antigen, and polymerase chain reaction [PCR] for HSV-1 DNA, and an attempt for viral isolation was performed on Vero cell line culture. Positive samples by cell culture were 27.3%, whereas PCR was positive in [34.6 %] and IFA was positive in [29%.] PCR had better sensitivity [100%] than IFA [70%]; however, IFA had better specificity [88%] and the difference was significant; P>.001. Their sensitivity were significantly higher than Giemsa stain. This indicates that a combination of IFA and PCR constitute the choice of tests in clinically suspected cases of HSV keratitis, multinucleated giant cells in Giemsa stain may give Presumptive diagnosis of viral infection