Comparison between virus isolation method, Papanicolaou stain, immunoperoxidase stain and polymerase chain reaction in the diagnosis of genital herpes.

Papanicolaou (Pap) stain, immunoperoxidase (IP) stain and polymerase chain reaction (PCR) were evaluated against the virus isolation method for their sensitivity and specificity in the diagnosis of herpes simplex virus (HSV) infection in 96 women who were suspected of genital herpes. The result showed that the sensitivity of PCR, IP and Pap stain was 100, 92.0 and 62.7%, respectively, while the specificity was 76.2, 66.7 and 81.0%, respectively. PCR was even more sensitive than the virus isolation technique. As Pap stain is the technique routinely performed for diagnosing genital herpes in most of the hospitals in Thailand, its low sensitivity should be taken into consideration. Based on the investigation by all four techniques together, HSV infection was diagnosed in 91.6% of the cases suspected of genital herpes which reflected higher precision of the clinical diagnosis over Pap stain.