Polymerase chain reaction. A sensitive indicator of the prevalence of human papillomavirus DNA in a population with sexually transmitted disease.

A total of 311 cervical samples from first attenders at a sexually transmitted disease clinic assayed for human papillomavirus (HPV) DNA with ViraType (VT) were analyzed with the polymerase chain reaction (PCR) for HPV using HPV L1 consensus primers and typed using L1 type-specific probes for 6/11, 16, 18 and 33. The prevalence of HPV by PCR was almost double that by VT (23.5% as compared to 12.6%, respectively). The increase was due largely to HPV types other than 6/11, 16, 18 and 33 (61.8%), while HPV types 6/11, 16 and 18 were responsible for 5.9%, 2.9% and 11.8%, respectively. Equal numbers of mixed infections of HPV 6/11/18 and HPV 16/18 each contributed to 8.8%. Mixed infection, as determined by VT, was 11% and increased to 40% with PCR. While the increase in the HPV detection rate by PCR was evident in all clinical categories examined (patients with no warts evident and no past history of warts, with no warts but a past history of warts and with clinical condylomata), a statistically significant increase occurred only in the first group, reflecting the increased sensitivity of PCR in detecting latent infection.