Human papillomavirus infection in Danish female sex workers - Decreasing prevalence with age despite continuously high sexual activity

Background: The prevalence of the human papillomavirus (HPV) has been found to decrease with age, but whether this applies to all populations is not c lear. Knowledge about the generalizability of this age dependency is import ant to understand the natural history of the infection, but may also have i mplications in relation to the use of HPV testing in cervical cancer screen ing. Goal: To study the prevalence and risk factors for HPV infection in a selec ted population of female sex workers and to compare the results with person s with different sexual habits from two other populations in the same geogr aphic area, Study Design: A case-control study among 188 female sex workers from Copenh agen. Data were obtained by personal interviews. Cervical material was coll ected by a self-administered lavage kit, and HPV testing was done by means of GP5+/6+ primers based on HPV, polymerase chain reaction, enzyme immunoas say. Results: Among sex workers, age was the most important risk factor for HPV infection. Number of private sex partners in the last 4 months was also a s ignificant risk factor, and a protective effect of condom use was indicated . Conclusion: The HPV prevalence is declining in sex workers with age despite continuously high sexual activity, most likely indicating that an immune r esponse is acquired over time.