Estimating the prevalence of Trichomonas vaginalis, Chlamydia trachomatis,Neisseria gonorrhoeae, and human papillomavirus infection in indigenous women in northern Australia

Objective: To estimate more accurately the age specific prevalence of Trich omonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, and human p apillomavirus infection (HPV) in indigenous women living in urban, rural, a nd remote areas of the "Top End" of the Northern Territory (NT). Design: Analysis of data obtained from two community based studies using se lf administered tampon specimens tested by polymerase chain reaction for se xually transmitted disease (STD). Data pertaining to the notifiable STDs (N gonorrhoeae and C trachomatis) were obtained from the NT health department . Patients: 1090 indigenous women (age range 12-73 years) were enrolled when they attended local community health centres, family planning clinics, and STD clinics. The majority attended clinics in their home community in the c ourse of "well women's checks" which encourage women to undergo screening f or a variety of general medical conditions. Results: The overall prevalence of T vaginalis, C trachomatis, N gonorrhoea e, and HPV was 0.25 (95% CI: 0.22-0.28), 0.11 (0.09-0.13), 0.17 (0.15-0.19) , and 0.42 (0.37-0.48) respectively. Of the women found to be infected (exc luding HPV), 25.5% had two or more of the above organisms detected. There w as a statistically significant increase in the age specific prevalence of T vaginalis but a significant decrease with age for C trachomatis and HPV in fection. There was no statistically significant change for N gonorrhoeae wi th age. Conclusions: STDs are hyperendemic in this population of indigenous women a nd the notification data significantly underestimate their prevalence. Dist inct patterns of age specific prevalence were demonstrated, highlighting th e need to tailor control strategies to specific epidemiological features.