Chlamydia trachomatis prevalence and chlamydial/HPV co-infection among HPV-unvaccinated young Italian females with normal cytology

Abstract

Infections caused by Chlamydia trachomatis (Ct) and human papillomavirus (HPV) are the two main sexually transmitted infections; however, epidemiological data on Ct prevalence and Ct/HPV co-infection in Italy are scant. This study aimed at estimating the prevalence of Ct infection and Ct/HPV co-infection in young HPV-unvaccinated females with normal cytology, and placed particular attention on the possible association between Ct-DNA positivity and different HPV infecting genotypes. Five hundred 66 healthy females aged 16–26 years without cervical lesions, previously assessed for HPV infection (HPV-DNA prevalence: 18.2%), were tested for Ct-DNA. The overall prevalence of Ct was 5.8% (95% CI: 4.2–8.1), while Ct/HPV co-infection was recorded in 2.7% (95% CI: 1.6–4.3) of subjects. Compared with HPV-DNA-negative females, HPV-DNA positive subjects had significantly (P < 0.001) higher odds of being infected with Ct (odds ratio of 4.20, 95% CI: 2.01–8.71). Both Ct and Ct/HPV infections were much more prevalent in under 18-year-olds than in older women. Subjects positive for single high-risk HPV genotypes and various multiple HPV infections had higher odds of being Ct-DNA positive. Our findings confirm that HPV and Ct infections are very common among asymptomatic young Italian females. This underlines the urgent need for nationwide Ct screening programs and reinforcement of sexual health education, which would be the most important public health strategies, since no Ct vaccines are currently available.

Keywords: :

• Chlamydia trachomatis
• Human papillomavirus
• HPV
• HPV/Chlamydia trachomatis co-infection
• sexually transmitted infections
• young women

Disclosure of Potential Conflicts of Interest

No potential conflicts of interest were disclosed.

Acknowledgements

The study was financed by the Italian Ministry of University and Research (MIUR, project PRIN 2009; Grant number: 2009ZPM4X4). The authors thank: Dr Angela Lidia Grondona, Dr Elisa Di Capua, Dr Paolo Cristoforoni, Dr Roberto Ferraro, Dr Massimo Benzi, Dr Paola Voltolina, and Dr Albina Godani for their support in sample collection. They also thank Dr Klodiana Sulaj, Dr Morena Martinese, Dr Miriam Divita, and Dr Graziella Romani for their support in data collection and quality control.

The authors thank Dr Bernard Patrick for revising the manuscript.