Risk factors for high-risk human papillomavirus detection among HIV-negative and HIV-positive women from Tanzania

BACKGROUND: Human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. The prevalence is dependent on several known factors notably sexual behavior and age, and factors still under scrutiny.

OBJECTIVE: This study aimed to examine risk factors for high-risk (HR) HPV infection among HIV-positive and HIV-negative women from the general population of Tanzania and to assess whether specific risk factors could contribute to the high prevalence of HR HPV infection in older age found in some populations including Tanzanian women.

METHODS: A cross-sectional study of 3699 women from Tanzania was conducted. We obtained information on sociodemographic and lifestyle factors through personal interview. Cervical swabs were collected for detection of HR HPV (Hybrid Capture 2; Qiagen, Hildesheim, Germany) and genotyping (LiPaExtra; Innogenetics, Gent, Belgium). Finally, we obtained a blood sample for HIV testing.

RESULTS: HIV positivity was the strongest risk factor for HR HPV (odds ratio, 4.1; 95% confidence interval, 3.3-5.3). Young age, shorter duration of present relationship, and increasing number of sex partners were also associated with higher risk for HR HPV. Among women 20 to 29 years old, especially number of partners (P = 0.005) and HIV positivity (P < 0.0001) determined the risk. In underweight women 50 years or older (P = 0.004) and HIV positivity (P = 0.0009) increased the risk, whereas increasing number of partners was not related to the risk of HR HPV (P = 0.46).

CONCLUSIONS: Human papillomavirus risk factors among HIV-positive and HIV-negative women were similar, but the strength of association was greater among HIV-positive women, notably for lifetime number of sex partners, time in present relationship, genital warts, and body mass index. We were not able to identify a clear explanation for the high HPV prevalence among older women. However, in the age-stratified analysis, potential indicators of decreased immunity increased the risk for HPV infection among older women, whereas in younger women, risk was particularly associated with sexual activity.