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.
Lifetime number of sex partners, time in present relationship, genital warts and body mass index had a stronger association with human papillomavirus infection among HIV-positive women than among HIV-negative women.
From the *Department of International Health, Public Health Institute, University of Copenhagen, Copenhagen, Denmark; †Department of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark; ‡Department of Obstetrics and Gynecology, Odense University Hospital, Odense, Denmark; §Division of Cancer Prevention, Ocean Road Cancer Institute, Dar es Salaam, United Republic of Tanzania; ¶Division of Experimental Virology, Universitaetsklinikum, Tuebingen, Germany; and ∥Gynaecological Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
Supported by Danida, the Department of Public Health, Faculty of Health and Medical Sciences (University of Copenhagen), and the Danish Cancer Society Research Center (Unit of Virus, Lifestyle and Genes).
Conflict of interest: S.K. Kjaer received lecture fees, advisory board fees, and research grants through her institution from Merck (manufacturer of an human papillomavirus vaccine) and Sanofi Pasteur MSD. C. Munk received lecture fees and travel granted from Merck and Sanofi Pasteur MSD. T. Iftner received speaker honoraria from Innogenetics, Inc; Hologic; Gen-probe; and Qiagen Corporation. M. Dartell, V. Rasch, J. Mwaiselage, and C. Kahesa have no conflict of interest.
Contributorship statement: M.D., V.R., and S.K.K. conceived, prepared, and/or adapted the research protocol. M.D., C.K., and J.M. supervised the field teams and data and specimen collection. T.I. was responsible for the DNA laboratory testing of the samples. M.D., C.M., and S.K.K. analyzed the data, prepared the first draft, and finalized the writing of the manuscript. All authors commented on and contributed to the manuscript and take responsibility for the integrity of the data and the accuracy of the data analysis.
Correspondence: Susanne Krüger Kjaer, MD, DMSc, Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Strandboulevarden 49, DK-2100 Copenhagen Ø, Denmark. E-mail: firstname.lastname@example.org.
Received for publication February 09, 2013, and accepted May 30, 2013.