Thesis (doctoral)--Ludwig-Maxilimilians-Universität zu München, 1993. / Includes bibliographical references.

No description available.

Thesis (Ph. D.)--Lund University, 1997. / Added t.p. with thesis statement inserted.

Thesis (Ph. D.)--Lund University, 1997. / Added t.p. with thesis statement inserted.

Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States, but few studies have examined the progression from HPV infection to disease in men. Genital condyloma are the most common clinical manifestation of HPV infection. Though not associated with mortality, condyloma are a source of emotional distress, and treatment is often painful with a high recurrence rate. The aims of this study were to examine the distribution of HPV types present on the surface of condyloma, estimate the incidence of condyloma overall and after type-specific HPV infections, assess the sociodemographic and sexual behavior factors independently associated with incident condyloma, and examine the concordance between HPV types detected on the surface and in the tissue of condyloma. Participants included 2,487 men from the United States, Brazil, and Mexico who were enrolled in the prospective HPV in Men (HIM) Study and followed every six months for up to four years. At each study visit men completed a computer-assisted-self-administered risk factor questionnaire and samples of healthy penile skin were obtained to test for HPV DNA. A trained clinician examined men for the presence of condyloma and swabbed the surface of lesions to test for HPV DNA. Men were followed for a median of 17.9 months and 112 incident condyloma were identified. Thirty-four external genital lesions were also biopsied to test for HPV within the lesion tissue. PCR was used to test for HPV DNA and Linear Array was used to genotype 13 oncogenic and 24 non-oncogenic HPV types in samples obtained from swabbing the lesion surface. The LiPa assay was used to genotype 20 HPV types in biopsy samples. The Kaplan-Meier method was used to estimate incidence and Cox proportional hazards models were used to examine factors independently associated with incident condyloma. Using biopsy samples as the gold standard, sensitivity and specificity were calculated to examine concordance between HPV types detected on the surface and within the tissue of condyloma. Condyloma incidence was 2.35 per 1,000 person-years. HPV 6 (43.8%), 11 (10.7%), and 16 (9.8%) were the most common types detected on condyloma. The probability of developing condyloma within 24-months of an incident HPV 6/11 infection was 14.6% (95% confidence interval (CI): 7.5-21.1). The median time to condyloma development was 17.1 months (95% CI: 12.4-19.3), with the shortest time to detection observed among men with incident HPV infections with types 6/11 only (6.2 months; 95% CI: 5.6-24.2). Factors associated with condyloma were incident HPV 6/11 infection (hazard ratio (HR) = 12.42; 95% CI: 3.78-40.77), younger age (HR = 0.43; 95% CI: 0.26-0.77; 45-70 vs. 18-30 years), high lifetime number of female partners (HR = 5.69; 95% CI: 1.80-17.97); 21 or greater vs. 0), and sexual behaviors in the previous three months including infrequent condom use (HR = 2.44; 95% CI: 1.16-5.14;

Background: Persistent infection with high risk HPV is a necessary but insufficient cause of cervical cancer. Behavioural, viral and host factors modulate the risk of HPV persistence. In this thesis, I explore the role of the vaginal microbiota, a host factor and the presence of multiple HPV infections, a viral factor in HPV persistence. Considering the limited data on the epidemiology of HPV related diseases in low and middle-countries (LMIC), and the limited success of cervical cancer screening strategies in many LMIC, I provide data on the distribution of HPV related diseases in Nigeria and evaluate the acceptability of innovative strategies to increase cervical cancer screening uptake. Methods/Results: To achieve my aims, I implemented a longitudinal cohort study of 1,020 women in Nigeria. I begin my results chapters with two methodological papers. Attrition is an important consideration for every longitudinal cohort, particularly in LMIC, therefore, I present my findings on attrition, determinants of attrition and practical strategies to ensure low attrition in studies conducted in LMIC. Considering that sexual behaviour is an important potential confounder in all HPV studies, and the reliability of self-reported history is often questioned, I present findings on the test-retest reliability of self-reported sexual behaviour history collected in my study. Having found that attrition levels were low and that self-reported sexual behaviour history was generally reliable within my cohort, I present my findings on the association between the vaginal microbiota and persistent hrHPV; and the role of multiple HPV infections in viral persistence. I found that the vaginal microbiota was associated with persistent hrHPV in HIV negative women, but not in HIV positive women; and that multiple HPV infections did not increase the risk of viral persistence when compared to single HPV infections. Next, I present my findings on the prevalence and incidence of anogenital warts in Nigeria, with additional reports on the prevalence of cervical cancer and other HPV associated cancers using data from two population based cancer registries. Finally, I present my findings on the acceptability of innovative strategies to improve cervical cancer screening uptake in Nigeria. I found that Nigerian women had a favorable attitude to the use of HPV DNA based screening as part of routine antenatal care, however attitudes towards the use of self-sampling techniques for HPV based cervical cancer screening varied by religious affiliations. Conclusion: In my thesis, I was able to systematically investigate the epidemiology of HPV infections in a LMIC. I considered the distribution of HPV related diseases, host and viral determinants of HPV persistence and investigated control strategies to reduce the burden of cervical cancer in a LMIC. My results provide useful data for surveillance, monitoring and evaluation of control programs on HPV and cervical cancer in Nigeria and may be useful to cervical cancer control programs in other LMIC.

Introduction. Sexually transmitted infections (STIs) continue to be highly prevalent among young women, and STIs continue to be a challenging health issue on college campuses. Studies have shown that the highest prevalence of human papillomavirus (HPV) is among young adult women, ages 20 to 24, including female college students. While the HPV vaccine has proven to be highly effective in preventing certain high-risk types of HPV, it is not effective in preventing all types of HPV or other STIs. Practicing other safer sex behaviors, in addition to condom use, also can help individuals protect themselves and their partners from acquiring HPV and other STIs. Purpose. Relationships between knowledge about HPV and the HPV vaccine, beliefs about HPV, acceptance of the HPV vaccine, and intentions to practice safer sex behaviors were assessed to determine if female college students who had a high acceptance of the HPV vaccine were also more likely to practice safer sex behaviors. Methods. A convenience sample of 2,706 undergraduate female college students, ages 18 to 24, from three U.S. public universities, completed an online survey that measured the following study variables: knowledge about HPV; knowledge about the HPV vaccine; acceptance of the HPV vaccine, specifically influential factors and barriers to vaccination; as well as attitudes, normative beliefs, control beliefs and intentions for practicing safer sex behaviors. Results. The majority of participants had a high level of knowledge of HPV (70.4%) and the HPV vaccine (73.7%). Over one-third of the participants (37.3%) received at least one dose of the HPV vaccine. Most participants thought they had a low susceptibility to HPV, as 54% thought they were unlikely to contract HPV; however, most (53.6%) thought that HPV would be a serious problem for them. The safer sex behavior that participants thought was the easiest was refusing to have sex with a partner that would not use a condom (51.8% “Strongly agree”) and the safer sex behavior that participants thought to be the most difficult was asking a partner to get tested for STIs (54.5% “Disagree”). Attitudes, normative beliefs, and control beliefs combined to strongly predict intentions (R = .730, p < .001), and attitudes was the strongest predictor for intentions to practice safer sex behaviors (β = .666), 95% CI [.649, .711]. There was a significant positive correlation between vaccine acceptance and intentions to practice safer sex behaviors (r = .087, p < .001), including likelihood of getting vaccinated against HPV (r = .098, p < .001). Conclusions. Findings from this study demonstrate the need for university student health centers to provide information about the HPV vaccine as part of broader STI prevention and social marketing campaigns, targeting female college students who are single, as well as those in monogamous relationships. Furthermore, because young men can be carriers of HPV and the HPV vaccine is now available to them, follow-up studies are needed to determine acceptance of the HPV vaccine among male college students as it relates to HPV knowledge, knowledge of the vaccine, and intentions to practice safer sex behaviors.