Marcia L. Shew

The effects of race/ethnicity, income, and family structure on adolescent risk behaviors.

OBJECTIVES The study examined the unique and combined contributions of race/ethnicity, income, and family structure to adolescent cigarette smoking, alcohol use, involvement with violence, suicidal thoughts or attempts, and sexual intercourse. METHODS Analyses were based on the National Longitudinal Study of Adolescent Health. A nationally representative sample of 7th to 12th graders participated in in-home interviews, as did a resident parent for 85.6% of the adolescent subjects. The final sample included 10,803 White, Black, and Hispanic 7th to 12th graders. RESULTS White adolescents were more likely to smoke cigarettes, drink alcohol, and attempt suicide in the younger years than were Black and Hispanic youths. Black youths were more likely to have had sexual intercourse; both Black and Hispanic youths were more likely than White teens to engage in violence. Controlling for gender, race/ethnicity, income, and family structure together explained no more than 10% of the variance in each of the 5 risk behaviors among younger adolescents and no more than 7% among older youths. CONCLUSIONS Findings suggest that when taken together, race/ethnicity, income, and family structure provide only limited understanding of adolescent risk behaviors.

A Longitudinal Study of Genital Human Papillomavirus Infection in a Cohort of Closely Followed Adolescent Women

BACKGROUND We performed a study to better characterize the natural history of genital human papillomavirus (HPV) infection in a cohort of closely followed adolescent women. METHODS A cohort of 60 adolescent women was followed over a 2.2-year period, on average. A median of 41.5 self-collected vaginal and clinician-obtained cervical swabs were obtained from each subject. RESULTS HPV was detected in 45.3% of all adequate specimens, by use of a polymerase chain reaction/reverse blot strip assay. Oncogenic--or high-risk (HR)--HPV types were detected in 38.6% of specimens, and nononcogenic--or low-risk (LR)--types were detected in 19.6% of specimens. During the entire study period, 49 of 60 subjects tested positive for HPV (cumulative prevalence, 81.7%). The most frequently detected HR types were HPV types 52, 16, and 59. Infections with multiple HPV types were common. The median duration of persistence of a specific HPV type was 168 days, and HR types were more persistent than LR types. Abnormal cervical cytological results occurred in 37% of the adolescent women and were significantly associated with HR HPV infection. CONCLUSIONS The cumulative prevalence of HPV infection in sexually active adolescent women is extremely high, involves numerous HPV types, and frequently results in cervical dysplasia.

Vaccine-Type Human Papillomavirus and Evidence of Herd Protection After Vaccine Introduction

OBJECTIVES: The aims of this study were to compare prevalence rates of human papillomavirus (HPV) in young women before and after HPV vaccine introduction to determine the following: (1) whether vaccine-type HPV infection decreased, (2) whether there was evidence of herd protection, and (3) whether there was evidence for type-replacement (increased prevalence of nonvaccine-type HPV). METHODS: Young women 13 to 26 years of age who had had sexual contact were recruited from 2 primary care clinics in 2006–2007 for a prevaccination surveillance study (N = 368, none were vaccinated) and 2009–2010 for a postvaccination surveillance study (N = 409, 59% were vaccinated). Participants completed a questionnaire and were tested for cervicovaginal HPV DNA. HPV prevalence rates were compared in the pre- versus postsurveillance studies by using χ2 tests. Propensity score weighting was used to balance differences in covariates between the 2 surveillance studies. RESULTS: The mean age was ∼19 years for both groups of participants and most were African American and non-Hispanic. After propensity score weighting, the prevalence rate for vaccine-type HPV decreased substantially (31.7%–13.4%, P < .0001). The decrease in vaccine-type HPV not only occurred among vaccinated (31.8%–9.9%, P < .0001) but also among unvaccinated (30.2%–15.4%, P < .0001) postsurveillance study participants. Nonvaccine-type HPV increased (60.7%–75.9%, P < .0001) for vaccinated postsurveillance study participants. CONCLUSIONS: Four years after licensing of the quadrivalent HPV vaccine, there was a substantial decrease in vaccine-type HPV prevalence and evidence of herd protection in this community. The increase in nonvaccine-type HPV in vaccinated participants should be interpreted with caution but warrants further study.

Appropriate Use of Cervical Cancer Vaccine

Human papillomavirus (HPV) is a necessary, though not sufficient, cause of cervical cancer. Two vaccines have been developed that prevent two HPV types associated with 70% of cervical cancers. One of the vaccines (a quadrivalent vaccine) also prevents two HPV types associated with 90% of genital warts. Both HPV vaccines have shown very good efficacy and safety. This review summarizes the guidelines for use of the quadrivalent vaccine published by the Advisory Committee on Immunization Practices, presents data on vaccine efficacy and safety, and gives an overview of the findings of cost-effectiveness studies. In addition, we summarize the research on the attitudes of parents and health care providers toward HPV vaccine and critically evaluate controversial and challenging issues surrounding HPV vaccination, including concerns about sexual disinhibition and potential obstacles to vaccine distribution and uptake.

Interval between menarche and first sexual intercourse, related to risk of human papillomavirus infection

The purpose of this investigation was to study the occurrence of human papillomavirus (HPV) infection in relation to the interval between menarche and first intercourse. Two hundred eight subjects, aged 13 to 21 years, were recruited from an ambulatory adolescent clinic. Patients were excluded if they had a history of genital warts or an abnormal Papanicolaou smear. All subjects completed a self-administered questionnaire regarding demographics and their menstrual, sexual, and contraceptive histories. HPV infection was determined by in situ hybridization or changes consistent with HPV on a Papanicolaou smear, or both. The prevalence of HPV infection was 19.2%. The average interval between menarche and onset of sexual activity was 26.6 months for those who were found to have HPV infection compared with 35.7 months for those whose test results were negative (p = 0.02). First sexual intercourse within 18 months of menarche was associated with a significant elevation of risk of HPV infection, in comparison with that in adolescents who postpone first intercourse 3 to 4 years after menarche. These data suggest that factors such as increased biologic vulnerability may play a role in HPV infections among adolescent women.

REDUCTION OF HPV INFECTIONS THROUGH VACCINATION AMONG AT-RISK URBAN ADOLESCENTS

INTRODUCTION Human papillomavirus (HPV) vaccine trials have demonstrated high efficacy in preventing HPV infections and HPV related disease in females ages 16-26. However, there is no source data to demonstrate the impact of the vaccine in other populations who may be at higher risk for HPV related disease. This study examines the impact of HPV vaccination on subsequent HPV detection and sexual behaviors among urban adolescents in a clinical setting. METHODS A cohort of adolescent women, ages 14-17, were recruited prospectively and matched to historical controls to assess the impact of HPV vaccination. All women completed the same questionnaire and face-to-face interview that assessed sexual behaviors; all provided a clinician or self-collected vaginal swab that was used to test for sexually transmitted infections, including HPV. Logistic regression models, incorporating random pair effects, were used to assess the impact of the HPV vaccine on HPV detection and sexual behaviors between the two groups. RESULTS Each woman recruited (N=75) was matched to 2 historical controls (HC); most of the recruited women (89.3%) had received one or more doses of the HPV vaccine. At enrollment, detection of quadrivalent vaccine types (HPV 6, 11, 16 and 18) was significantly less in the recruited group (5.3%) as compared to the HC (24%): OR=5.6 (CI=1.9, 16.5), p=0.002. Adolescent women in the HC had a 9.5 times greater odds of HPV infection when the analysis was adjusted to compare those who had 2 or more vaccine doses to their matched controls. The only behavioral difference found was that the recruited women used condoms more frequently. CONCLUSION This study demonstrates that HPV vaccination was associated with fewer vaccine-type HPV infections despite incomplete vaccination and high risk sexual behaviors. These data also suggest that sexual behaviors were not altered because of the vaccine.

Accuracy of Self-Reported Human Papillomavirus Vaccine Receipt Among Adolescent Girls and Their Mothers

PURPOSE The use of self-report of human papillomavirus (HPV) vaccination status has several implications for clinical care and research. Reports of HPV vaccination history of adolescent girls (ages: 14-17 years) and their mothers were compared with medical chart data to assess the accuracy of HPV vaccine recall. METHODS Adolescent girls (N = 74) and their mothers independently completed questionnaires regarding HPV vaccination history, which were compared with medical chart data to assess the accuracy of HPV vaccine recall. RESULTS There were high levels of inaccuracy between actual HPV vaccination and self-report of vaccine receipt. Both mothers and daughters had poor recall of HPV vaccination, and were more likely to underestimate than overestimate the coverage. Girls who accurately reported their vaccination status were not more likely to have been sexually active in the past 2 months (p = .75). CONCLUSIONS These findings have clinical and research implications, as self-report is relied on to assess young womens vaccination status in research settings or in the absence of medical records. These data address the still prevalent concern that HPV vaccination encourages adolescent sexual behavior. It is unlikely that sexual behaviors will change as a result of vaccination in the large percentage of girls who cannot recall being vaccinated.

Association of Chlamydia trachomatis Infection With Redetection of Human Papillomavirus After Apparent Clearance

BACKGROUND Persistent infection with oncogenic human papillomavirus (HPV) is associated with an increased risk of cervical malignancy. Redetection of type-specific HPV after a period of nondetection may be caused by reactivation of a low-level persistent infection. Little is known about factors associated with type-specific HPV redetection. METHODS For a longitudinal cohort of adolescent women with frequent behavioral and sexually transmitted infection (STI) information (every 3 months), Cox proportional hazard models were used to assess the influence of sexual behaviors and STIs on the redetection of oncogenic or high-risk HPV infections. RESULTS A total of 210 type-specific high-risk HPV detection episode periods were identified in this longitudinal cohort; 71 (33.8%) were characterized by a period of nondetection followed by redetection. Chlamydia trachomatis (hazard ratio [HR], 3.14; 95% confidence interval [CI], 1.44-6.86) was associated with redetection; redetection was >2 times more likely with each additional self-reported sex partner in the past 3 months (HR, 2.26; 95% CI, 1.35-3.78). CONCLUSIONS This study demonstrates the role of C. trachomatis and number of recent sexual partners in type-specific HPV redetection. Given that persistent oncogenic HPV infections are associated with cancer-related outcomes, understanding the potential role of such factors in the pathogenesis of HPV-related outcomes is important.

High Frequency of Human Papillomavirus Detection in the Vagina Before First Vaginal Intercourse Among Females Enrolled in a Longitudinal Cohort Study

BACKGROUND Genital human papillomavirus (HPV) infection is believed to be primarily sexually transmitted. Few studies have documented the detection of HPV in the vagina before first vaginal intercourse. METHODS We used a longitudinally followed cohort of adolescent females without prior vaginal intercourse to examine the frequency of detection of vaginal HPV and the association between first reported HPV detection and noncoital sexual behaviors. RESULTS HPV was detected in 45.5% of subjects (10 of 22) before first vaginal sex. Seven of these 10 subjects reported noncoital behaviors that, in part, might have explained genital transmission. CONCLUSIONS HPV can be detected in the vagina before first sexual intercourse, highlighting the need for early vaccination.

Natural History of Multiple Human Papillomavirus Infections in Female Adolescents With Prolonged Follow-up

PURPOSE The aim of the study was to better characterize the natural history of human papillomavirus (HPV) infections in female adolescents. METHODS Female adolescents were enrolled in a longitudinal study. Self-vaginal samples were obtained every 3 months and tested for HPV. No participants received HPV vaccination. The findings for 40 female adolescents with the longest follow-up are reported in this study. RESULTS Average age at the time of enrollment was 15.2 years (range: 14-17; SD: .97). Mean duration of follow-up was 6.7 years (range: 4.4-9.2; SD: 1.2). In all, 32 participants (80%) reported being involved in sexual activity before their enrollment in the study; all reported being involved in sexual activity before enrollment; all reported being involved in sexual activity during follow-up. Baseline and cumulative prevalence of HPV among participants was 55% and 100%, respectively. During the study, each participant tested positive for a mean of 14 HPV types. Cumulatively, HPV 16 was detected in 29 of 40 participants (72.5%). Mean duration of high- and low-risk infections was 655.9 (median: 433) and 524.1 days (median: 334), respectively. CONCLUSION With prolonged follow-up, HPV infections with multiple types were found in all participants. Most had infection with HPV-16 or HPV-18, the oncogenic types represented in current vaccines, as well as infection with other oncogenic types. These data reinforce the importance of vaccine and non-vaccine strategies for prevention of HPV infections.