Maya Sternberg

The prevalence of bacterial vaginosis in the United States, 2001-2004; associations with symptoms, sexual behaviors, and reproductive health

Objectives: Bacterial vaginosis (BV), a disturbance of vaginal microflora, is a common cause of vaginal symptoms and is associated with an increased risk of acquisition of sexually transmitted infections, HIV, and with adverse pregnancy outcomes. We determined prevalence and associations with BV among a representative sample of women of reproductive age in the United States. Study Design: Women aged 14–49 years participating in the National Health and Nutrition Examination Survey 2001–2004 were asked to submit a self-collected vaginal swab for Gram staining. BV, determined using Nugent’s score, was defined as a score of 7–10. Results: The prevalence of BV was 29.2% (95% confidence interval 27.2%–31.3%) corresponding to 21 million women with BV; only 15.7% of the women with BV reported vaginal symptoms. Prevalence was 51.4% among non-Hispanic blacks, 31.9% among Mexican Americans, and 23.2% among non-Hispanic whites (P <0.01 for each comparison). Although BV was also associated with poverty (P <0.01), smoking (P <0.05), increasing body mass index (&khgr;2P <0.0001 for trend), and having had a female sex partner (P <0.005), in the multivariate model, BV only remained positively associated with race/ethnicity, increasing lifetime sex partners (&khgr;2P <0.001 for trend), increasing douching frequency (&khgr;2P for trend <0.001), low educational attainment (P <0.01), and inversely associated with current use of oral contraceptive pills (P <0.005). Conclusion: BV is a common condition; 84% of women with BV did not report symptoms. Because BV increases the risk of acquiring sexually transmitted infections, BV could contribute to racial disparities in these infections.

Prevalence of Sexually Transmitted Infections Among Female Adolescents Aged 14 to 19 in the United States

OBJECTIVE: Most young women initiate sexual activity during adolescence; risk for sexually transmitted infections (STIs) accompanies this initiation. In this study we estimated the prevalence of the most common STIs among a representative sample of female adolescents in the United States. METHODS: Data were analyzed from 838 females who were aged 14 to 19 and participating in the nationally representative National Health and Nutrition Examination Survey 2003–2004. After interview and examination, survey participants provided biological specimens for laboratory testing. The main outcome was weighted prevalence of at least 1 of 5 STIs: Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, herpes simplex virus type 2, and human papillomavirus (HPV) (any of 23 high-risk types or type 6 or 11). RESULTS: Prevalence of any of the 5 STIs was 24.1% among all and 37.7% among sexually experienced female adolescents. HPV (23 high-risk types or type 6 or 11) was the most common STI among all female adolescents (prevalence: 18.3%), followed by C trachomatis infection (prevalence: 3.9%). Prevalence of any of the STIs was 25.6% among those whose age was the same or 1 year greater than their age at sexual initiation and 19.7% among those who reported only 1 lifetime sex partner. CONCLUSIONS: The prevalence of STIs among female adolescents is substantial, and STIs begin to be acquired soon after sexual initiation and with few sex partners. These findings support early and comprehensive sex education, routine HPV vaccination at the age of 11 to 12 years, and C trachomatis screening of sexually active female adolescents.

The Prevalence of Trichomonas vaginalis Infection among Reproductive-Age Women in the United States, 2001–2004

BACKGROUND Trichomonas vaginalis infection is a common sexually transmitted protozoal infection and is associated with several adverse health outcomes, such as preterm birth, delivery of a low-birth weight infant, and facilitation of sexual transmission of human immunodeficiency virus. The annual incidence in the United States has been estimated to be 3-5 million cases. However, there are no data on the prevalence of trichomoniasis among all reproductive-age women. We estimated the prevalence of T. vaginalis infection from a nationally representative sample of women in the United States. METHODS Women aged 14-49 years who participated in the National Health and Examination Survey cycles for 2001-2004 provided self-collected vaginal swab specimens. The vaginal fluids extracted from these swabs were evaluated for the presence of T. vaginalis using polymerase chain reaction. RESULTS Overall, 3754 (81%) of 4646 women provided swab specimens. The prevalence of T. vaginalis infection was 3.1% (95% confidence interval [CI], 2.3%-4.3%); for non-Hispanic white women, it was 1.3% (95% CI, 0.7%-2.3%); for Mexican American women, it was 1.8% (95% CI, 0.9%-3.7%); and for non-Hispanic black women, it was 13.3% (95% CI, 10.0%-17.7%). Factors that remained associated with increased likelihood of T. vaginalis infection in multivariable analyses included non-Hispanic black race/ethnicity, being born in the United States, a greater number of lifetime sex partners, increasing age, lower educational level, poverty, and douching. CONCLUSIONS The prevalence of T. vaginalis infection among women in the United States was 3.1%. A significant racial disparity exists; the prevalence among non-Hispanic black women was 10.3 times higher than that among non-Hispanic white and Mexican American women. Optimal prevention and control strategies for T. vaginalis infection should be explored as a means of closing the racial disparity gaps and decreasing adverse health outcomes due to T. vaginalis infection.

Prevalence of Genital Human Papillomavirus Among Females in the United States, the National Health and Nutrition Examination Survey, 2003–2006

BACKGROUND Genital human papillomaviruses (HPV) include >40 sexually transmitted viruses. Most HPV infections do not progress to disease, but infection with certain types of HPV can cause cervical and other anogenital and oropharyngeal cancer, and other types of HPV are associated with anogenital warts. HPV vaccines prevent infection with HPV 16 and 18, which account for 70% of cases of cervical cancer, and HPV 6 and 11, which cause 90% of the cases of anogenital warts. METHODS Using data and self-collected cervicovaginal specimens from 4150 females, 14-59 years of age, from consecutive National Health and Nutrition Examination Surveys (2003-2006), we estimated the prevalence of type-specific HPV DNA and examined sociodemographic and sexual determinants. RESULTS The overall prevalence of HPV was 42.5% in females 14-59 years of age and varied significantly by age, race or ethnicity, and number of sex partners. Individual type prevalence was less than 7%, ranging from <0.5% through 6.5%. The most common type was nononcogenic HPV 62 (found in 6.5% of subjects), followed by HPV 53 and HPV 16 (4.7%), both of which are oncogenic types. The most prevalent species was nononcogenic α3. CONCLUSIONS HPV infection is common among US females, with the highest burden of infection found in young females 20-24 years of age. Monitoring trends in HPV type distribution will contribute to our understanding of the early impact of HPV vaccines.

Gonorrhea and chlamydia in the United States among persons 14 to 39 years of age, 1999 to 2002

Context Accurate information about the prevalence of sexually transmitted diseases is essential to the development of screening programs that effectively reduce disease burden. Contribution These data from the 19992002 National Health and Nutrition Examination Survey estimate the prevalence of gonorrhea and chlamydia among the U.S. population age 14 to 39 years to be 0.24% and 2.2%, respectively. Chlamydia prevalence was highest among younger women and persons with a history of gonorrhea or chlamydia infection. Cautions Although these are the most recently available data, they are more than 5 years old and did not permit estimation of prevalence by geographic region. Implication These data support current screening and treatment recommendations for chlamydia. The Editors Genital infections with Chlamydia trachomatis and Neisseria gonorrhoeae are important causes of cervicitis and urethritis, as well as pelvic inflammatory disease, ectopic pregnancy, chronic pelvic pain, and infertility, among women (1). In addition, nonulcerative sexually transmitted diseases (STDs), including chlamydia and gonorrhea, induce anogenital inflammation and can facilitate HIV infection (2). Chesson and colleagues (3) estimated total direct medical costs of

Seroprevalence of Human Papillomavirus Type 16 Infection in the United States

248 million for chlamydia and

Patient-delivered partner treatment with azithromycin to prevent repeated Chlamydia trachomatis infection among women: A randomized, controlled trial

77 million for gonorrhea in 2000 among persons age 15 to 24 years. Chlamydia trachomatis infection is the most commonly reported nationally notifiable disease in the United States, with more than 900000 cases reported to state and local health departments in 2005. The second most commonly reported disease is N. gonorrhoeae, with more than 330000 cases reported in 2005 (4). Reported cases represent a partial index of disease burden from chlamydial and gonorrheal infection because many cases are asymptomatic and are not detected. On the basis of reported cases, persons 14 to 39 years of age account for more than 95% of chlamydial cases and more than 90% of gonorrheal cases in the United States (4). To our knowledge, the following report is the most comprehensive description of national disease burden from chlamydia and gonorrhea with results of C. trachomatis and N. gonorrhoeae testing from a representative sample of the civilian noninstitutionalized U.S. population age 14 to 39 years in the National Health and Nutrition Examination Survey (NHANES), 19992002. Methods Survey Design The NHANES is a series of cross-sectional surveys designed to provide national statistics on the health and nutritional status of the general household population through household interviews, standardized physical examinations, and the collection of biological samples in special mobile examination centers. In 1999, NHANES became a continuous survey, with data released every 2 years. The sampling plan of the survey is a stratified, multistage, probability cluster design that selects a sample representative of the U.S. civilian noninstitutionalized population. Data presented in this paper are from the 19992002 survey years. (Additional years of data on gonorrhea and chlamydia were collected in the NHANES survey for the 20032004 cycle, but testing was performed by using a different laboratory test, the Becton Dickinson ProbeTec [Becton Dickinson, Franklin Lakes, New Jersey], owing to the discontinuation of the Abbott LCx [Abbott Laboratories, Abbott Park, Illinois]. Disclosure risks with the NHANES 20032004 gonorrhea data led the National Center for Health Statistics, Centers for Disease Control and Prevention [CDC], to withhold the release of the gonorrhea data for public use. The chlamydia data did not demonstrate any disclosure risks, but because a different laboratory test was used, we felt it prudent to publish data through 2002 only. Once the 20052006 data are available for gonorrhea and chlamydia, the 20032004 data can be better assessed and a data update through 2006 can be published [20052006 data are anticipated to be released in mid- to late 2008 if no quality control issues arise].) Our sample includes 6632 participants, age 14 to 39 years, who were sampled from randomly selected U.S. locations. Adolescents (age 14 to 17 years), African Americans, and Mexican Americans were oversampled to improve precision of estimates for these subgroups. Race or ethnic group was categorized on the basis of the participants self-reported information as non-Hispanic white, non-Hispanic black, or Mexican American. Participants who did not fit into 1 of these categories were classified as other and were analyzed with the total sample but not in race or ethnic subgroups. All participants provided written informed consent. For minors (age <18 years), parents gave written consent, accompanied by the minors assent. An institutional review board at CDC reviewed and approved the study protocol. Sexual behavior data were collected in the mobile examination center during a private, audio, computer-assisted, self-interview. Sex was defined as vaginal, oral, or anal intercourse. In our analyses, we defined sexually experienced as reporting ever having had sex. Questions about history of gonorrhea and chlamydia diagnoses were asked only of sexually experienced persons 18 to 39 years of age. All NHANES participants who were tested for C. trachomatis and N. gonorrhoeae were given an opportunity to obtain their test results by telephone by using a confidential identification number. Reminder letters were sent to adults, and telephone calls were made to minors to encourage participants to call to learn about their test results. Laboratory Testing Urine specimens collected from participants were processed in the mobile examination center and shipped to CDC for C. trachomatis and N. gonorrhoeae testing by using a ligase chain reaction assay (LCx, Abbott Laboratories), according to the manufacturers instructions. Although it is not recommended for routine clinical practice, specimens positive for C. trachomatis or N. gonorrhoeae were retested from the original urine specimen by using the same assay for detection for the purposes of this survey. No retests yielded discrepant results. Specimens with negative results were not retested. After completion of data collection, Abbott Laboratories issued a recall for certain lots of N. gonorrhoeae LCx assay kits in 2002 (5). No affected lots were used in our survey. Abbott Laboratories discontinued marketing of both the N. gonorrhoeae and C. trachomatis LCx assay kits in 2003. In a letter to its customers, dated 10 January 2003, the manufacturer stated that discontinuation of the product was due to manufacturing issues. Statistical Analysis We performed statistical analyses by using SAS for Windows software, version 9.1 (SAS Institute, Cary, North Carolina), and SAS-callable SUDAAN (RTI, Research Triangle Park, North Carolina). Analyses performed with SUDAAN accounted for the complex survey design by incorporating the survey weights and using a Taylor series linearization to calculate variance estimates (6). Data were weighted to account for the unequal probability of selection and nonresponse to the interview and examination. We estimated the number of infections in the population by multiplying the 2000 U.S. Census figures for the noninstitutionalized civilian U.S. population (7) age 14 to 39 years by the weighted prevalence estimate. We calculated 95% CIs for the prevalence estimates by using a log transformation. We performed significance tests for the association between chlamydia and gonorrhea and other variables by using a chi-square statistic. The chi-square statistic was based on a test for no interaction in a log-linear model that was fit to the log of the estimated cell proportions (LLCHISQ test statistic in SUDAAN). We used logistic regression to test for the presence of a linear trend across the categories of an independent variable. We considered P values of 0.05 or less to be statistically significant. No adjustments were made for multiple comparisons. We computed the relative standard errors for each weighted estimate. The relative standard error summarizes how large the sampling variability is relative to the size of the point estimatethe higher the relative standard error, the less reliable the estimate. Relative standard errors greater than 30% are considered to be unstable and should be interpreted with caution. We performed logistic regression to identify the variables that were associated with C. trachomatis infection (logistic regression was not performed with N. gonorrhoeae infection as the outcome because of the small number of infected respondents). Survey variables associated with infection in the medical literature were considered for entry into our model. We included interview and mobile examination center data in the model only if the question had been asked of all persons age 14 to 39 years in the survey (for example, questions of history of gonorrhea or chlamydia diagnosis were not included). We included sex, age, and number of lifetime sexual partners in the model regardless of statistical significance on the basis of well-established epidemiologic evidence that these are important factors associated with chlamydia. This was followed by adding variables in order of statistical significance by using a step-up approach to the baseline model. The criteria for the variable to remain in the model were based on a P value of 0.05 or less (by Satterwaithe adjusted F test). Once all variables added into the baseline model were statistically significant and no further variables met the entry criteria, we reassessed all variables excluded from the model for data-based confounding. We entered each excluded variable individually into the model and retained it if any variable estimate changed by more than 30%. Once a model with all relevant main effects was selected, we evaluated all pairwise interactions. Pairwise interactions between sex and each variable in the model allowed us to explore whether any of the main effects differed betw

Seroprevalence and Coinfection with Herpes Simplex Virus Type 1 and Type 2 in the United States, 1988–1994

Infection with human papillomavirus (HPV) type 16 accounts for about half of cervical cancers worldwide. This study investigated the seroepidemiology of HPV-16 infection in the United States by using a population-based survey. Serum samples and questionnaire data were collected from 1991 to 1994 for the National Health and Nutrition Examination Surveys. HPV-16-specific IgG antibody was detected by use of an HPV-16 virus-like particle ELISA. HPV-16 seropositivity in the US population aged 12-59 years was 13.0% (95% confidence interval, 11.5%-14.7%). Seroprevalence was higher in women (17.9%) than in men (7.9%). Age, race/ethnicity, and number of lifetime sex partners were associated with HPV seropositivity in women. Race/ethnicity, age at first intercourse, urban/nonurban residence, years of sexual activity, and having had sex with a man were associated with HPV seropositivity in men. Information on HPV-16 seroepidemiology will be important for designing prevention efforts including vaccine programs.

Seroprevalence of Human Papillomavirus Types 6, 11, 16, and 18 in the United States: National Health and Nutrition Examination Survey 2003–2004

Background Repeated infection with Chlamydia trachomatis increases the risk for serious sequelae: pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain. A substantial proportion of women treated for C trachomatis infection are reinfected by an untreated male sex partner in the first several months after treatment. Effective strategies to ensure partner treatment are needed. Goal The goal of the study was to determine whether repeated infections with C trachomatis can be reduced by giving women doses of azithromycin to deliver to male sex partners. Study Design A multicenter randomized controlled trial was conducted among 1787 women aged 14 to 34 years with uncomplicated C trachomatis genital infection diagnosed at family planning, adolescent, sexually transmitted disease, and primary care clinics or emergency or other hospital departments in five US cities. Women treated for infection were randomized to one of two groups: patient-delivered partner treatment (in which they were given a dose of azithromycin to deliver to each sex partner) or self-referral (in which they were asked to refer their sex partners for treatment). The main outcome measure was C trachomatis DNA detected by urine ligase chain reaction (LCR) or polymerase chain reaction (PCR) by 4 months after treatment. Results The characteristics of study participants enrolled in each arm were similar except for a small difference in the age distribution. Risk of reinfection was 20% lower among women in the patient-delivered partner treatment arm (87/728; 12%) than among those in the self-referral arm (106/726; 15%); however, this difference was not statistically significant (odds ratio, 0.80; 95% confidence interval, 0.62–1.05;P = 0.102). Women in the patient-delivered partner treatment arm reported high compliance with the intervention (82%). Conclusion Patient-delivered partner treatment for prevention of repeated C trachomatis infection among women is comparable to self-referral and may be an appropriate option for some patients.

Genital warts among 18- to 59-year-olds in the United States, national health and nutrition examination survey, 1999--2004.

Seroprevalence of and coinfection with herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in the United States were analyzed by use of data from a nationally representative survey (National Health and Nutrition Examination Survey III, 1988-1994). Evidence was explored for possible protection by prior HSV-1 infection against infection and clinical disease with HSV-2. Overall, 27.1% of persons aged > or =12 years were seronegative for HSV-1 and HSV-2; 51.0% were seropositive for HSV-1 only, 5.3% for HSV-2 only, and 16.6% for both HSV-1 and HSV-2. The seroprevalence of HSV-2 was higher in persons with HSV-1 antibody. Approximately 76% of persons who had HSV-2 antibody also had HSV-1 antibody. Persons seropositive for HSV-2 only reported a history of genital herpes more frequently (16.2%) than persons seropositive for both HSV-1 and HSV-2 (5.9%). The seroprevalence of HSV-1 and age at infection may influence the epidemiology of clinical genital herpes, even if prior HSV-1 infection does not prevent HSV-2 infection.