Hillard Weinstock

Sexually Transmitted Diseases Among American Youth: Incidence and Prevalence Estimates, 2000

CONTEXT In the United States, young people aged 15-24 represent 25% of the sexually experienced population. However, the incidence and prevalence of sexually transmitted diseases (STDs) among this age-group are unknown. METHODS Data from a variety of sources were used to estimate the incidence and prevalence of STDs among 15-24-year-olds in the United States in 2000. The quality and reliability of the estimates were categorized as good, fair or poor, depending on the quality of the data source. RESULTS Approximately 18.9 million new cases of STD occurred in 2000, of which 9.1 million (48%) were among persons aged 15-24. Three STDs (human papillomavirus, trichomoniasis and chlamydia) accounted for 88% of all new cases of STD among 15-24-year-olds. CONCLUSIONS These estimates emphasize the toll that STDs have on American youth. More representative data are needed to help monitor efforts at lowering the burden of these infections.

Sexually transmitted infections among US women and men: prevalence and incidence estimates, 2008.

Background Most sexually active people will be infected with a sexually transmitted infection (STI) at some point in their lives. The number of STIs in the United States was previously estimated in 2000. We updated previous estimates to reflect the number of STIs for calendar year 2008. Methods We reviewed available data and literature and conservatively estimated incident and prevalent infections nationally for 8 common STIs: chlamydia, gonorrhea, syphilis, herpes, human papillomavirus, hepatitis B, HIV, and trichomoniasis. Where available, data from nationally representative surveys such as the National Health and Nutrition Examination Survey were used to provide national estimates of STI prevalence or incidence. The strength of each estimate was rated good, fair, or poor, according to the quality of the evidence. Results In 2008, there were an estimated 110 million prevalent STIs among women and men in the United States. Of these, more than 20% of infections (22.1 million) were among women and men aged 15 to 24 years. Approximately 19.7 million incident infections occurred in the United States in 2008; nearly 50% (9.8 million) were acquired by young women and men aged 15 to 24 years. Human papillomavirus infections, many of which are asymptomatic and do not cause disease, accounted for most of both prevalent and incident infections. Conclusions Sexually transmitted infections are common in the United States, with a disproportionate burden among young adolescents and adults. Public health efforts to address STIs should focus on prevention among at-risk populations to reduce the number and impact of STIs.

The Epidemiology of Antiretroviral Drug Resistance among Drug-Naive HIV-1-Infected Persons in 10 US Cities

BACKGROUND The prevalence and characteristics of persons with newly diagnosed human immunodeficiency virus (HIV) infections with or without evidence of mutations associated with drug resistance have not been well described. METHODS Drug-naive persons in whom HIV had been diagnosed during the previous 12 months and who did not have acquired immune deficiency syndrome were sequentially enrolled from 39 clinics and testing sites in 10 US cities during 1997-2001. Genotyping was conducted from HIV-amplification products, by automated sequencing. For specimens identified as having mutations previously associated with reduced antiretroviral-drug susceptibility, phenotypic testing was performed. RESULTS Of 1311 eligible participants, 1082 (83%) were enrolled and successfully tested; 8.3% had reverse transcriptase or major protease mutations associated with reduced antiretroviral-drug susceptibility. The prevalence of these mutations was 11.6% among men who had sex with men but was only 6.1% and 4.7% among women and heterosexual men, respectively. The prevalence was 5.4% and 7.9% among African American and Hispanic participants, respectively, and was 13.0% among whites. Among persons whose sexual partners reportedly took antiretroviral medications, the prevalence was 15.2%. CONCLUSIONS Depending on the characteristics of the patients tested, HIV-genotype testing prior to the initiation of therapy would identify a substantial number of infected persons with mutations associated with reduced antiretroviral-drug susceptibility.

Estimating the Population Size of Men Who Have Sex with Men in the United States to Obtain HIV and Syphilis Rates

Background: CDC has not previously calculated disease rates for men who have sex with men (MSM) because there is no single comprehensive source of data on population size. To inform prevention planning, CDC developed a national population size estimate for MSM to calculate disease metrics for HIV and syphilis. Methods: We conducted a systematic literature search and identified seven surveys that provided data on same-sex behavior in nationally representative samples. Data were pooled by three recall periods and combined using meta-analytic procedures. We applied the proportion of men reporting same-sex behavior in the past 5 years to U.S. census data to produce a population size estimate. We then calculated three disease metrics using CDC HIV and STD surveillance data and rate ratios comparing MSM to other men and to women. Results: Estimates of the proportion of men who engaged in same-sex behavior differed by recall period: past year = 2.9% (95%CI, 2.6–3.2); past five years = 3.9% (3.5–4.4); ever = 6.9% (5.1–8.6). Rates on all 3 disease metrics were much higher among MSM than among either other men or women (38 to 109 times as high). Conclusions: Estimating the population size for MSM allowed us to calculate rates for disease metrics and to develop rate ratios showing dramatically higher rates among MSM than among other men or women. These data greatly improve our understanding of the disproportionate impact of these diseases among MSM in the U.S. and help with prevention planning.

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

Human Papillomavirus Infection and Cervical Cytology in Women Screened for Cervical Cancer in the United States, 2003–2005

248 million for chlamydia and

Age-Specific Seroprevalence of HIV, Hepatitis B Virus, and Hepatitis C Virus Infection Among Injection Drug Users Admitted to Drug Treatment in 6 US Cities

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

Trends in primary and secondary syphilis among men who have sex with men in the United States.

Some cervical cancer screening programs test for human papillomavirus (HPV) only after abnormal Papanicolaou (Pap) test results, whereas others perform both tests routinely and repeat testing if ei...

Neurosyphilis during the AIDS Epidemic, San Francisco, 1985–1992

OBJECTIVES This study measured age-specific seroprevalence of HIV, hepatitis B virus, and hepatitis C virus (HCV) infection among injection drug users (IDUs) admitted to drug treatment programs in 6 US cities. METHODS Remnant sera collected from persons entering treatment with a history of illicit drug injection were tested for antibodies to HIV, hepatitis C (anti-HCV), and hepatitis B core antigen (anti-HBc). RESULTS Prevalence of anti-HBc and anti-HCV increased with age and reached 80% to 100% among older IDUs in all 6 cities. Although overall age-specific HIV prevalence was lower than anti-HCV or anti-HBc, this prevalence was greater in the Northeast than in the Midwest and West. CONCLUSIONS The need continues for effective primary prevention programs among IDUs specifically targeting young persons who have recently started to inject drugs.

Genomic epidemiology of Neisseria gonorrhoeae with reduced susceptibility to cefixime in the USA: a retrospective observational study

OBJECTIVES We assessed the epidemiology of primary and secondary syphilis in the United States and estimated the percentages of cases occurring among men who have sex with men (MSM). METHODS We reviewed US syphilis surveillance data from 1990 through 2003. We estimated the number of cases occurring among MSM by modeling changes in the ratio of syphilis cases among men to cases among women. RESULTS During 1990 through 2000, the rate of primary and secondary syphilis decreased 90% overall, declining 90% among men and 89% among women. The overall rate increased 19% between 2000 and 2003, reflecting a 62% increase among men and a 53% decrease among women. In 2003, an estimated 62% of reported cases occurred among MSM. CONCLUSIONS Increasing syphilis cases among MSM account for most of the recent overall increase in rates and may be a harbinger of increasing rates of HIV infection among MSM. National efforts are under way to improve monitoring of syphilis trends, better understand factors associated with the observed increases, and improve efforts to prevent syphilis transmission.