Catherine Lindsey Satterwhite

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.

High Incidence of New Sexually Transmitted Infections in the Year following a Sexually Transmitted Infection: A Case for Rescreening

Context The Centers for Disease Control and Prevention recommends that women treated for Chlamydia trachomatis infection return in 3 months for evaluation of reinfection. Contribution When data from the RESPECT-2 trial were used, these investigators found that among patients treated for sexually transmitted infections, 25.8% of women and 14.7% of men acquired 1 or more new infections with Chlamydia trachomatis, Neisseria gonorrhoeae, or Trichomonas vaginalis during 1 year of follow-up. Approximately 66% of reinfections were asymptomatic. Implications Successful treatment of incident cases of sexually transmitted infections is unlikely to eliminate a reservoir of infection in the community. Physicians need to perform ongoing surveillance on men and women and encourage lifestyle changes in patients with reinfection. The Editors In 1985, the Centers for Disease Control and Prevention (CDC) treatment guidelines recommended that persons infected with Neisseria gonorrhoeae should return for a test of cure to be sure that the antibiotics had cured the infection (1). With new medications, treatment failure became rare, and by 1989, the guidelines suggested testing 1 to 2 months after treatment to detect treatment failure and reinfection (2). By 1993, the guidelines stated only that a test of cure was not recommended for N. gonorrhoeae (3). Test of cure has been unnecessary for Chlamydia trachomatis after treatment with first-line drugs, but infections detected among women several months after treatment have suggested that rescreening might be effective for detecting reinfection (3). Recent studies have found that 11% to 15% of women treated for C. trachomatis were infected when retested 3 to 4 months after treatment, possibly due to treatment failure, reinfection from an untreated partner, or infection from a new partner (46). New infections are often asymptomatic. One study with scheduled follow-up visits found that 62% of new C. trachomatis infections in men and in women were asymptomatic or unrecognized and would therefore probably be missed without rescreening (7). Untreated C. trachomatis infections can persist for years (8) and put infected women at risk for complications of asymptomatic pelvic inflammatory disease (9). In addition, transmission from asymptomatic persons may be responsible for most new infections in a community (10). The CDC has recommended that health care providers consider advising women with diagnoses of C. trachomatis infection to have another C. trachomatis test in 3 monthsnot as a test of cure but as a test for reinfection (11). We wondered whether men might also benefit from retesting, whether retesting should be expanded to include persons with N. gonorrhoeae or Trichomonas vaginalis infections (12), and whether there were other factors that clinicians could use to recommend retesting. We analyzed data from a large prevention counseling trial (13) that included baseline and 4 scheduled follow-up visits of patients in 3 sexually transmitted disease (STD) clinics to determine the incidence of new sexually transmitted infections during the year after a visit to the clinics. Methods A multicenter randomized, controlled trial of HIV prevention counseling with a rapid HIV test or a standard HIV test (RESPECT-2) was conducted in 3 public STD clinics in Denver, Colorado; Long Beach, California; and Newark, New Jersey. Primary analyses and detailed methods are described elsewhere (13). Briefly, eligible clients were those who came to the clinics for a full diagnostic examination for sexually transmitted infections, were HIV-negative at enrollment, reported having vaginal or anal sex in the preceding 3 months, and were 15 to 39 years of age. At the initial visit, participants were counseled, examined, and tested for sexually transmitted infections and HIV infection. Outcomes were measured at 13-week intervals, scheduled 3, 6, 9, and 12 months from the date of enrollment. Before each follow-up visit, study staff mailed a reminder letter to each participant and made a reminder telephone call. When participants did not keep appointments, staff mailed additional reminder letters and made additional telephone calls to reschedule the visit as needed. Participants who were due for a study follow-up visit were screened for sexually transmitted infections and were interviewed if they visited the clinic any time from 1 week before the due date up to 12 weeks after the due date. Participants were given

A public health focus on infertility prevention, detection, and management

25 for completing each follow-up visit. This amount was later increased to

Chlamydia trachomatis trends in the United States among persons 14 to 39 years of age, 1999-2008.

50 in an attempt to improve retention rates. Participants were tested for C. trachomatis, N. gonorrhoeae, and T. vaginalis infections at enrollment, at each quarterly follow-up visit, and at other visits not related to the study that occurred during the 12-month follow-up period (interim visits). An incident sexually transmitted infection was defined as a positive laboratory result either preceded by a negative result for the same infection or detected more than 14 days after provision of antibiotics effective against that infection. Testing was done in the local laboratories used by each clinic. Tests for C. trachomatis and N. gonorrhoeae infections were done on urine specimens by using nucleic acid amplification tests. The sensitivity and specificity values from the package inserts for these tests are cited here; the exact values are difficult to establish because there is no gold standard for identifying infected patients (14). The Long Beach and Newark clinics used ligase chain reaction (LCx Uriprobe, Abbott Diagnostics Division, Abbott Park, Illinois); the sensitivity and specificity for C. trachomatis were 93.1% and 97.1%, respectively, and the sensitivity and specificity for N. gonorrhoeae were 97.5% and 98.3%, respectively (15, 16). The Denver clinic used polymerase chain reaction initially (Cobas Amplicor, Roche Diagnostic Systems, Inc., Branchburg, New Jersey); the sensitivity and specificity for C. trachomatis were 93.4% and 96.7%, respectively, and the sensitivity and specificity for N. gonorrhoeae were 97.1% and 98.1%, respectively (17, 18). Eighteen months later, however, this clinic changed to using strand displacement amplification (BDProbeTec ET, BD Diagnostic Systems, Sparks, Maryland); the sensitivity and specificity for C. trachomatis were 90.7% and 96.6%, respectively, and the sensitivity and specificity for N. gonorrhoeae were 96.0% and 98.8%, respectively) (19). Trichomonas vaginalis was cultured by using the InPouch TV test (BioMed Diagnostics Inc., San Jose, California) or modified Diamond medium as the culture medium. The sensitivity has been estimated at 82.4% for the InPouch TV test and 87.8% for Diamond medium; specificity for both culture methods is nearly 100% (20). Cultures were done by using vaginal swab specimens from women. At follow-up visits, vaginal swabs were collected by the participant (Denver and Long Beach) or by a clinician (Newark), depending on local clinic policy. Behavioral data were collected by using Audio Computer-Assisted Self-Interview technology at enrollment and at each scheduled study follow-up visit. For most questions, a uniform 3-month recall period was used, regardless of the time since the most recent study visit. Because previous work has shown that most new infections are asymptomatic, we limited our analysis to participants who returned for testing and therefore could be classified as infected or not infected. Return visits with testing and interviews were scheduled every 3 months, and most participants returned within 2 weeks of their scheduled time. However, some participants also returned before their scheduled visit because of concern about a possible infection. Those who returned early were tested for sexually transmitted infections and were told to return for their scheduled visit for the interview and repeated testing. All test results from interim visits between 2 interviews were associated with behaviors reported during the next scheduled interview after the interim tests. Study interviews were conducted the first time the participant returned during the scheduled follow-up time (visit 1, 84 to 174 days; visit 2, 175 to 265 days; visit 3, 266 to 356 days; and visit 4, 357 to 448 days). Test data from participants who missed interviews were grouped in the analysis with their next interview. We excluded data from visits that occurred after participants missed 2 consecutive follow-up interviews. Men who reported having sex with men in the baseline interview were also excluded because of the small sample size. Person-years at risk were calculated by using the time between interviews. Participants could contribute up to 4 intervals of observation. Those who had multiple infections with the same organism in the same interval were only counted as having 1 infection, but if an infection recurred in a different interval it was counted again. We looked for 2 types of risk factors for infection. First, we looked for characteristics that clinicians could identify during a clinic visit that might predict infection at a subsequent visit. These factors included demographic characteristics, past risk behaviors, and infections detected during that visit. Second, we looked at events that might occur during follow-up that would alert patients to a need to return for testing for sexually transmitted infections. These factors included acquiring a new partner or having sex with more than 1 partner. Multivariate analysis of factors associated with sexually transmitted infection included serial measures for each participant. We performed unconditional logistic regression using generalized estimating equations, which accounted for within-participant correlations of repeated measures (21). Because this method assumes that missing data are missing completely at random, we assessed the relationship between missing visits and response variables for all 2419 participants included in our stu

Changes in Sexual Behavior and STD Prevalence Among Heterosexual STD Clinic Attendees: 1993-1995 Versus 1999-2000

In 2002, 2 million American women of reproductive age were infertile. Infertility is also common among men. The Centers for Disease Control and Prevention (CDC) conducts surveillance and research on the causes of infertility, monitors the safety and efficacy of infertility treatment, and sponsors national prevention programs. A CDC-wide working group found that, despite this effort, considerable gaps and opportunities exist in surveillance, research, communication, and program and policy development. We intend to consult with other federal agencies, professional and consumer organizations, the scientific community, the health care community, industry, and other stakeholders, and participate in the development of a national public health plan for the prevention, detection, and management of infertility.

Pelvic inflammatory disease among privately insured women, United States, 2001-2005.

Background: We report the first population-based assessment of national trends in chlamydia prevalence in the United States. Methods: We investigated trends in chlamydia prevalence in representative samples of the US population aged 14 to 39 years using data from five 2-year survey cycles of the National Health and Nutrition Examination Survey from 1999 to 2008. Prevalence estimates and 95% confidence intervals (CI) are reported stratified by age, gender, and race/ethnicity. Percent change in prevalence over this time period was estimated from regression models. Results: In the 2007–2008 cycle, chlamydia prevalence among participants aged 14 to 39 years was 1.6% (95% CI: 1.1%–2.4%). Prevalence was higher among females (2.2%, 95% CI: 1.4%–3.4%) than males (1.1%, 95% CI: 0.7%–1.7%). Prevalence among non-Hispanic black persons was 6.7% (95% CI: 4.6%–9.9%) and was 2.5% (95% CI: 1.6%–3.8%) among adolescents aged 14 to 19 years. Over the five 2-year cycles, there was an estimated 40% reduction (95% CI: 8%–61%) in prevalence among participants aged 14 to 39 years. Decreases in prevalence were notable in men (53% reduction, 95% CI: 19%–72%), adolescents aged 14 to 19 years (48% reduction, 95% CI: 11%–70%), and adolescent non-Hispanic black persons (45%, reduction, 95% CI: 4%–70%). There was no change in prevalence among females aged 14 to 25 years, the population targeted for routine annual screening. Conclusions: On the basis of population estimates of chlamydia prevalence, the overall chlamydia burden in the United States decreased from 1999 to 2008. However, there remains a need to reduce prevalence in populations most at risk and to reduce racial disparities.

Long-term trends in Chlamydia trachomatis infections and related outcomes in a U.S. managed care population.

Objective: To examine trends in sex behaviors and STD prevalence over time among heterosexual STD clinic populations from 3 urban STD clinics in the United States. Study Design: Cross-sectional analysis comparing baseline data on risk (self-reported) and STDs (laboratory defined) from 2 randomized controlled trials evaluating counseling efficacy conducted about 5 years apart, Project RESPECT (1993–1995) and RESPECT-2 (1999–2000). Results: The participants from RESPECT (n = 2457) and RESPECT-2 (n = 3080) were demographically similar. However, the proportion of participants reporting any unprotected anal sex was much higher in RESPECT-2 (women: 7% vs. 18%; men: 7% vs. 17%). Also, substantially more participants reported a new sex partner in RESPECT-2 (women: 43% vs. 61%; men: 54% vs. 72%). In addition, more women reported 2 or more partners (37% vs. 48%) and a partner with another concurrent sex partner (19% vs. 32%). Slightly more women and men in RESPECT-2 reported 2 protective behaviors, having an HIV test and any condom use; however, consistent condom use did not differ. Conversely, the proportion of participants with bacterial STDs (chlamydia, gonorrhea, or syphilis) was much lower in RESPECT-2 (women: 24% vs. 18%; men: 38% vs. 24%). Conclusions: Despite substantial promotion of safer sex behaviors over the past decade, many risk behaviors were stable over time, and some behaviors, such as unprotected anal sex, appeared substantially higher. Even in the absence of widespread behavior change, the prevalence of common bacterial STDs appeared to have decreased appreciably.

Estimates of Chlamydia trachomatis Infections Among Men: United States

Background: We explored the utility of using insurance claims data for surveillance of pelvic inflammatory disease (PID). PID rates are an important indicator of population level trends in reproductive morbidity; however, data available to monitor PID trends are limited. National survey data are currently used to estimate PID rates in the United States, but a declining number of cases threaten their future usefulness. Methods: We performed a retrospective analysis of PID diagnosis rates using administrative claims data from 2001 to 2005. Diagnostic codes were used to identify women aged 15 to 44 in the study population that were diagnosed with acute PID as inpatients, in emergency departments, and in outpatient ambulatory settings. Results: Rates of PID diagnoses among privately insured women declined significantly from 2001 to 2005 among all age groups examined and within all geographic regions. Annual PID diagnosis rates decreased from 317.0 to 236.0 per 100,000 enrollees, representing a 25.5% decline over the study period. The highest rates of PID were among 25- to 29-year-olds (352.8 per 100,000 in 2005) and among those residing in the South (314.3 per 100,000 in 2005). Most women (70.1%) received PID care through physician offices and other outpatient facilities; of these women, approximately 40% were treated by an obstetrician/gynecologist. Conclusions: The decline in PID diagnoses corresponds with previous reports from national surveys. Claims data offer a much needed new data source that will allow for continued monitoring of PID among a broad population in both inpatient and outpatient clinical settings.

Chlamydia Prevalence Among Women and Men Entering the National Job Training Program: United States, 2003―2007

Background: Given recent increasing case rates of Chlamydia trachomatis infection, we evaluated trends in chlamydia rates and related health outcomes in women and men aged 15 to 44 years who were enrolled in a Pacific Northwest health plan. Methods: We identified chlamydia, pelvic inflammatory disease (PID), ectopic pregnancy, and male urethritis cases occurring annually during 1997–2007 using computerized health plan databases, calculating rates per 100,000 person-years (py) by gender and 5-year age groups. We also calculated annual chlamydia testing rates. Results: In women, chlamydia testing rates increased by approximately 23% (220 tests per 1000 py in 1997 to 270 tests per 1000 in 2007). Chlamydia diagnosis rates rose from 449 cases/100,000 py in 1997 to 806/100,000 in 2007, a 79% increase (P = 0.01). Increases were greatest during 2005–2007, also the period of major conversion to nucleic acid amplification test. PID rates in this interval declined steadily from 823 cases/100,000 py to 473/100,000 (P < 0.01). Ectopic pregnancy rates remained unchanged. In men, chlamydia testing rates increased nearly 3.5-fold, from 12 to 42 tests per 1000 py. Chlamydia rates for men also rose significantly throughout the study interval (from 91 cases/100,000 py to 218/100,000; P < 0.01) as did urethritis diagnosis rates (P < 0.01). Conclusion: Between 1997 and 2007, annual health plan chlamydia rates increased significantly for both women and men. These trends may be due in part to increased testing rates and increased use of more sensitive tests, but they likely do not explain the increased urethritis rates. During this same interval, we observed steady declines in PID rates, consistent with other national data sources.

Chlamydia positivity trends among women attending family planning clinics: United States, 2004-2008.

Objective: To describe the epidemiology of genital Chlamydia trachomatis infections among men in the United States. Study Design: Data from the notifiable disease case surveillance system, the National Health and Nutrition Examination Survey (NHANES), the National Longitudinal Study of Adolescent Health (AddHealth), the National Job Training Program, the Men Having Sex with Men (MSM) Prevalence Monitoring Project, and adult and juvenile corrections facilities were used to summarize national chlamydia case and prevalence rates. Data were stratified by age and race/ethnicity. Results: In 2005, 232,781 chlamydia cases among men were reported, corresponding to a rate of 161.1 cases per 100,000 men, an increase of 43.5% compared with the case rate in 2001 (112.3). Population-based chlamydia prevalence rates from NHANES (1999–2002) were highest among men aged 20 to 29 years (3.2%); men aged 18 to 26 years participating in AddHealth (2001–2002) had a 3.7% prevalence rate. Rates were highest among black men in both NHANES (5.3%) and AddHealth (11.1%). The prevalence rate among men (aged 16–24 years) participating in the National Job Training Program was 8.1%. Among MSM, the 2005 median urethral chlamydia prevalence rate was 6%. Overall, chlamydia rates were highest in adult corrections facilities; the 2005 positivity rate among men aged 21 to 25 years was 7.8%. In juvenile corrections facilities, the 2005 positivity rate among men aged 15 to 17 years was 6.7%. Conclusions: Rates of genital C. trachomatis infections among men are persistently high, particularly among men entering the National Job Training Program and men in corrections facilities. The burden of disease is generally highest among young men and black men.