Sami L. Gottlieb

Global Estimates of the Prevalence and Incidence of Four Curable Sexually Transmitted Infections in 2012 Based on Systematic Review and Global Reporting.

Background Quantifying sexually transmitted infection (STI) prevalence and incidence is important for planning interventions and advocating for resources. The World Health Organization (WHO) periodically estimates global and regional prevalence and incidence of four curable STIs: chlamydia, gonorrhoea, trichomoniasis and syphilis. Methods and Findings WHO’s 2012 estimates were based upon literature reviews of prevalence data from 2005 through 2012 among general populations for genitourinary infection with chlamydia, gonorrhoea, and trichomoniasis, and nationally reported data on syphilis seroprevalence among antenatal care attendees. Data were standardized for laboratory test type, geography, age, and high risk subpopulations, and combined using a Bayesian meta-analytic approach. Regional incidence estimates were generated from prevalence estimates by adjusting for average duration of infection. In 2012, among women aged 15–49 years, the estimated global prevalence of chlamydia was 4.2% (95% uncertainty interval (UI): 3.7–4.7%), gonorrhoea 0.8% (0.6–1.0%), trichomoniasis 5.0% (4.0–6.4%), and syphilis 0.5% (0.4–0.6%); among men, estimated chlamydia prevalence was 2.7% (2.0–3.6%), gonorrhoea 0.6% (0.4–0.9%), trichomoniasis 0.6% (0.4–0.8%), and syphilis 0.48% (0.3–0.7%). These figures correspond to an estimated 131 million new cases of chlamydia (100–166 million), 78 million of gonorrhoea (53–110 million), 143 million of trichomoniasis (98–202 million), and 6 million of syphilis (4–8 million). Prevalence and incidence estimates varied by region and sex. Conclusions Estimates of the global prevalence and incidence of chlamydia, gonorrhoea, trichomoniasis, and syphilis in adult women and men remain high, with nearly one million new infections with curable STI each day. The estimates highlight the urgent need for the public health community to ensure that well-recognized effective interventions for STI prevention, screening, diagnosis, and treatment are made more widely available. Improved estimation methods are needed to allow use of more varied data and generation of estimates at the national level.

Risk of sequelae after Chlamydia trachomatis genital infection in women.

Chlamydia trachomatis infection, the most common reportable disease in the United States, can lead to pelvic inflammatory disease (PID), infertility, ectopic pregnancy, and chronic pelvic pain. Although C. trachomatis is identified among many women who receive a diagnosis of PID, the incidence and timing of PID and long-term sequelae from an untreated chlamydial infection have not been fully determined. This article examines evidence reviewed as part of the Centers for Disease Control and Prevention Chlamydia Immunology and Control Expert Advisory Meeting; 24 reports were included. We found no prospective studies directly assessing risk of long-term reproductive sequelae, such as infertility, after untreated C. trachomatis infection. Several studies assessed PID diagnosis after untreated chlamydial infection, but rates varied widely, making it difficult to determine an overall estimate. In high-risk settings, 2%-5% of untreated women developed PID within the approximately 2-week period between testing positive for C. trachomatis and returning for treatment. However, the rate of PID progression in the general, asymptomatic population followed up for longer periods appeared to be low. According to the largest studies, after symptomatic PID of any cause has occurred, up to 18% of women may develop infertility. In several studies, repeated chlamydial infection was associated with PID and other reproductive sequelae, although it was difficult to determine whether the risk per infection increased with each recurrent episode. The present review critically evaluates this body of literature and suggests future research directions. Specifically, prospective studies assessing rates of symptomatic PID, subclinical tubal damage, and long-term reproductive sequelae after C. trachomatis infection; better tools to measure PID and tubal damage; and studies on the natural history of repeated chlamydial infections are needed.

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.

Human papillomavirus vaccination practices: a survey of US physicians 18 months after licensure.

OBJECTIVES: The objectives of this study were to assess, in a nationally representative network of pediatricians and family physicians, (1) human papillomavirus (HPV) vaccination practices, (2) perceived barriers to vaccination, and (3) factors associated with whether physicians strongly recommended HPV vaccine to 11- to 12-year-old female patients. METHODS: In January through March 2008, a survey was administered to 429 pediatricians and 419 family physicians. RESULTS: Response rates were 81% for pediatricians and 79% for family physicians. Ninety-eight percent of pediatricians and 88% of family physicians were administering HPV vaccine in their offices (P < .001). Among those physicians, fewer strongly recommended HPV vaccination for 11- to 12-year-old female patients than for older female patients (pediatricians: 57% for 11- to 12-year-old patients and 90% for 13- to 15-year-old patients; P < .001; family physicians: 50% and 86%, respectively; P < .001). The most-frequently reported barriers to HPV vaccination were financial, including vaccine costs and insurance coverage. Factors associated with not strongly recommending HPV vaccine to 11- to 12-year-old female patients included considering it necessary to discuss sexuality before recommending HPV vaccine (risk ratio: 1.27 [95% confidence interval: 1.07–1.51]) and reporting more vaccine refusals among parents of younger versus older adolescents (risk ratio: 2.09 [95% confidence interval: 1.66–2.81]). CONCLUSIONS: Eighteen months after licensure, the vast majority of pediatricians and family physicians reported offering HPV vaccine. Fewer physicians strongly recommended the vaccine for younger adolescents than for older adolescents, and physicians reported financial obstacles to vaccination.

Longitudinal predictors of human papillomavirus vaccine initiation among adolescent girls in a high-risk geographic area.

Background: Human papillomavirus (HPV) vaccine uptake is low among adolescent girls in the United States. We sought to identify longitudinal predictors of HPV vaccine initiation in populations at elevated risk for cervical cancer. Methods: We interviewed a population-based sample of parents of 10- to 18-year-old girls in areas of North Carolina with elevated cervical cancer rates. Baseline interviews occurred in summer 2007 and follow-up interviews in fall 2008. Measures included health belief model constructs. Results: Parents reported that 27% (149/567) of their daughters had initiated HPV vaccine between baseline and follow-up. Of parents who at baseline intended to get their daughters the vaccine in the next year, only 38% (126/348) had done so by follow-up. Of parents of daughters who remained unvaccinated at follow-up but had seen a doctor since baseline, only 37% (122/388) received an HPV vaccine recommendation. Rates of HPV vaccine initiation were higher among parents who at baseline perceived lower barriers to getting HPV vaccine, anticipated greater regret if their daughters got HPV because they were unvaccinated, did not report “needing more information” as the main reason they had not already vaccinated, intended to get their daughters the vaccine, or were not born-again Christians. Conclusions: Missed opportunities to increase HPV vaccine uptake included unrealized parent intentions and absent doctor recommendations. While several health belief model constructs identified in early acceptability studies (e.g., perceived risk, perceived vaccine effectiveness) were not longitudinally associated with HPV vaccine initiation, our findings suggest correlates of uptake (e.g., anticipated regret) that offer novel opportunities for intervention.

Multistate outbreak of listeriosis linked to Turkey deli meat and subsequent changes in US regulatory policy

BACKGROUND Listeriosis, a life-threatening foodborne illness caused by Listeria monocytogenes, affects approximately 2500 Americans annually. Between July and October 2002, an uncommon strain of L. monocytogenes caused an outbreak of listeriosis in 9 states. METHODS We conducted case finding, a case-control study, and traceback and microbiological investigations to determine the extent and source of the outbreak and to propose control measures. Case patients were infected with the outbreak strain of L. monocytogenes between July and November 2002 in 9 states, and control patients were infected with different L. monocytogenes strains. Outcome measures included food exposure associated with outbreak strain infection and source of the implicated food. RESULTS Fifty-four case patients were identified; 8 died, and 3 pregnant women had fetal deaths. The case-control study included 38 case patients and 53 control patients. Case patients consumed turkey deli meat much more frequently than did control patients (P = .008, by Wilcoxon rank-sum test). In the 4 weeks before illness, 55% of case patients had eaten deli turkey breast more than 1-2 times, compared with 28% of control patients (odds ratio, 4.5; 95% confidence interval, 1.3-17.1). Investigation of turkey deli meat eaten by case patients led to several turkey processing plants. The outbreak strain was found in the environment of 1 processing plant and in turkey products from a second. Together, the processing plants recalled > 30 million pounds of products. Following the outbreak, the US Department of Agricultures Food Safety and Inspection Service issued new regulations outlining a L. monocytogenes control and testing program for ready-to-eat meat and poultry processing plants. CONCLUSIONS Turkey deli meat was the source of a large multistate outbreak of listeriosis. Investigation of this outbreak helped guide policy changes designed to prevent future L. monocytogenes contamination of ready-to-eat meat and poultry products.

Global Estimates of Prevalent and Incident Herpes Simplex Virus Type 2 Infections in 2012

Background Herpes simplex virus type 2 (HSV-2) infection causes significant disease globally. Adolescent and adult infection may present as painful genital ulcers. Neonatal infection has high morbidity and mortality. Additionally, HSV-2 likely contributes substantially to the spread of HIV infection. The global burden of HSV-2 infection was last estimated for 2003. Here we present new global estimates for 2012 of the burden of prevalent (existing) and incident (new) HSV-2 infection among females and males aged 15–49 years, using updated methodology to adjust for test performance and estimate by World Health Organization (WHO) region. Methods and Findings We conducted a literature review of HSV-2 prevalence studies world-wide since 2000. We then fitted a model with constant HSV-2 incidence by age to pooled HSV-2 prevalence values by age and sex. Prevalence values were adjusted for test sensitivity and specificity. The model estimated prevalence and incidence by sex for each WHO region to obtain global burden estimates. Uncertainty bounds were computed by refitting the model to reflect the variation in the underlying prevalence data. In 2012, we estimate that there were 417 million people aged 15–49 years (range: 274–678 million) living with HSV-2 infection world-wide (11.3% global prevalence), of whom 267 million were women. We also estimate that in 2012, 19.2 million (range: 13.0–28.6 million) individuals aged 15–49 years were newly-infected (0.5% of all individuals globally). The highest burden was in Africa. However, despite lower prevalence, South-East Asia and Western Pacific regions also contributed large numbers to the global totals because of large population sizes. Conclusions The global burden of HSV-2 infection is large, leaving over 400 million people at increased risk of genital ulcer disease, HIV acquisition, and transmission of HSV-2 to partners or neonates. These estimates highlight the critical need for development of vaccines, microbicides, and other new HSV prevention strategies.

Global and Regional Estimates of Prevalent and Incident Herpes Simplex Virus Type 1 Infections in 2012

Background Herpes simplex virus type 1 (HSV-1) commonly causes orolabial ulcers, while HSV-2 commonly causes genital ulcers. However, HSV-1 is an increasing cause of genital infection. Previously, the World Health Organization estimated the global burden of HSV-2 for 2003 and for 2012. The global burden of HSV-1 has not been estimated. Methods We fitted a constant-incidence model to pooled HSV-1 prevalence data from literature searches for 6 World Health Organization regions and used 2012 population data to derive global numbers of 0-49-year-olds with prevalent and incident HSV-1 infection. To estimate genital HSV-1, we applied values for the proportion of incident infections that are genital. Findings We estimated that 3709 million people (range: 3440–3878 million) aged 0–49 years had prevalent HSV-1 infection in 2012 (67%), with highest prevalence in Africa, South-East Asia and Western Pacific. Assuming 50% of incident infections among 15-49-year-olds are genital, an estimated 140 million (range: 67–212 million) people had prevalent genital HSV-1 infection, most of which occurred in the Americas, Europe and Western Pacific. Conclusions The global burden of HSV-1 infection is huge. Genital HSV-1 burden can be substantial but varies widely by region. Future control efforts, including development of HSV vaccines, should consider the epidemiology of HSV-1 in addition to HSV-2, and especially the relative contribution of HSV-1 to genital infection.

A pooled analysis of the effect of condoms in preventing HSV-2 acquisition.

BACKGROUND The degree of effectiveness of condom use in preventing the transmission of herpes simplex virus 2 (HSV-2) is uncertain. To address this issue, we performed a large pooled analysis. METHODS We identified prospective studies with individual-level condom use data and laboratory-defined HSV-2 acquisition. Six studies were identified through a review of publications through 2007: 3 candidate HSV-2 vaccine studies, an HSV-2 drug study, an observational sexually transmitted infection (STI) incidence study, and a behavioral STI intervention study. Study investigators provided us individual-level data to perform a pooled analysis. Effect of condom use was modeled using a continuous percentage of sex acts during which a condom was used and, alternatively, using absolute numbers of unprotected sex acts. RESULTS A total of 5384 HSV-2-negative people at baseline contributed 2 040 894 follow-up days; 415 persons acquired laboratory-documented HSV-2 during follow-up. Consistent condom users (used 100% of the time) had a 30% lower risk of HSV-2 acquisition compared with those who never used condoms (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.40-0.94) (P = .01). Risk for HSV-2 acquisition increased steadily and significantly with each unprotected sex act (HR, 1.16; 95% CI, 1.08-1.25) (P < .001). Condom effectiveness did not vary by gender. CONCLUSIONS To our knowledge, this is the largest analysis using prospective data to assess the effect of condom use in preventing HSV-2 acquisition. Although the magnitude of protection was not as large as has been observed with other STIs, we found that condoms offer moderate protection against HSV-2 acquisition in men and women.

Seroprevalence and Correlates of Herpes Simplex Virus Type 2 Infection in Five Sexually Transmitted–Disease Clinics

The seroprevalence of herpes simplex virus type 2 (HSV-2) infection was studied among 4128 patients from sexually transmitted disease (STD) clinics who were enrolled in a randomized controlled trial of human immunodeficiency virus and STD counseling efficacy. HSV-2 seroprevalence was 40.8% and was higher in women than in men (52.0% vs. 32.4%; P<.0001) and higher in blacks than in nonblacks (48.1% vs. 29.6%; P<.0001). Among 14-19-year-old patients, 36.8% of black women and 25.8% of nonblack women were infected with HSV-2. Independent predictors of HSV-2 seropositivity included female sex, black race, older age, less education, more lifetime sex partners, prior diagnosis of syphilis or gonorrhea, and lack of HSV-1 antibody. The majority of HSV-2-seropositive persons (84.7%) had never received a diagnosis of genital herpes. HSV-2 infection is common in STD clinic attendees in the United States, even among young age groups, especially among women. Efforts to prevent genital herpes should begin at an early age. The high rate of undiagnosed HSV-2 infection likely contributes to ongoing transmission.