The clinical and economic consequences of screening young men for genital chlamydial infection

Evaluation of Chlamydia trachomatis screening from the perspective of health economics: a systematic review

Background

Most Chlamydia trachomatis (CT) infections are asymptomatic. The infection can persist and lead to severe sequelae. Therefore, screening for CT can primarily prevent serious sequelae.

Aim

To systematically evaluate CT screening from the perspective of health economics, summarize previous findings from different target populations, and make practical recommendations for developing local CT screening strategies.

Methods

PubMed, Web of Science, Embase, Cochran Library, and National Health Service Economic Evaluation Database (Ovid) were searched from January 1, 2000, to March 4, 2023. Studies reporting the cost-effectiveness, cost-benefit, or cost-utility of CT screening were eligible to be included. A narrative synthesis was used to analyze and report the results following the PRISMA guidelines. The Consensus on Health Economic Criteria (CHEC) list was used to assess the methodological quality of included studies.

Results

Our review finally comprised 39 studies addressing four populations: general sexually active people (n = 25), pregnant women (n = 4), women attending STD and abortion clinics (n = 4), and other high-risk individuals (n = 6). The total number of participants was ~7,991,198. The majority of studies assessed the cost-effectiveness or cost-utility of the screening method. The results showed that the following screening strategies may be cost-effective or cost-saving under certain conditions: performing CT screening in young people aged 15-24 in the general population, military recruits, and high school students; incorporating CT screening into routine antenatal care for pregnant women aged 15-30; opportunistic CT screening for women attending STD and abortion clinics; home-obtained sampling for CT screening using urine specimens or vaginal swab; performing CT screening for 14-30-year-old people who enter correctional institutions (i.e., jail, detention) as soon as possible; providing CT screening for female sex workers (FSWs) based on local incidence and prevalence; adding routine CT screening to HIV treatment using rectal samples from men who have sex with men (MSM).

Conclusion

We found that CT screening in general sexually active people aged 15-24, military recruits, high school students, pregnant women aged 15-30, women attending STD and abortion clinics, people entering jail, detention, FSWs, and MSM has health economic value. Due to the different prevalence of CT, diversities of economic conditions, and varying screening costs among different populations and different countries, regions, or settings, no uniform and standard screening strategies are currently available. Therefore, each country should consider its local condition and the results of health economic evaluations of CT screening programs in that country to develop appropriate CT screening strategies.

Estimated costs and quality-adjusted life-years lost due to N. gonorrhoeae infections acquired in 2015 in the United States: A modelling study of overall burden and disparities by age, race/ethnicity, and other factors

Background

Disparities in the health and economic burden of gonorrhoea have not been systematically quantified. We estimated population-level health losses and costs associated with gonococcal infection and sequelae in the United States.

Methods

We used probability-tree models to capture gonorrhoea sequelae and to estimate attributable disease burden in terms of the discounted lifetime costs and quality-adjusted life-years (QALYs) lost due to incident infections acquired during 2015 from the healthcare system perspective. Numbers of infections in 2015 were obtained from a published gonorrhoea transmission model. We evaluated population-level disease burden, disaggregated by sex, age, race/ethnicity, and for men who have sex with men (MSM). We conducted a multivariate sensitivity analysis for key parameters.

Findings

Discounted lifetime QALYs lost per incident gonococcal infection were estimated as 0.093 (95% uncertainty interval [UI] 0.022-0.22) for women, 0.0020 (0.0015-0.0024) for heterosexual men, and 0.0015 (0.00070-0.0021) for MSM. Discounted lifetime costs per incident infection were USD 261 (109-480), 169 (88-263), and 133 (50-239), respectively. At the population level, total discounted lifetime QALYs lost due to infections acquired during 2015 were 53,293 (12,326-125,366) for women, 621 (430-872) for heterosexual men, and 1,078 (427-1,870) for MSM. Total discounted lifetime costs were USD 150 million (64-277 million), 54 million (25-92 million), and 97 million (34-197 million), respectively. The highest total burden of both QALYs and costs at the population-level was observed in Non-Hispanic Black women, and highest burden per 1,000 person-years was identified in MSM among men and American Indian/Alaska Native among women.

Interpretation

Gonorrhoea causes substantial health losses and costs in the United States. These results can inform planning and prioritization of prevention services.

Funding

Centers for Disease Control and Prevention, Charles A. King Trust.

Project RedDE: Cluster Randomized Trial to Reduce Missed or Delayed Abnormal Laboratory Value Actions

Supplemental Digital Content is available in the text.

Failure of timely abnormal laboratory result follow-up is relatively common and may lead to harm. This study hypothesized that a quality improvement collaborative (QIC) could reduce the frequency of missed or delayed action on abnormal laboratory values.

The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis

BACKGROUND AND OBJECTIVES

The evidence base supporting the National Chlamydia Screening Programme, initiated in 2003, has been questioned repeatedly, with little consensus on modelling assumptions, parameter values or evidence sources to be used in cost-effectiveness analyses. The purpose of this project was to assemble all available evidence on the prevalence and incidence of Chlamydia trachomatis (CT) in the UK and its sequelae, pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI) to review the evidence base in its entirety, assess its consistency and, if possible, arrive at a coherent set of estimates consistent with all the evidence.

METHODS

Evidence was identified using 'high-yield' strategies. Bayesian Multi-Parameter Evidence Synthesis models were constructed for separate subparts of the clinical and population epidemiology of CT. Where possible, different types of data sources were statistically combined to derive coherent estimates. Where evidence was inconsistent, evidence sources were re-interpreted and new estimates derived on a post-hoc basis.

RESULTS

An internally coherent set of estimates was generated, consistent with a multifaceted evidence base, fertility surveys and routine UK statistics on PID and EP. Among the key findings were that the risk of PID (symptomatic or asymptomatic) following an untreated CT infection is 17.1% [95% credible interval (CrI) 6% to 29%] and the risk of salpingitis is 7.3% (95% CrI 2.2% to 14.0%). In women aged 16-24 years, screened at annual intervals, at best, 61% (95% CrI 55% to 67%) of CT-related PID and 22% (95% CrI 7% to 43%) of all PID could be directly prevented. For women aged 16-44 years, the proportions of PID, EP and TFI that are attributable to CT are estimated to be 20% (95% CrI 6% to 38%), 4.9% (95% CrI 1.2% to 12%) and 29% (95% CrI 9% to 56%), respectively. The prevalence of TFI in the UK in women at the end of their reproductive lives is 1.1%: this is consistent with all PID carrying a relatively high risk of reproductive damage, whether diagnosed or not. Every 1000 CT infections in women aged 16-44 years, on average, gives rise to approximately 171 episodes of PID and 73 of salpingitis, 2.0 EPs and 5.1 women with TFI at age 44 years.

CONCLUSIONS AND RESEARCH RECOMMENDATIONS

The study establishes a set of interpretations of the major studies and study designs, under which a coherent set of estimates can be generated. CT is a significant cause of PID and TFI. CT screening is of benefit to the individual, but detection and treatment of incident infection may be more beneficial. Women with lower abdominal pain need better advice on when to seek early medical attention to avoid risk of reproductive damage. The study provides new insights into the reproductive risks of PID and the role of CT. Further research is required on the proportions of PID, EP and TFI attributable to CT to confirm predictions made in this report, and to improve the precision of key estimates. The cost-effectiveness of screening should be re-evaluated using the findings of this report.

FUNDING

The Medical Research Council grant G0801947.

The prevalence of Chlamydia trachomatis in the population living in Roma settlements: a comparison with the majority population

BACKGROUND

We aimed to study the occurrence of Chlamydia trachomatis infection in the population living in Roma settlements and to compare the obtained results with the prevalence in the majority population.

METHODS

We examined 340 people for the presence of bacterium C. trachomatis, 208 of them were Roma (66 men, 142 women) and 132 were from the majority population (75 men, 57 women). Respondents were aged 18-55 years (mean age = 33.44, STD = 9.57). The occurence of C. trachomatis was detected by direct proof of the pathogen by polymerase chain reaction (PCR).

RESULTS

Of 340 respondents included in the study, 22 (6.5%) showed positivity for C. trachomatis infection, 15 of them were Roma (7.2%) and 7 non-Roma (5.3%). The highest positivity was detected in Roma women (8.5%), while positivity in both non-Roma women and men was 5.3%, and in Roma men 4.5%. We did not confirm any significant contribution of age, gender or ethnicity to the occurrence of C. trachomatis infection.

CONCLUSIONS

Despite the increased number of people with risk factors in the Roma community, no significant difference in the occurrence of C. trachomatis infection was found. Neither age nor gender contributes to the probability of C. trachomatis infection. Nevertheless, there are other health consequences which might be more pronounced among the population living in Roma settlements due to barriers to the health care and their lower ability to benefit from health care services provided.

Mixture-of-exponentials models to explain heterogeneity in studies of the duration of Chlamydia trachomatis infection

Published studies of the duration of asymptomatic Chlamydia trachomatis infection in women have produced diverse estimates, and most reviewers have not attempted an evidence synthesis. We review the designs of duration studies, distinguishing between the incident cases presenting soon after infection in clinic-based studies and prevalent cases ascertained in population screening studies. We combine evidence from all studies under fixed-effect (single clearance rate), random-effect (study-specific clearance rate), and mixture-of-exponentials models, in which there are either two or three classes of infection that clear at different rates. We can identify classes as 'passive' infection and fast-clearing and slow-clearing infections. We estimate models by Bayesian MCMC and compared them using posterior mean residual deviance and the deviance information criterion. The single fixed-effect clearance rate model fitted very poorly. The random-effect model was adequate but inferior to the two-class and three-class mixture of exponentials. According to the two-class model, the proportion in the first class was 23% (95% CI: 16-31%), and the mean duration of C. trachomatis infection is 1.36 years (95% CI: 1.13-1.63 years). With the three-rate model, duration was similar, but identification of the proportions in each class (19%, 31%, and 49%) was poor. Although the random-effect model was descriptively adequate, the extreme degree of between-study variation in the clearance rate it predicted lacked biological plausibility. Differences in study recruitment and sampling mechanisms, acting through a mixture-of-exponentials model, better explains the apparent heterogeneity in duration.

Use of the internet and self-collected samples as a sexually transmissible infection intervention in rural Illinois communities

BACKGROUND

In the USA, reported cases of chlamydia (Chlamydia trachomatis) continue to rise despite substantial funding for screening. National gonorrhoea (Neisseria gonorrhoeae) rates have remained relatively stable, with clusters associated with metropolitan areas. Rural areas are no exception, as every county in Illinois reported cases of chlamydia in 2007. Morbidity associated with infection remains a public health concern, with costs of $US2.5+ billion annually. Novel screening interventions must be examined for their ability to reach those at risk who are missed by traditional methods.

METHODS

The website Iwantthekit.org was modified to allow residents from 25 contiguous counties in Central Illinois to request a self-collected sample kit. Returned kits were tested for chlamydia and gonorrhoea. The initial study period was 12 months.

RESULTS

During the study period, 343 kits were requested from 20 counties and 39.9% were satisfactorily returned for analysis. Positivity rates for chlamydia and gonorrhoea were 5.8% and 1.2%, respectively, for females and 1.9% and 0% for males. Males comprised 37.7% of all internet samples (compared with 23.4% for traditional screening venues) and 40.4% of all internet samples submitted by whites (compared with only 17.2% of traditional screening).

CONCLUSIONS

The female positivity rate was comparable to those seen in other screening venues and the method successfully engaged at-risk males. Overall, participation was low and the costs associated with the program outweighed the averted costs associated with the few cases identified. While this methodology resulted in sample requests from a wide area, it must be utilised by more individuals to become cost-effective.

Development and Evaluation of GIS-Based Chlamydia Trachomatis Intervention Policy in Illinois

Chlamydia trachomatis is the most prevalent infectious disease in the United States. Complications include pelvic inflammatory disease (PID), ectopic pregnancy, and infertility. The cost of PID in 1998 was estimated at greater than $1.9 billion. Screening intervention strategies are often consumed by those at low risk. The objective of this study is the development of a more cost-effective intervention strategy by employing Geographic Information Systems and Census Bureau demographic data in selected Local Health Departments in Illinois. Case studies of intervention activities at the state and local level were performed. An evaluability assessment model of current inputs, processes and outcomes was created. A proposed model utilizing additional state inputs was developed and tested. Interventions were evaluated for effectiveness in reducing the incidence of Chlamydia trachomatis. Societal cost effectiveness analysis was also performed. The proposed model was tested in 2006. Results indicate that only minimal changes in annual incidence are required for GIS-augmented interventions to be cost-effective.

Urine‐based testing forChlamydia trachomatisusing polymerase chain reaction, leucocyte esterase and urethral and cervical smears

The performance of Roche polymerase chain reaction (PCR) Amplicor to detect Chlamydia trachomatis in first-voided urine specimens from 422 males and 456 females attending two clinics for sexually transmitted infections was evaluated in comparison with cultures of urethral and cervical specimens. At the same time, the ability of leucocyte esterase (LE) in first-voided urine and the presence of leucocytes in urethral and cervical smears to identify C. trachomatis-infected individuals based on PCR and culture was determined. The prevalence of C. trachomatis infection was 10.9% in men and 7.7% in women. Sensitivity, specificity, positive predictive value and negative predictive value of Amplicor was 93.5%, 99.7%, 97.7% and 99.2% in males and 91.4%, 99.5%, 94.1% and 99.3% in females. All Chlamydia-infected men were identified by means of a combination of urethritis (4 leucocytes in the urethral smear) and/or a positive LE test in urine, although the specificity was only 42.2%. In women, the combination of urethritis and/or cervicitis and/or a positive LE test identified 85.7% of Chlamydia-infected patients with a specificity of 38.2%. It is concluded that a combination of urethral and/or cervical smears and LE testing of urine can be used as a screening test to select patients, especially males, for specific C. trachomatis testing.

The cost-effectiveness of screening men for Chlamydia trachomatis: a review of the literature

BACKGROUND

An important consideration in determining whether to implement or continue a program to screen men for chlamydia is its cost-effectiveness. A review of the literature on the cost-effectiveness of screening men for chlamydia could potentially provide guidance.

METHODS

An Ovid Medline search was conducted for articles published between 1990 and July 2007 using terms for cost, chlamydia, and male. This search returned 175 articles; 25 were retained after eliminating those not relevant to cost-effectiveness studies of male chlamydia screening. We added 4 articles that were in-press or are published in this issue, for a total of 29. These articles were examined for common themes and their results summarized.

RESULTS

The reviewed studies examined both proactive and opportunistic screening and included screening of risk groups and of the general population. Some older studies included enzyme immunoassays; more recent studies featured nucleic acid amplification assays. Six studies used dynamic transmission models. Fourteen studies analyzed male and female chlamydia screening interventions. Several contained sufficient data to examine the cost-effectiveness of male screening compared with female screening. Male screening was preferred to expanded female screening in 1 study. In other studies, combined male and female screening programs were cost-saving.

CONCLUSIONS

Studies comparing chlamydia screening in men with chlamydia screening in women may be the most useful for guidance to programs. The studies which compare the 2 generally have found that screening men from the general population is not preferred to screening women from the general population, although 1 study found that screening of men from risk groups can be cost-effective compared with screening women from the general population.

Acceptability of urine-based screening for Chlamydia trachomatis in asymptomatic young men: a systematic review

We performed a structured literature review of published studies from 2000-2007 that measured the acceptability and acceptance (uptake) of urine testing for C. trachomatis among asymptomatic men. Studies were categorized as three types: (a) non-STD clinic venues where men were approached in person and offered testing on site (urgent care clinics, freestanding clinics or health screening settings, corrections, community centers); (b) delivery of testing kits to men at their homes; and (c) qualitative measurement related to men's experience of screening. When offered in established nonhome-based settings (clinics, schools, corrections), acceptability and consequent uptake of testing by men is generally good (mid-60% range). However, acceptance rates even in these settings vary widely and are influenced by venue, provider, and a diversity of other factors. Acceptance of home-based testing invitations, including direct mailing of test kits, is considerably lower. Attitudinal characteristics of men who decline testing primarily include low self-perception of risk for asymptomatic infection and perceived inconvenience of providing test specimens. Given these findings, testing strategies targeting asymptomatic men in established community and clinic settings are most likely to yield relatively high acceptance rates. However, barriers to both implementation and uptake remain, even when such testing is free. Interventions to enhance uptake of testing in asymptomatic men should be developed and selected with underlying C. trachomatis population prevalence in mind.

Should asymptomatic men be included in chlamydia screening programs? Cost-effectiveness of chlamydia screening among male and female entrants to a national job training program

OBJECTIVE

To compare the cost-effectiveness of various chlamydia screening strategies within a population of male and female youth entering a national job training program.

STUDY DESIGN

Cost-effectiveness analysis of various chlamydia screening strategies among a cohort of 4000 female and male New England job training students. Strategies for women include (a) no screening, (b) universal endocervical DNA probe screening, (c) universal urine based NAAT screening, and (d) universal endocervical NAAT screening. Strategies for men include (a) no screening, (b) selective urine NAAT screening of leukocyte esterase (LE)-positive urines, and (c) universal urine-based NAAT screening.

RESULTS

Universal endocervical NAAT screening of women and universal urine NAAT screening of men were the most effective and cost-effective strategies individually and in combination. Endocervical NAAT screening of women prevented 23 more cases of PID and saved $27,000 more than endocervical DNA probe screening. Likewise, universal urine NAAT screening of men prevented 21 more cases of PID in their female partners and saved $16,000 more than selective urine NAAT screening of LE positive men.

CONCLUSIONS

Use of a sensitive NAAT to screen both men and women for chlamydia upon entry to a National Job Training Program is cost-effective, cost-saving, and provides a public health opportunity to substantially reduce chlamydia infections among youth at risk for sexually transmitted diseases.

One to one interventions to reduce sexually transmitted infections and under the age of 18 conceptions: a systematic review of the economic evaluations

OBJECTIVE

To systematically review and critically appraise the economic evaluations of one to one interventions to reduce sexually transmitted infections (STIs) and teenage conceptions.

DESIGN

Systematic review.

DATA SOURCES

Search of four electronic bibliographic databases from 1990 to January 2006. Search keywords included teenage, pregnancy, adolescent, unplanned, unwanted, cost benefit, cost utility, economic evaluation, cost effectiveness and all terms for STIs, including specific diseases.

REVIEW METHODS

We included studies that evaluated a broad range of one to one interventions to reduce STIs. Outcomes included major outcomes averted, life years and quality adjusted life years (QALY). All studies were assessed against quality criteria.

RESULTS

Of 3,190 identified papers, 55 were included. The majority of studies found one to one interventions to be either cost saving or cost effective, although one highlighted the need to target the population to receive post-exposure prophylaxis to reduce transmission of HIV. Most studies used a static approach that ignores the potential re-infection of treated patients.

CONCLUSION

One to one interventions have been shown to be cost saving or cost effective but there are some limitations in applying this evidence to the UK policy context. More UK research using dynamic modelling approaches and QALYs would provide improved evidence, enabling more robust policy recommendations to be made about which one to one interventions are cost effective in reducing STIs in the UK setting. The results of this review can be used by policy makers, health economists and researchers considering further research in this area.

Acceptability of urine-based screening for Chlamydia trachomatis to asymptomatic young men and their providers

OBJECTIVE

The objective of this study was to describe acceptability of urine chlamydia testing among asymptomatic men and providers' attitudes toward testing.

STUDY DESIGN

Asymptomatic men (no urethral discharge/dysuria) were offered free testing and characteristics of men who accepted were compared with those who declined. Acceptability logs tallied the proportion who accepted, and a standardized survey was administered to providers at study's end.

RESULTS

Median acceptance was 64% (range, 8-100%). Men accepting were younger and more likely to be in adolescent primary care or detention, to report higher numbers of recent partners, no prior sexually transmitted disease, time to last healthcare visit >1 year, and to have received an incentive. Provider-reported barriers to testing included difficulty in conveying importance of testing to asymptomatic men (65%) and time constraints (24%).

CONCLUSIONS

Asymptomatic men are likely to accept testing depending on venue and approach. However, barriers exist for men and providers, even when testing is free.

Opportunistic screening for Chlamydia trachomatis in men attending three different secondary healthcare settings

OBJECTIVES

To assess the feasibility and acceptability of opportunistic Chlamydia trachomatis (CT) screening of asymptomatic men attending three different secondary healthcare settings and to investigate CT positivity in these settings.

METHODS

Men attending fracture, fertility and family planning (FP) clinics were invited to be screened by first-void urine and complete a questionnaire which collected demographic, sexual and behavioural characteristics, and their opinion about the screening process.

RESULTS

1290 men were approached, with 80% participating. The number of men approached, number providing a satisfactory urine specimen and CT positivity rate (95% CI) were, respectively, n = 401, n = 206, 14.6% (10.4 to 20.1) for the FP clinic, n = 505, n = 328, 1.2% (0.5 to 3.2) for the fracture clinic and n = 384, n = 319, 0.3% (0.1 to 1.8) for the fertility clinic. The highest rates of CT infection were found in men attending the FP clinics, aged between 20-24 years. Most of the men from all three clinics felt that the setting (87.9%) and specimen (97.7%) were acceptable.

CONCLUSION

Opportunistic chlamydial screening of asymptomatic men in three secondary healthcare settings found high positivity rates, but low uptake rates in a FP setting compared with fertility and fracture clinics. Innovative and targeted intervention strategies are required to engage this high-risk group of men in screening.

Screening for Chlamydia trachomatis: a systematic review of the economic evaluations and modelling

OBJECTIVE

To review systematically and critically, evidence used to derive estimates of costs and cost effectiveness of chlamydia screening.

METHODS

Systematic review. A search of 11 electronic bibliographic databases from the earliest date available to August 2004 using keywords including chlamydia, pelvic inflammatory disease, economic evaluation, and cost. We included studies of chlamydia screening in males and/or females over 14 years, including studies of diagnostic tests, contact tracing, and treatment as part of a screening programme. Outcomes included cases of chlamydia identified and major outcomes averted. We assessed methodological quality and the modelling approach used.

RESULTS

Of 713 identified papers we included 57 formal economic evaluations and two cost studies. Most studies found chlamydia screening to be cost effective, partner notification to be an effective adjunct, and testing with nucleic acid amplification tests, and treatment with azithromycin to be cost effective. Methodological problems limited the validity of these findings: most studies used static models that are inappropriate for infectious diseases; restricted outcomes were used as a basis for policy recommendations; and high estimates of the probability of chlamydia associated complications might have overestimated cost effectiveness. Two high quality dynamic modelling studies found opportunistic screening to be cost effective but poor reporting or uncertainty about complication rates make interpretation difficult.

CONCLUSION

The inappropriate use of static models to study interventions to prevent a communicable disease means that uncertainty remains about whether chlamydia screening programmes are cost effective or not. The results of this review can be used by health service managers in the allocation of resources, and health economists and other researchers who are considering further research in this area.

The Direct Medical Cost of Epididymitis and Orchitis: Evidence From a Study of Insurance Claims

BACKGROUND

Epididymitis and orchitis (EO) are the primary sequelae of acute chlamydia and gonorrhea in men. Existing estimates of the cost per episode of epididymitis are over 10 years old or are based on limited data.

OBJECTIVE

The objective of this study was to estimate direct medical costs of EO from insurance claims data.

STUDY DESIGN

We used 1998 and 1999 insurance claims taken from a national database. We used International Classification of Diseases, 9th Revision codes to identify inpatient and outpatient claims for EO treatment. Prescription drug claims were identified with National Drug Codes. To capture episodes of EO that were most likely sequelae of sexually transmitted diseases, we categorized claims based on age at the time of the initial EO claim.

RESULTS

The total cost per episode was US dollars 368 for males <13 years of age, US dollars 242 for those > or =13 and <41 years of age, and US dollars 291 for those > or =41 years of age. The cost for both younger and older men was significantly different from men > or =13 and <41 years of age. Inpatient claims were relatively rare, occurring in < or =1.2% of total episodes.

CONCLUSION

The cost per episode we calculated was lower than previously published estimates and can be attributed to a lower rate of inpatient care than previously observed or estimated.

Cost-Effectiveness of Screening Strategies for Gonorrhea Among Females in Private Sector Care

OBJECTIVE

To identify the optimal screening algorithm for gonorrhea infection among females in private sector care, using cost-effectiveness analysis.

METHODS

We compared 6 strategies using decision analysis for urine nucleic acid amplification testing for gonorrhea testing in a theoretical cohort of 10,000 females aged 15-35 years: 1) screen women aged younger than 25 years; 2) screen women aged younger than 30 years; 3) screen women aged younger than 25 years who report any risk (pregnant, drug use, new sexual partner < 30 days); 4) screen women aged younger than 30 years who report any risk; 5) screen women aged younger than 25 years or those who report any risk; and 6) screen women aged younger than 30 years or those who report any risk. Infection prevalence and sensitivity and specificity were by direct observation from a retrospective cohort of females attending the Baltimore City Sexually Transmitted Disease Clinics between 1999 and 2002. The main outcome measures were untreated gonorrhea cases and their sequelae in women, transmission to a male partner, congenital outcomes, and cost to prevent a case.

RESULTS

Prevalence of gonorrhea was 3.0%. Not screening would result in 300 untreated cases. Not screening was cost-saving over all screening strategies. Strategy 6 resulted in the fewest cases of untreated infection (82), although Strategy 3 was the most cost-effective of the screening strategies. Univariate sensitivity analysis identified a threshold of 4.75% gonorrhea prevalence, more than which Strategy 3 became cost-saving over not screening.

CONCLUSION

Screening is recommended for females aged younger than 25 years with specific risks in populations with a gonorrhea prevalence of 4.75% or greater.

LEVEL OF EVIDENCE

II-2.

Chlamydial Infections Among Female Adolescents Screened in Juvenile Detention Centers in Washington State, 1998???2002

OBJECTIVE

The objective of this study was to assess trends in Chlamydia trachomatis positivity and associated risk factors among detained female adolescents.

GOAL

The goal of this study was to determine trends in prevalence of chlamydia among detained female adolescents.

STUDY DESIGN

We retrospectively reviewed risk factor data and chlamydia results collected by providers during 1998-2002 at four large juvenile detention centers in Washington State that routinely screen female adolescents for C. trachomatis.

RESULTS

Of 3,593 tests, a total of 493 (13.7%) were positive for chlamydia. High chlamydia positivity was sustained throughout the 5-year period (range, 12.5-15.0%) with no statistically significant trends in positivity. Independent risk factors for chlamydial infection included report of more than one sex partner in the previous 60 days (adjusted odds ratio [OR] = 1.56, 95% confidence interval [CI] = 1.19-2.04) and previous chlamydial infection within 12 months (adjusted OR = 1.87, 95% CI = 1.45-2.40).

CONCLUSIONS

Efforts are needed to promote chlamydia screening programs in juvenile detention centers because these sites have access to high-risk sexually active female adolescents.

Chlamydia trachomatis Testing Patterns and Prevalence of Genital Chlamydial Infection Among Young Men and Women in Central Norway 1990–2003: A Population-Based Registry Study

OBJECTIVE

The study objective was to investigate Chlamydia trachomatis (CT) testing patterns, prevalence, and incidence among men and women in Sør-Trøndelag county, central Norway, 1990-2003.

GOAL

The goal of this study was to obtain data for recommendations regarding CT screening.

STUDY DESIGN

Laboratory data on CT tests for persons 15 to 24 years old were retrieved and analyzed.

RESULTS

Four percent of men and 44% of women had been CT tested at least once by the age of 20. By the age of 25, 44% of men and 84% of women had been tested. Prevalence at first test was at its peak in 2000-2002 (men: 15-19 years 18%, 20-24 years 23%; women: 15-19 years 11%, 20-24 years 9%). Incidence estimates were higher for persons with a positive first test than for persons with a negative first test.

CONCLUSIONS

More men and more female teenagers need to be tested. Repeat testing is particularly important among people who have been diagnosed with CT.

Nucleic acid amplification tests for gonorrhea and chlamydia: practice and applications

Nucleic acid amplification tests (NAATs), which are highly sensitive and specific, have provided the ability to use alternative sam-ple types for the diagnosis of sexually transmitted infections (STIs). Self-collected genital specimens, such as urine or even vaginal swabs, can now be accurately used to diagnose gonorrhea or chlamydia infections. In many cases, use of these sample types can decrease the necessity for a clinician to perform a pelvic examination on women or to collect a urethral swab from men, thus extending the diagnostic capability for detecting these infections to nonclinic screening venues. As most chlamydia infections and many gonorrhea infections are asymptomatic, the use of NAATs for self-collected samples greatly increases the types and numbers of patients that can be screened outside of clinic settings. Self-sampling also allows clinicians to easily screen patients in the clinic for STIs who are not presenting for pelvic or urogenital examinations. The application of NAATs to self-collected specimens has the potential to augment public health programs designed to control the epidemic of STIs in the community.

Costs and effects of chlamydial screening: dynamic versus static modeling

OBJECTIVE

The objective of this study was to assess the impact of modeling type on the economic evaluation of screening programs for asymptomatic Chlamydia trachomatis infections.

STUDY

We compared a stochastic network simulation model (dynamic model) with a decision analysis model (static model) for estimating the cost-effectiveness of an opportunistic screening program. The influence of the model type on the required data, the computed results, and the sensitivity of model parameters were investigated.

RESULTS

When compared with static modeling, dynamic modeling yielded different cost-effectiveness ratios and identified other optimal screening strategies as it considers changes in the force of infection caused by screening. However, it is more complex, data- and time-demanding, and more sensitive to some parameters affecting the force of infection than static modeling.

CONCLUSIONS

Dynamic models should be applied for the economic evaluation of prevention measures that have the potential to lower the force of infection such as large-scale chlamydial screening programs.

Innovative Approaches to the Prevention and Control of Bacterial Sexually Transmitted Infections

Bacterial STI continues to be a major problem in developed nations. Research and evolving standards of public health practice are cause for optimism and concern. Innovations in case-finding and treatment, particularly the application of NAATs to test for chlamydial infection in nonclinical settings, are successes that merit more widespread application. EPT, selective STI screening in men, and rescreening are all promising, but are not yet in widespread use and may face significant operational barriers. To date, public health efforts to alter sexual behavior, at least through specific interventions, are more discouraging. Although some behavioral interventions have been effective, none has been widely instituted. Moreover, the likelihood that existing behavioral interventions will be widely applied seems remote. Future research efforts in this area will need to focus less on proof-of-concept efficacy trials and more on developing and testing sustainable, cost-effective interventions that focus on those at greatest risk and that can be scaled-up within the existing public health infrastructure.

Performance of urine leukocyte esterase in asymptomatic male youth: another look with nucleic acid amplification testing as the gold standard for Chlamydia detection

PURPOSE

To re-evaluate the sensitivity and specificity of leukocyte esterase (LE) for screening adolescent and young adult males for Chlamydia trachomatis using a nucleic acid amplification test (NAAT) as the gold standard.

METHODS

This study was conducted at two Massachusetts Department of Youth Services sites and one Job Corps site. Recently admitted asymptomatic sexually active male youth aged 14 to 25 years (mean 16.6 years) were recruited between January 2001 and July 2003 (N = 1008). Participants provided first part voided urine specimens for testing with LE and Chlamydia NAAT. The sensitivity, specificity, and positive and negative predictive value of urine LE for identification of Chlamydia infection were determined using NAAT as the gold standard.

RESULTS

Fifty-seven (5.7%) participants were infected with Chlamydia as defined by a positive NAAT. Defining trace + as the LE cut point resulted in sensitivity and specificity of 57.9% and 78.3%, respectively. Defining 1+ as the cut point resulted in sensitivity and specificity of 47.4% and 96.1%, respectively.

CONCLUSIONS

Urine leukocyte esterase is a moderately sensitive method to screen for Chlamydia. Nevertheless, a substantial proportion of infections are not detected with LE screening. When feasible, urine NAAT provides a much more sensitive and equally noninvasive method of detecting Chlamydia. However, if LE is used as an initial screen followed by NAAT confirmation of LE positive samples, we recommend using trace LE as the cut point for positive results.

Prevalence of Chlamydia trachomatis Infection Among Men Screened in 4 U.S. Cities

OBJECTIVE

The objective of this study was to measure the prevalence of Chlamydia trachomatis (CT) infection among men in clinical and nonclinical settings across the United States.

GOAL

The goal of this study was to obtain data to inform recommendations regarding male CT screening.

STUDY

The authors conducted a cross-sectional study of CT prevalence among adolescent and adult men in 4 U.S. cities (Baltimore, Denver, San Francisco, and Seattle). CT was detected using urine-based testing, and prevalence was calculated for first testing event.

RESULTS

Over 23,000 men were tested for CT over a 3 1/2-year period. The majority (96%) were asymptomatic. Overall, prevalence was 7% and varied significantly between cities (range: Seattle, 1%; Baltimore, 12%), by age (peak prevalence at age 20-24 years, 9%), and between venues where CT testing was offered.

CONCLUSIONS

At 7%, the prevalence of CT is moderately high among men opportunistically tested in nonclinical and clinical settings.

Adolescent sexually transmitted diseases: Recent developments

Adolescents and young adults continue to have the highest rates of sexually transmitted diseases. New chlamydia and gonorrhea diagnostic tests are being used in innovative ways to increase the number of infections that are detected. Nevertheless, challenges such as gonorrhea resistance and partner notification and treatment continue to hinder efforts to reduce the prevalence of these two bacterial infections. Although recent surveillance data suggest a decreasing trend of herpes simplex virus 2 (HSV-2) incidence among adolescents and young adults, the incidence of sexually transmitted human papillomavirus (HPV) in adolescent and young adult females remains high. Progress has been made toward the development of vaccines that may become available in the future to prevent infection with and sequelae from HSV-2 and HPV.

Cost-Effectiveness Analysis of Screening Adolescent Males for Chlamydia On Admission to Detention

BACKGROUND

Chlamydia trachomatis infections can lead to serious and costly sequelae. Because chlamydia is most often asymptomatic, many infected youth do not seek testing. Entry to a detention system provides an opportunity to screen and treat many at-risk youth. GOAL The goal of this study was to determine the cost-effectiveness of screening male youth for chlamydia on entry to detention.

STUDY DESIGN

Incremental cost-effectiveness of 3 chlamydia screening strategies was compared for a hypothetical cohort of 4000 male youth per year: 1) universal chlamydia screening using a urine-based nucleic acid amplification test (NAAT), 2) selective NAAT screening of urine leukocyte esterase (LE)-positive urines, and 3) no screening. The model incorporated programmatic costs of screening and treatment and medical cost savings from sequelae prevented in infected males and female partners. The analysis was conducted from the healthcare system perspective.

RESULTS

Chlamydia prevalence in the sampled population of 594 was 4.8%, and the average number of female sexual partners/infected male was 1.6. Universal NAAT screening was the most cost-effective strategy, preventing 37 more cases of pelvic inflammatory disease (PID) and 3 more cases of epididymitis than selective screening and saving an additional 24,000 dollars. The analysis was sensitive to NAAT cost, LE sensitivity, rate of PID development, PID sequelae cost, and number of female partners. Universal screening remained the most cost saving for prevalence as low as 2.8% or higher.

CONCLUSIONS

Universal chlamydia screening of adolescent males on entry to detention was the most cost-effective strategy. Savings are primarily the result of the prevention of PID in recent and future partners of index males. Screening detained male youth using a urine-based NAAT provides a public health opportunity to significantly reduce chlamydia infections in youth at risk for sexually transmitted diseases.