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

Cognitive social capital as a health-enabling factor for STI testing among young men in Stockholm, Sweden: A cross-sectional population-based study

Objective

To assess whether different forms of cognitive social capital increased the relative probability of testing for sexually transmitted infections (STIs) among young men living in Stockholm, Sweden.

Methods

A population-based cross-sectional study was conducted in 2017 with men aged 20-29 years living in Stockholm County, Sweden (n = 523). The main outcome was STI testing patterns (never tested, tested only within a12-monthperiod, tested only beyond a12-monthperiod, repeatedly tested). The main exposure were two forms of cognitive social capital: social support (having received help, having someone to share inner feelings with) and institutionalized trust (in school, healthcare, media). Data were analyzed using weighted multivariable multinomial logistic regression to obtain adjusted weighted relative probability ratio (aRPR).

Results

After adjusting for confounding factors, receiving help (aRPR: 5.2, 95% CI: 1.7-16.2) and having someone to share inner feelings with (aRPR: 3.1, 95% CI: 1.2-7.7) increased the relative probabilities of young men testing for STIs, but only for those testing beyond a 12-month period. Trust in media increased the relative probability of STI testing for those testing only within a 12-month period (aRPR: 2.6, 95% CI: 1.1-6.1) and for those testing repeatedly (aRPR: 3.6, 95% CI: 1.5-8.8).

Conclusion

Young men in Stockholm County exhibit distinct STI testing patterns. Social support and trust in media were factors that increased the probability of being tested for STIs, with this effect varying according to the young men's STI testing pattern. Further studies are required to explore how trust in media might promote STI testing in this population.

Denominators count: supplementing surveillance data for genital Chlamydia trachomatis infection with testing data, Norway, 2007 to 2013

As genital Chlamydia trachomatis (chlamydia) infection is often asymptomatic, surveillance of diagnosed cases is heavily influenced by the rate and distribution of testing. In 2007, we started supplementing case-based surveillance data from the Norwegian Surveillance System for Communicable Diseases (MSIS) with aggregated data on age group and sex of individuals tested. In this report, annual testing rates, diagnosis rates and proportion positive for chlamydia in Norway between 1990 and 2013 are presented. From 2007, rates are also stratified by age group and sex. The annual testing rate for chlamydia culminated in the early 1990s, with 8,035 tested per 100,000 population in 1991. It then declined to 5,312 per 100,000 in 2000 after which it remained relatively stable. Between 1990 and 2013 the annual rate of diagnosed cases increased 1.5 times from ca 300 to ca 450 per 100,000 population. The proportion of positive among the tested rose twofold from ca 4% in the 1990s to 8% in 2013. Data from 2007 to 2013 indicate that more women than men were tested (ratio: 2.56; 95% confidence interval (CI): 2.56-2.58) and diagnosed (1.54; 95% CI: 1.52-1.56). Among tested individuals above 14 years-old, the proportion positive was higher in men than women for all age groups. Too many tests are performed in women aged 30 years and older, where 49 of 50 tests are negative. Testing coverage is low (15%) among 15 to 24 year-old males. Information on sex and age-distribution among the tested helps to interpret surveillance data and provides indications on how to improve targeting of testing for chlamydia. Regular prevalence surveys may address remaining limitations of surveillance.

Predictors identifying those at increased risk for STDs: a theory-guided review of empirical literature and clinical guidelines

SummarySexually transmitted diseases (STDs) are leading causes of substantial morbidity worldwide. Identification of risk factors for estimating STD risk provides opportunities for optimising service delivery in clinical settings, including improving case finding accuracy and increasing cost-efficiency by limiting the testing of low-risk individuals. The current study was undertaken to synthesise the evidence supporting commonly cited chlamydia and gonorrhoea risk factors. The level of empirical support for the following predictors was strong/moderate: age, race/ethnicity, multiple lifetime sexual partners, sex with symptomatic partners and concurrent STD diagnosis. The following predictors had weak evidence: socio-economic status, transactional sex, drug/alcohol use, condom use and history of STD diagnosis. The most frequently listed predictors among nine clinical guidelines were younger age and multiple sexual partners; the least consistently listed predictor was inconsistent condom use. We found reasonably good concordance between risk factors consistently listed in the recommendations and predictors found to have strong empirical support in the literature. There is a need to continue building the evidence base to explicate the mechanisms and pathways of STD acquisition. We recommend periodic reviews of the level of support of predictors included in clinical guidelines to ensure that they are in accordance with empirical evidence.

Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: a randomized controlled trial

BACKGROUND

As most genital Chlamydia trachomatis infections are asymptomatic, many patients do not seek health care for testing. Infections remain undiagnosed and untreated. We studied whether screening with information and home sampling resulted in more young people getting tested, diagnosed and treated for chlamydia in the three months following the intervention compared to the current strategy of testing in the health care system.

METHOD

We conducted a population based randomized controlled trial among all persons aged 18-25 years in one Norwegian county (41 519 persons). 10 000 persons (intervention) received an invitation by mail with chlamydia information and a mail-back urine sampling kit. 31 519 persons received no intervention and continued with usual care (control). All samples from both groups were analysed in the same laboratory. Information on treatment was obtained from the Norwegian Prescription Database (NorPD). We estimated risk ratios and risk differences of being tested, diagnosed and treated in the intervention group compared to the control group.

RESULTS

In the intervention group 16.5% got tested and in the control group 3.4%, risk ratio 4.9 (95% CI 4.5-5.2). The intervention led to 2.6 (95% CI 2.0-3.4) times as many individuals being diagnosed and 2.5 (95% CI 1.9-3.4) times as many individuals receiving treatment for chlamydia compared to no intervention in the three months following the intervention.

CONCLUSION

In Norway, systematic screening with information and home sampling results in more young people being tested, diagnosed and treated for chlamydia in the three months following the intervention than the current strategy of testing in the health care system. However, the study has not established that the intervention will reduce the chlamydia prevalence or the risk of complications from chlamydia.

Population based study of genital Chlamydia trachomatis prevalence and associated factors in Norway: a cross sectional study

Background

The number of diagnosed cases of Chlamydia trachomatis infection has been increasing in the past years in Norway although the testing rate has been relatively stable. The aim of this study was to measure the prevalence of genital Chlamydia trachomatis in young men and women in one county in Norway and determine associated factors in order to better target preventive measures.

Methods

We mailed to a random sample of 10 000 persons aged 18–25 in Rogaland county a mail-back urine sample kit and a self-administered questionnaire with questions on socio-demographic details, health seeking behaviour and symptoms of and history of sexually transmitted diseases. Associations between current Clamydia trachomatis infection and the above mentioned factors were studied by multiple logistic regression.

Results

The response rate among women was 18.9% (930/4923) and 11.9% (605/5077) among men. The prevalence of Chlamydia trachomatis infection was 5.8% (95% CI 4.5-6.8) among women and 5.1% (95% CI 3.8-6.8) among men. For men a greater number of partners during the last year (p for trend < 0.001), and living in a municipality without a local youth clinic increased the odds of infection (OR 8.6, 95% CI 2.2-33.9). For women a greater number of partners during the last year (p < 0.001) and not having consulted a family doctor for STIs (OR 2.1 95% CI 1.1-4.2) were positively associated with infection while not having a previous Chlamydia trachomatis diagnosis decreased the odds of having this infection (OR 0.3, 95% CI 0.2-0.7).

Conclusion

Our results indicate the importance of having a visible youth clinic in each municipality. It also suggests targeting women who have had a previous Chlamydia trachomatis infection diagnosed before.

Sexually transmitted infections among Pakistani pregnant women and their husbands in Norway

Aim

To assess frequency and determine the factors associated with Chlamydia trachomatis, herpes simplex virus type 2, and hepatitis B seropositivity among Pakistani pregnant women and their husbands in Norway.

Methods

All together 112 couples of Pakistani origin living in Norway participated in our study. Blood samples were tested for immunoglobulin G (IgG) antibodies against C. trachomatis, herpes simplex virus type 2, and hepatitis B.

Results

Pakistani women had significantly lower age, education level, and years of residence in Norway compared to their male partners. Among the men, 12% had positive chlamydial IgG antibodies in contrast to 1% of the women. These couples were discordant, meaning that the 13 wives of positive men were not infected with C. trachomatis, and the husband of one positive woman was not infected either. Four percent of women and 2% of men were positive for herpes simplex type 2. Only one couple was concordantly positive for herpes simplex type 2, the remaining four couples were discordant. Twelve percent of women and 21% of men were, or had been, infected with hepatitis B.

Conclusion

Sexually transmitted infections did not seem to be prevalent in Pakistani immigrant couples in Norway. However, it was striking that most couples were discordant. Pakistani immigrants should be offered hepatitis B vaccine.

Comparing urine samples and cervical swabs for Chlamydia testing in a female population by means of Strand Displacement Assay (SDA)

Background

There has been an increasing number of diagnosed cases of Chlamydia trachomatis in many countries, in particular among young people. The present study was based on a growing request to examine urine as a supplementary or primary specimen in screening for Chlamydia trachomatis in women, with the Becton Dickinson ProbeTec (BDPT) Strand Displacement Assay (SDA). Urine samples may be particularly important in screening young people who are asymptomatic.

Methods

A total of 603 women aged 15 and older were enrolled from the Sexually Transmitted Infection (STI) clinic at Haukeland University Hospital, Norway, in 2007. Only 31 women were older than 35 years. Cervical swabs and urine samples were tested with BDPT for all participants. In cases of discrepant test results from a given patient, both samples were retested by Cobas TaqManCT and a Polymerase Chain Reaction (PCR)-method (in-house). Prevalence of C. trachomatis, sensitivity, and specificity were estimated by latent class analysis using all test results available. Bootstrap BC confidence intervals (10 000 computations) were estimated for sensitivity and specificity, and their differences in cervix vs. urine tests.

Results

A total of 1809 specimens were collected from 603 patients. 80 women (13.4%) were positive for C. trachomatis. Among these, BDPT identified 72 and 73 as positive in cervix and urine samples, respectively. Of the 523 C. trachomatis negative women, BDPT identified 519 as negative based on cervical swabs, and 514 based on urine samples. Sensitivity for cervical swabs and urine samples with the BDPT were 89.0% (95% CI 78.8, 98.6) and 90.2% (95% CI 78.1, 95.5), respectively. The corresponding values for specificity were 99.2% (95% CI 98.3, 100) and 98.3% (95% CI 96.4, 100).

Conclusions

This study indicates that urine specimens are adequate for screening high-risk groups for C. trachomatis by the SDA method (BDPT). Such an approach may facilitate early detection and treatment of the target groups for screening, and be cost-effective for patients and the health services.

Repeat infection with Chlamydia and gonorrhea among females: a systematic review of the literature

Determining the magnitude of chlamydia and gonorrhea reinfection is critical to inform evidence-based clinical practice guidelines related to retesting after treatment. PubMed was used to identify peer-reviewed English language studies published in the past 30 years that estimated reinfection rates among females treated for chlamydia or gonorrhea. Included in this analysis were original studies conducted in the United States and other industrialized countries that reported data on chlamydia or gonorrhea reinfection in females. Studies were stratified into 3 tiers based on study design. Reinfection rates were examined in relation to the organism, study design, length of follow-up, and population characteristics. Of the 47 studies included, 16 were active cohort (Tier 1), 15 passive cohort (Tier 2), and 16 disease registry (Tier 3) studies. The overall median proportion of females reinfected with chlamydia was 13.9% (n = 38 studies). Modeled chlamydia reinfection within 12 months demonstrated peak rates of 19% to 20% at 8 to 10 months. The overall median proportion of females reinfected with gonorrhea was 11.7% (n = 17 studies). Younger age was associated with higher rates of both chlamydia and gonorrhea reinfection. High rates of reinfection with chlamydia and gonorrhea among females, along with practical considerations, warrant retesting 3 to 6 months after treatment of the initial infection. Further research should investigate effective interventions to reduce reinfection and to increase retesting.

Incidence of pelvic inflammatory disease in a large cohort of women tested for Chlamydia trachomatis: a historical follow-up study

Background

Chlamydia trachomatis is a highly prevalent sexually transmitted disease. Testing rates among young Norwegian women are high. Young women diagnosed with C. trachomatis are often worried about future complications.

Methods

Our cohort consisted of 24,947 women born 1970–1984 who were tested for C. trachomatis infection during 1990–2005. We linked C. trachomatis laboratory data to data on hospitalizations for pelvic inflammatory disease during 1990–2005. Cox regression analysis with time-dependent covariates adjusted for age at first test was used to assess the association between C. trachomatis history and pelvic inflammatory disease.

Results

Follow-up until the end of 2005 included 201,387 woman-years. The incidence rate of hospitalization for pelvic inflammatory disease was higher among women with prior C. trachomatis infection than among women with negative tests only (48 events during 32,057 person-years and 143 events during 169,192 person-years, corresponding to 0.15 and 0.08 per 100 person-years, respectively). The corresponding hazard ratio adjusted for age at first test was 1.69 (95% CI, 1.21–2.36).

Conclusion

Our data show a link between a diagnosis of C. trachomatis infection and subsequent pelvic inflammatory disease. However, pelvic inflammatory disease was a rare event irrespective of C. trachomatis status. These, together with other recent findings, can be used to reassure women worried about their future reproductive health following a diagnosis of C. trachomatis.

Incidence and risk factors for genital Chlamydia trachomatis infection: a 4-year prospective cohort study

BACKGROUND

Few long-term studies reporting incidence and behavioral data for Chlamydia trachomatis (CT) infection in the general population have been published. Such studies are important to understand risk factors associated with infection and to develop screening recommendations.

METHODS

A fixed prospective 4-year cohort study of 898 sexually active Norwegian women, aged 16 to 23 years at study start, was conducted to assess incidence, repeat infection, and risk factors associated with genital CT infection. Participants were interviewed at study start and at 6-month intervals thereafter for behavioral characteristics. The women were tested for CT infection at 12-month intervals beginning at study start. Risk factors were assessed using Fisher exact test and conditional logistic regression. Person-time was estimated in survival analyses and incidence of CT infection was reported as events per 100 woman-years.

RESULTS

Median duration of observation was 48.0 months (range 10-74) whereas 4.4 specimens were collected per woman (range 2-5). Of the 836 women eligible for the analysis, 19 (2.2%) had a prevalent infection at baseline. The 4-year cumulative incidence of CT infection was 7.7 (95% CI: 6.7-8.7) with annual incidences ranging from 1.2 to 2.9 per 100 woman-years. The 2-year cumulative incidence of repeat CT infection was 11.2 (95% CI: 9.3-13.1) per 100 woman-years. In multivariate analyses, factors associated with incident CT infection were young age (< or =24 years) and number of new partners over the last 12 months prior being tested.

CONCLUSION

The annual incidences observed for women 24 years or younger with 1 or more new partners over the last 12 months support recommendations for annual testing for CT in this age group in Norway.

Home sampling and pooling of vaginal samples are effective tools for genetic screening of Chlamydia trachomatis among high school female students in Lithuania

The aims were 1) to estimate the prevalence of C. trachomatis infection among sexually active female students in Kaunas, Lithuania; 2) to investigate the usefulness of personal invitation, self-sampling, and pooling of samples for screening; and 3) to evaluate the costs of the approaches used. A cross-sectional study inviting 795 female students (18-31 y of age) from 7 high schools and 1 college in Kaunas was performed. The response rate was 67% (533/795). Self-obtained vaginal samples were analysed, individually and pooled (n = 3), using Digene Hybrid Capture II CT/NG Test. The overall prevalence of C. trachomatis infection was 5.6%. Among the sexually active female students 20-24 y of age (n = 424), the prevalence was 7.1%; however, the prevalence varied from 0% to 14.2% at the different schools. For estimation of the population prevalence based solely on identification of C. trachomatis positive pools, the pooling strategy reduced the costs by 85%. For estimation of population prevalence and for diagnosis of each individual sample, pooling reduced the costs by 70%. Targeted screening, using pooling to reduce the expenses, mainly of 3rd and 4th y Lithuanian female students could be recommended. By extended personal contact and internet-based communication, increased participation rates may be attained.

Chlamydia trachomatis and ectopic pregnancy: recent epidemiological findings

PURPOSE OF REVIEW

Genital Chlamydia trachomatis is common among young, sexually active people. Infections are most often asymptomatic but have potential long-term consequences for female reproductive health. The link between C. trachomatis and ectopic pregnancy is mainly based on early seroepidemiological case-control studies including women who had their sexual debut at a time at which testing was sparse. The purpose of the present review is to summarize recent findings in C. trachomatis and ectopic pregnancy epidemiology.

RECENT FINDINGS

The number of prevalence studies is high but results are specific for the setting in which the study was conducted. High prevalences are often found among adolescents and young adults. At the same time, decreased ectopic pregnancy rates are reported. Registry studies from the Scandinavian countries have shown low ectopic pregnancy rates among women tested for C. trachomatis and diverging results considering whether women are at increased risk following infection.

SUMMARY

Recent studies on C. trachomatis infection and ectopic pregnancy are few. The recent Scandinavian registry studies include women with diagnosed, and hence presumably treated, infections. The observation of low complication rates in these studies cannot be used as an argument against the importance of screening for C. trachomatis infections.

Norwegian men diagnosed with genital Chlamydia trachomatis infection notified two-thirds of their sexual partners

Chlamydia trachomatis (CT) is a widespread, sexually transmitted disease with potential long-term effects on female reproductive health. The objective of this study was to investigate compliance to treatment, partner notification, and attendance for test-of-cure among Norwegian men diagnosed with CT. We conducted a longitudinal case-series study among 81 CT positive men identified in a cross-sectional study (n = 1032, April-December 2005). Participants were interviewed on partner notification intentions at the treatment visit and on partner notification actions at the test-of-cure visit. Of the 81 patients, 8 (10%) did not meet for treatment, 2 were treated elsewhere, and 6 were treated but not interviewed. At the treatment visit, the 65 interviewed men reported that they intended to notify 100 out of 165 partners (61%). 40 of 71 treated patients attended for test-of-cure (56%). Four men (10%) needed repeated treatment. The 35 men interviewed at test-of-cure visit reported that 63 out of 95 partners (68%) had been notified. In conclusion, men diagnosed with CT infection are relatively open on notifying sexual partners but have low compliance to meeting for test-of-cure.

Births and Ectopic Pregnancies in a Large Cohort of Women Tested for Chlamydia trachomatis

BACKGROUND

Recent studies show divergent results concerning the risk of ectopic pregnancy following Chlamydia trachomatis (CT) infection.

GOAL

Our goal was to investigate future reproductive health outcomes (births and ectopic pregnancies) among women tested for CT.

METHODS

Our cohort consisted of 20,762 women born during 1970-1984 who were tested for CT during 1990-2003. We linked CT data to data on ectopic pregnancies and births during 1990-2004. Cox regression with time-dependent covariates was used to assess the association between CT history and births/ectopic pregnancies adjusted for age at first test. Analyses with ectopic pregnancy as outcome were also adjusted for parity.

RESULTS

We observed 9.6 births per 100 person-years of observation among women with negative tests only and 10.2 per 100 person-years among women with at least 1 positive test (hazard ratio adjusted for age at first test, 1.07; 95% CI, 1.01-1.12). Ectopic pregnancy incidence rates were higher for women with positive test(s) compared with women with negative test only (0.24 vs. 0.13 per 100 person-years; hazard ratio adjusted for age at first test and parity, 1.82; 95% CI, 1.27-2.60). Among women with at least 1 registered pregnancy, the adjusted hazard ratio was 2.03; 95% CI, 1.28-3.22).

CONCLUSION

Although women diagnosed with CT were at higher risk for ectopic pregnancy than women with negative test results only, our study suggest that their fertility prospects were better than they would have been had CT screening not been implemented in this population. Opportunistic CT screening is an appropriate method for maintaining female reproductive health.

Chlamydia trachomatis among young Norwegian men: sexual behavior and genitourinary symptoms

OBJECTIVE

The study objective was to assess Chlamydia trachomatis (CT) prevalence, risk factors, and genitourinary symptoms among young men.

METHODS

Sexually active men 18 to 30 years old were recruited during April through October 2005 at the student health services and through field work at university campuses in 2 Norwegian cities. A total of 1,032 participants completed a questionnaire on sexual behavior and provided first-void urine for CT testing.

RESULTS

The overall CT prevalence was 7.8% (81 of 1,032). In multivariable analysis, >or=5 lifetime sexual partners (adjusted odds ratio [aOR]: 2.7, 95% confidence interval [CI]: 1.4-5.2), a burning sensation on urination (aOR: 5.7, 95% CI: 3.1-10.5), and penile discharge (aOR: 2.6, 95% CI: 1.1-6.3) were significant risk factors for a positive CT test, whereas condom use (last intercourse) was preventive (aOR: 0.4, 95% CI: 0.2-0.8).

CONCLUSIONS

A CT prevalence of 7.8% was found among male students. Promotion of increased testing among men is important to prevent CT transmission.

Chlamydia trachomatis infections increase the risk for ectopic pregnancy: a population-based, nested case-control study

BACKGROUND

Chlamydia trachomatis (CT) as a risk factor for ectopic pregnancy (EP) has mainly been established through seroepidemiologic cross-sectional studies.

GOAL

The goal of this study was to obtain EP risk estimates for women diagnosed with CT using women with negative tests as the reference group.

METHODS

We linked prospectively collected CT laboratory data (1990-2003) to EP hospital data (discharge and outpatient registries) in a nested case-control study. Six hundred sixteen women with CT test(s) before first EP were eligible as cases. Three controls were matched to each case for year of birth, age at first test, and number of prior tests.

RESULTS

Previous CT infection was associated with elevated EP risk (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.0-2.0). In stratified analysis, the association was only significant for the youngest women (born 1970-1984) who had a nearly complete CT testing history (OR, 2.1; 95% CI, 1.3-3.2).

CONCLUSION

A history of diagnosed CT infection is associated with a 2-fold increased EP risk.

Urine gonococcal/Chlamydia testing in adolescents

PURPOSE OF REVIEW

This review will highlight the recent literature findings regarding urine-based Chlamydia and gonorrhea testing in adolescents.

RECENT FINDINGS

Rates of Chlamydia trachomatis are increasing, likely due to increased detection efficiency, but have not yet begun to decrease. Neisseria gonorrhoeae is at an all-time low. Urine-based testing for sexually transmitted infections is readily available and convenient but underutilized. Interesting approaches to a more universal screening program, including self-collected, mail-in urine samples, have been shown to be effective.

SUMMARY

In spite of recommendations urging universal screening for C. trachomatis and N. gonorrhoeae and the availability of highly accurate and convenient tests, screening rates for adolescents and young adults remain below the universal recommendations. Strategies to improve screening rates should take advantage of urine-based screening methodologies for sexually transmitted infections because of their cost-effectiveness as well as the convenience for patient and provider.