Repeat genitalChlamydia trachomatistesting rates in young adults in England, 2010

Patterns of sexual behaviour associated with repeated chlamydia testing and infection in men and women: a latent class analysis

BACKGROUND

Adolescents and young adults are at higher risk of acquiring Chlamydia trachomatis infection (chlamydia), so testing is promoted in these populations. Studies have shown that re-testing for chlamydia is common amongst them. We investigated how sexual risk behaviour profiles are associated with repeated testing for chlamydia.

METHODS

We used baseline data from a cohort of 2814 individuals recruited at an urban STI -clinic. We applied latent class (LC) analysis using 9 manifest variables on sexual behaviour and substance use self-reported by the study participants. We fitted ordered logistic regression to investigate the association of LC membership with the outcomes repeated testing during the past 12 months and lifetime repeated testing for chlamydia. Models were fit separately for men and women.

RESULTS

We identified four LCs for men and three LCs for women with increasing gradient of risky sexual behaviour. The two classes with the highest risk among men were associated with lifetime repeated testing for chlamydia: adjOR = 2.26 (95%CI: 1.50-3.40) and adjOR = 3.03 (95%CI: 1.93-4.74) as compared with the class with lowest risk. In women, the class with the highest risk was associated with increased odds of repeated lifetime testing (adjOR =1.85 (95%CI: 1.24-2.76)) and repeated testing during past 12 months (adjOR = 1.72 (95%CI: 1.16-2.54)). An association with chlamydia positive test at the time of the study and during the participant's lifetime was only found in the male highest risk classes.

CONCLUSION

Prevention messages with regard to testing for chlamydia after unprotected sexual contact with new/casual partners seem to reach individuals in highest risk behaviour classes who are more likely to test repeatedly. Further prevention efforts should involve potentially more tailored sex-specific interventions taking into consideration risk behaviour patterns.

Assessing local chlamydia screening performance by combining survey and administrative data to account for differences in local population characteristics

Reducing health inequalities requires improved understanding of the causes of variation. Local-level variation reflects differences in local population characteristics and health system performance. Identifying low- and high-performing localities allows investigation into these differences. We used Multilevel Regression with Post-stratification (MRP) to synthesise data from multiple sources, using chlamydia testing as our example. We used national probability survey data to identify individual-level characteristics associated with chlamydia testing and combined this with local-level census data to calculate expected levels of testing in each local authority (LA) in England, allowing us to identify LAs where observed chlamydia testing rates were lower or higher than expected, given population characteristics. Taking account of multiple covariates, including age, sex, ethnicity, student and cohabiting status, 5.4% and 3.5% of LAs had testing rates higher than expected for 95% and 99% posterior credible intervals, respectively; 60.9% and 50.8% had rates lower than expected. Residual differences between observed and MRP expected values were smallest for LAs with large proportions of non-white ethnic populations. London boroughs that were markedly different from expected MRP values (≥90% posterior exceedance probability) had actively targeted risk groups. This type of synthesis allows more refined inferences to be made at small-area levels than previously feasible.

Temporal Patterns in Chlamydia Repeat Testing in Massachusetts

INTRODUCTION

National guidelines recommend test-of-cure for pregnant women and test-of-reinfection for all patients with chlamydia infections in order to interrupt transmission and prevent adverse sequelae for patients, partners, and newborns. Little is known about retesting and positivity rates, and whether they are changing over time, particularly in private sector practices.

METHODS

Electronic health record data on patients with chlamydia tests were extracted from three independent clinical practice groups serving ≅20% of the Massachusetts population. Records were extracted using the Electronic medical record Support for Public Health platform (esphealth.org). These data were analyzed for temporal trends in annual repeat testing rates by using generalized estimating equations after index positive chlamydia tests between 2010 and 2015 and for differences in intervals to first repeat tests among pregnant females, non-pregnant females, and males. Data extraction and analysis were performed during calendar years 2017 and 2018.

RESULTS

An index positive C. trachomatis result was identified for 972 pregnant female cases, 10,309 non-pregnant female cases, and 4,973 male cases. Test-of-cure 3-5 weeks after an index positive test occurred in 37% of pregnant females. Test-of-reinfection 8-16 weeks after an index positive test occurred in 39% of pregnant females, 18% of non-pregnant females, and 9% of males. There were no significant increases in test-of-cure or test-of-reinfection rates from 2010 to 2015. Among cases with repeat tests, 16% of pregnant females, 15% of non-pregnant females, and 16% of males had positive results.

CONCLUSIONS

Chlamydia test-of-cure and test-of-reinfection rates are low, with no evidence of improvement over time. There are substantial opportunities to improve adherence to chlamydia repeat testing recommendations.

[Sexually transmitted infections in Germany : The current epidemiological situation]

Sexually transmitted infections (STIs) can impair sexual health. Surveillance and study data were used to provide an overview over STIs in Germany. We estimated 3900 new HIV diagnoses in 2015. Of newly diagnosed infections, 57% were attributed to men who have sex with men (MSM). It was further estimated that there were 3200 new HIV infections and 84,700 people living with HIV in 2015. A total of 6834 syphilis infections were recorded in 2015, which corresponds to an increase of 149% since 2009. The incidence in men was 16-times higher than in women. Of syphilis infections, 85% could be attributed to MSM. Antimicrobial resistance of gonococci against the broad-spectrum antibiotic cefixime decreased between 2014 and 2016 after a change of therapy guidelines and remained stable on a low level regarding the antibiotic ceftriaxone. After an increase of resistance against the antibiotic azithromycin to 11.3% in 2015, we observed a decreasing trend in 2016. Between 2013 and 2015, 2,355,336 chlamydia tests were reported through the chlamydia sentinel network. Of these, 92.5% of samples were from women. Uptake for screening for women <25 years was 11.3% in 2015, with 5.0% positive chlamydia tests. In a cross-sectional study among women aged 20-25 years, a prevalence of human papilloma virus (HPV) of 38.1% was observed. A total of 30.5% of 15-year-old women were vaccinated against HPV in 2014. Data suggest that STIs represent a high burden of disease. Knowledge of STI prevention should be improved by targeted education campaigns. Extending existing offers for counselling and testing through cooperation between different health sectors would improve early diagnosis and treatment of STIs.

What Is the Optimal Time to Retest Patients With a Urogenital Chlamydia Infection? A Randomized Controlled Trial

Urogenital chlamydia patients returned for a retest either at 8, 16, or 26 weeks posttreatment. The retest uptake was highest in the 8-week group; positivity rates were similar between groups.

Background

Chlamydia trachomatis is a common, often recurring sexually transmitted infection, with serious adverse outcomes in women. Current guidelines recommend retesting after a chlamydia infection, but the optimum timing is unknown. We assessed the optimal retest interval after urogenital chlamydia treatment.

Methods

A randomized controlled trial among urogenital chlamydia nucleic acid amplification test positive heterosexual clients of the Amsterdam sexually transmitted infection clinic. After treatment, patients were randomly assigned for retesting 8, 16, or 26 weeks later. Patients could choose to do this at home (and send a self-collected sample by mail) or at the clinic. Retest uptake and chlamydia positivity at follow-up were calculated.

Results

Between May 2012 and March 2013, 2253 patients were included (45% men; median age, 23 years; interquartile range, 21–26). The overall uptake proportion within 35 weeks after the initial visit was significantly higher in the 8-week group (77%) compared with the 16- and 26-week groups (67% and 64%, respectively, P < 0.001), and the positivity proportions among those retested were comparable (P = 0.169). The proportion of people with a diagnosed recurrent chlamydia infection among all randomized was similar between the groups (n = 69 [8.6%], n = 52 [7.4%], and n = 69 [9.3%]; P = 0.4).

Conclusions

Patients with a recent urogenital chlamydia are at high risk of recurrence of chlamydia and retesting them is an effective way of detecting chlamydia cases. We recommend inviting patients for a re-test 8 weeks after the initial diagnosis and treatment.

High chlamydia and gonorrhoea repeat positivity in remote Aboriginal communities 2009-2011: longitudinal analysis of testing for re-infection at 3 months suggests the need for more frequent screening

Background Extremely high rates of diagnosis of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been recorded in remote communities across northern and central Australia. Re-testing at 3 months, after treatment administered, of CT or NG is recommended to detect repeat infections and prevent morbidity and ongoing transmission.

METHODS

Baseline CT and NG laboratory data (2009-2010) from 65 remote health services participating in a cluster randomised trial was used to calculate the proportion of individuals re-tested after an initial CT or NG diagnosis at <2 months (not recommended), 2-4 months (recommended) and 5-12 months and the proportion with repeat positivity on re-test. To assess if there were difference in re-testing and repeat positivity by age group and sex, t-tests were used.

RESULTS

There was a total of 2054 people diagnosed with CT and/or NG in the study period; 14.9% were re-tested at 2-4 months, 26.9% at 5-12 months, a total of 41.8% overall. Re-testing was higher in females than in males in both the 2-4-month (16.9% v. 11.5%, P<0.01) and 5-12-month (28.9% v. 23.5%, P=0.01) periods. Women aged 25-29 years had a significantly higher level of re-testing 5-12 months post-diagnosis than females aged 16-19 years (39.8% v. 25.4%, P<0.01). There was a total of 858 people re-tested at 2-12 months and repeat positivity was 26.7%. There was higher repeat NG positivity than repeat CT positivity (28.8% v. 18.1%, P<0.01).

CONCLUSIONS

Just under half the individuals diagnosed with CT or NG were re-tested at 2-12 months post-diagnosis; however, only 15% were re-tested in the recommended time period of 2-4 months. The higher NG repeat positivity compared with CT is important, as repeat NG infections have been associated with higher risk of pelvic inflammatory disease-related hospitalisation. Findings have implications for clinical practice in remote community settings and will inform ongoing sexual health quality improvement programs in remote community clinics.

Repeat Chlamydia trachomatis testing among heterosexual STI outpatient clinic visitors in the Netherlands: a longitudinal study

BACKGROUND

Chlamydia infections are common in both men and women, are often asymptomatic and can cause serious complications. Repeat testing in high-risk groups is therefore indicated. In the Netherlands, guidelines on repeat chlamydia testing differ between testing facilities, and knowledge on repeat testing behaviour is limited. Here, we analyse the current repeat testing behaviour of heterosexual STI clinic visitors, and aim to identify groups for which repeat testing advice could be advantageous.

METHODS

Longitudinal surveillance data from all Dutch STI outpatient clinics were used, which included all STI clinic consultations carried out among heterosexual men and women between June 2014 and December 2015. Repeat testing was defined as returning to the same STI clinic between 35 days and 12 months after initial consultation. We calculated chlamydia positivity at repeat test stratified by initial test result and time between consultations. Logistic regression analyses were used to identify predictors of repeat testing, and predictors of having a chlamydia positive repeat test.

RESULTS

In total, 140,486 consultations in 75,487 women and 46,286 men were available for analyses. Overall, 15.4% of women and 11.1% of men returned to the STI clinic within the study period. Highest chlamydia positivity at repeat test was seen 3-5 months after initial positive test. Among both women and men, repeat testing was associated with non-Western ethnicity, having had more than two sex partners in the past 6 months, reporting STI symptoms, having a history of STI, and having a chlamydia positive initial test. Among repeat testers, chlamydia positive repeat test was most strongly associated with younger age, followed by a chlamydia positive initial test.

CONCLUSIONS

Repeat testing most often resulted in a positive test result among young heterosexuals (<25) and heterosexuals of any age with a chlamydia infection at the initial consultation. Further efforts are needed to determine optimal repeat testing strategies.

Patterns of chlamydia testing in different settings and implications for wider STI diagnosis and care: a probability sample survey of the British population

Background

Following widespread rollout of chlamydia testing to non-specialist and community settings in the UK, many individuals receive a chlamydia test without being offered comprehensive STI and HIV testing. We assess sexual behaviour among testers in different settings with a view to understanding their need for other STI diagnostic services.

Methods

A probability sample survey of the British population undertaken 2010–2012 (the third National Survey of Sexual Attitudes and Lifestyles). We analysed weighted data on chlamydia testing (past year), including location of most recent test, and diagnoses (past 5 years) from individuals aged 16–44 years reporting at least one sexual partner in the past year (4992 women, 3406 men).

Results

Of the 26.8% (95% CI 25.4% to 28.2%) of women and 16.7% (15.5% to 18.1%) of men reporting a chlamydia test in the past year, 28.4% of women and 41.2% of men had tested in genitourinary medicine (GUM), 41.1% and 20.7% of women and men respectively tested in general practice (GP) and the remainder tested in other non-GUM settings. Women tested outside GUM were more likely to be older, in a relationship and to live in rural areas. Individuals tested outside GUM reported fewer risk behaviours; nevertheless, 11.0% (8.6% to 14.1%) of women and 6.8% (3.9% to 11.6%) of men tested in GP and 13.2% (10.2% to 16.8%) and 9.6% (6.5% to 13.8%) of women and men tested in other non-GUM settings reported ‘unsafe sex’, defined as two or more partners and no condom use with any partner in the past year. Individuals treated for chlamydia outside GUM in the past 5 years were less likely to report an HIV test in that time frame (women: 54.5% (42.7% to 65.7%) vs 74.1% (65.9% to 80.9%) in GUM; men: 23.9% (12.7% to 40.5%) vs 65.8% (56.2% to 74.3%)).

Conclusions

Most chlamydia testing occurred in non-GUM settings, among populations reporting fewer risk behaviours. However, there is a need to provide pathways to comprehensive STI care to the sizeable minority at higher risk.

Chlamydia trachomatis re-infection in Spain: A STI clinic-based cohort study

BACKGROUND

Chlamydia trachomatis (C. trachomatis) is the most frequently reported sexually transmitted infection (STI) in developed countries, but there is a lack data on its incidence and population dynamics in Spain. The objectives of this study were to estimate the incidence of C. trachomatis in patients seeking medical attention in an STI clinic with a defined population catchment area, to identify factors associated with this infection, and to explore differences between factors associated with new infections and re-infections.

METHODS

A retrospective study was conducted on a cohort of patients from a STI clinic who underwent chlamydia testing at least twice between 2007 and 2015.

RESULTS

Of the 2633 patients who met study selection criteria, 795 (30.2%) tested positive for C. trachomatis at baseline (baseline Chlamydia). The overall incidence was 7.97/100 person-years (95% CI: 7.2-8.8): 5.9/100 person-years (95% CI: 5.2-6.7) among patients testing negative for C. trachomatis at baseline, and 18.3 person-years (95% CI: 15.6-21.5) among those testing positive at baseline. In multivariate analysis, the factors independently associated with overall incidence were a history of infection with C. trachomatis in the previous 6 months (hazard ratio=3.6; 95% CI: 2.3-5.4), younger age (HR <20 vs ≥35 years=5.5; 95% CI: 3.2-9.5), male sex, 2 or more sexual partners in the previous month and year, and inconsistent condom use.

CONCLUSIONS

Guidelines should be established for C. trachomatis in Spain, including recommendations on the need for follow-up and re-testing, independently of age. Though data concerning the optimal timing of re-testing are inconclusive, our findings support the establishment of a 3-6 month interval.

Chlamydia trachomatis among Youth - Testing Behaviour and Incidence of Repeat Testing in Stockholm County, Sweden 2010-2012

Background

Widespread testing and screening for genital Chlamydia trachomatis is often advocated as an important method to halt the epidemic. Sweden has long tradition of opportunistic screening services. Nevertheless infections rates have continued to rise over the past two decades, despite increased access to testing and treatment services.

Methods

In this retrospective cohort study we describe the testing behavior for genital Chlamydia trachomatis among youth in Stockholm County, with a focus on repeated testing. Specifically we (a) study positivity rates among single and repeat testers, we (b) estimate the incidence of repeat testing and the rates of infection in repeat testing episodes, and we (c) estimate time to repeat testing and factors associated with repeat testing. All youth (aged ≥12 and <26) that tested for Chlamydia trachomatis in one of 33 Youth Health Clinics in Stockholm County between 1 January 2010 and 31 December 2012 were included in the study.

Results

The cohort comprised a total of 65,951 individuals who did 119,699 tests during the study period. 42% of youth were repeat testers, the incidence of repeat testing was 35.0/100 person years. The overall baseline prevalence was 7.9%. Positivity rates of baseline tests among repeat testers were nearly twice as high among single testers of either sex. These were 17.1% and 9.8% among male repeat and single testers respectively. The corresponding rates for women were 9.4% and 4.3%. Positivity rates among repeat tests did not decline compared to the overall baseline positivity. Baseline test result and sex significantly influenced the occurrence of repeat testing.

Conclusion

Among repeat testers we found high rates of Chlamydia trachomatis both at baseline and at repeat tests which suggests the possibility that this group might be continuing to engage in unsafe sexual practices. Given the extent of repeat testing and the high positivity rates on repeat testing, further research among this group is required to inquire into reasons for repeated testing.

Prediction of Chlamydia trachomatis infection to facilitate selective screening on population and individual level: a cross-sectional study of a population-based screening programme

OBJECTIVES

To develop prediction models for Chlamydia trachomatis (Ct) infection with different levels of detail in information, that is, from readily available data in registries and from additional questionnaires.

METHODS

All inhabitants of Rotterdam and Amsterdam aged 16-29 were invited yearly from 2008 until 2011 for home-based testing. Their registry data included gender, age, ethnicity and neighbourhood-level socioeconomic status (SES). Participants were asked to fill in a questionnaire on education, sexually transmitted infection history, symptoms, partner information and sexual behaviour. We developed prediction models for Ct infection using first-time participant data-including registry variables only and with additional questionnaire variables-by multilevel logistic regression analysis to account for clustering within neighbourhoods. We assessed the discriminative ability by the area under the receiver operating characteristic curve (AUC).

RESULTS

Four per cent (3540/80 385) of the participants was infected. The strongest registry predictors for Ct infection were young age (especially for women) and Surinamese, Antillean or sub-Saharan African ethnicity. Neighbourhood-level SES was of minor importance. Strong questionnaire predictors were low to intermediate education level, ethnicity of the partner (non-Dutch) and having sex with casual partners. When using a prediction model including questionnaire risk factors (AUC 0.74, 95% CI 0.736 to 0.752) for selective screening, 48% of the participating population needed to be screened to find 80% (95% CI 78.4% to 81.0%) of Ct infections. The model with registry risk factors only (AUC 0.67, 95% CI 0.656 to 0.675) required 60% to be screened to find 78% (95% CI 76.6% to 79.4%) of Ct infections.

CONCLUSIONS

A registry-based prediction model can facilitate selective Ct screening at population level, with further refinement at the individual level by including questionnaire risk factors.

The acceptability and cost of a home-based chlamydia retesting strategy: findings from the REACT randomised controlled trial

BACKGROUND

Chlamydia retesting three months after treatment is recommended to detect reinfections, but retesting rates are typically low. The REACT (retest after Chlamydia trachomatis) randomised trial demonstrated that home-based retesting using postal home-collection kits and SMS reminders, resulted in substantial improvements in retesting rates in women, heterosexual men and men who have sex with men (MSM), with detection of more repeat positive tests compared with SMS reminder alone. In the context of this trial, the acceptability of the home-based strategy was evaluated and the costs of the two strategies were compared.

METHODS

REACT participants (200 women, 200 heterosexual men, 200 MSM) were asked to complete an online survey that included home-testing acceptability and preferred methods of retesting. The demographics, sexual behaviour and acceptability of home collection were compared between those preferring home-testing versus clinic-based retesting or no preference, using a chi-square test. The costs to the health system of the clinic-based and home retesting strategies and the cost per infection for each were also compared.

RESULTS

Overall 445/600 (74 %) participants completed the survey; 236/445 from the home-testing arm, and 141 of these (60 %) retested at home. The majority of home arm retesters were comfortable having the kit posted to their home (86 %); found it easy to follow the instructions and collect the specimens (96 %); were confident they had collected the specimens correctly (90 %); and reported no problems (70 %). Most (65 %) preferred home retesting, 21 % had no preference and 14 % preferred clinic retesting. Comparing those with a preference for home testing to those who didn't, there were significant differences in being comfortable having a kit sent to their home (p = 0.045); not having been diagnosed with chlamydia previously (p = 0.030); and living with friends (p = 0.034). The overall cost for the home retest pathway was $154 (AUD), compared to $169 for the clinic-based retesting pathway and the cost per repeat infection detected was $1409 vs $3133.

CONCLUSIONS

Among individuals initially diagnosed with chlamydia in a sexual health clinic setting, home-based retesting was shown to be highly acceptable, preferred by most participants, and cost-efficient. However some clients preferred clinic-based testing, often due to confidentiality concerns in their home environment. Both options should be provided to maximise retesting rates.

TRIAL REGISTRATION

The trial was registered with the Australia New Zealand Clinical Trials Registry on September 9, 2011: ACTRN12611000968976.

An observational study to evaluate three pilot programmes of retesting chlamydia-positive individuals within 6 months in the South West of England

OBJECTIVES

To evaluate 3 pilot chlamydia retesting programmes in South West England which were initiated prior to the release of new National Chlamydia Screening Programme (NCSP) guidelines recommending retesting in 2014.

METHODS

Individuals testing positive between August 2012 and July 2013 in Bristol (n=346), Cornwall (n=252) and Dorset (n=180) programmes were eligible for inclusion in the retesting pilots. The primary outcomes were retest within 6 months (yes/no) and repeat diagnosis at retest (yes/no), adjusted for area, age and gender.

RESULTS

Overall 303/778 (39.0%) of participants were retested within 6 months and 31/299 (10.4%) were positive at retest. Females were more likely to retest than males and Dorset had higher retesting rates than the other areas.

CONCLUSIONS

More than a third of those eligible were retested within the time frame of the study. Chlamydia retesting programmes appear feasible within the context of current programmes to identify individuals at continued risk of infection with relatively low resource and time input.

Retesting young STI clinic visitors with urogenital Chlamydia trachomatis infection in the Netherlands; response to a text message reminder and reinfection rates: a prospective study with historical controls

OBJECTIVES

The objective of this study is to assess the effect of reminder text messages 6 months after the initial treatment on retest and chlamydia reinfection rates in young heterosexuals compared with a historical control group and to assess factors associated with both outcomes.

METHODS

Heterosexual people (aged 16-23 years), testing positive for urogenital chlamydia, were offered a retest after 6 months. Participants received a text message reminder at 6 months after the initial chlamydia diagnosis. Rates of retest uptake and the result of the retest were analysed using Cox regression. Prevalence ratios (PRs) were calculated to identify factors associated with these outcomes. Furthermore, the retest rate was compared with the retest rate of a historical control group.

RESULTS

30.6% (253/838) of the study group returned within 5-8 months compared with 9.2% (140/1530) in the historical control group. Women and persons who were not notified for a sexually transmitted infection (STI) at inclusion were more likely to return for a retest. 20.4% (56/275) of participants had a chlamydia reinfection upon retesting. Reinfection was higher in participants reporting STI-related symptoms (PR 3.2, 95% CI 1.8 to 5.6) and in participants who were notified for an STI at retest (PR 5.3, 95% CI 2.4 to 11.5).

CONCLUSIONS

A text message reminder appeared to have a clear, positive impact on the resulting retest rate. These results also indicate that retesting is necessary to identify chlamydia reinfections.

Dual Intervention to Increase Chlamydia Retesting: A Randomized Controlled Trial in Three Populations

INTRODUCTION

Chlamydia retesting 3 months after treatment is recommended to detect reinfections, but retesting rates are typically low. The purpose of this study is to determine if the addition of a postal home collection kit to a short message service (SMS) reminder at 3 months increases the percentage of patients retested for chlamydia at 1-4 months, compared to SMS alone.

DESIGN

In this unblinded randomized controlled trial, participants were randomized 1:1 to intervention (home arm) or control (clinic arm) status.

SETTING/PARTICIPANTS

Participants included 200 each of women, heterosexual men, and men who have sex with men diagnosed and treated for chlamydia at sexual health services.

INTERVENTION

Three months after chlamydia diagnosis, home arm participants received an SMS reminder and postal home collection kit (women, vaginal swab; heterosexual men, Copan UriSwab; men who have sex with men, UriSwab and rectal swab).

MAIN OUTCOME MEASURES

The main outcome measures were the percentage of participants retested at 1-4 months after chlamydia diagnosis and the percentage in each arm with repeat positive tests, by risk group and overall, analyzed by intention to treat. Data were collected from 2011 to 2013 and analyzed in 2014.

RESULTS

The percentage retested within 1-4 months of chlamydia diagnosis was significantly higher in home versus clinic arm participants among women (64% [66/103] vs 39% [38/97], p<0.001); heterosexual men (56% [57/101] vs 34% [34/99], p=0.002); men who have sex with men (62% [61/98] vs 44% [45/102], p=0.010); and overall (61% [184/302] vs 39% [117/298], p<0.001). The percentage in the home versus clinic arm with repeat positive tests was significantly higher among men who have sex with men (16% [16/98] vs 5% [5/102], p=0.021) and overall (10% [31/302] vs 4% [12/298], p=0.006).

CONCLUSIONS

The addition of a postal home collection kit to routine SMS reminders resulted in substantial improvements in chlamydia retesting rates in all three risk groups and detection of more repeat positive tests, compared with SMS alone. Extending the intervention to other primary care settings with low retesting rates should be considered.

Impact and cost-effectiveness of chlamydia testing in Scotland: a mathematical modelling study

Background

Chlamydia is the most common sexually transmitted bacterial infection in Scotland, and is associated with potentially serious reproductive outcomes, including pelvic inflammatory disease (PID) and tubal factor infertility (TFI) in women. Chlamydia testing in Scotland is currently targeted towards symptomatic individuals, individuals at high risk of existing undetected infection, and young people. The cost-effectiveness of testing and treatment to prevent PID and TFI in Scotland is uncertain.

Methods

A compartmental deterministic dynamic model of chlamydia infection in 15–24 year olds in Scotland was developed. The model was used to estimate the impact of a change in testing strategy from baseline (16.8% overall testing coverage; 0.4 partners notified and tested/treated per treated positive index) on PID and TFI cases. Cost-effectiveness calculations informed by best-available estimates of the quality-adjusted life years (QALYs) lost due to PID and TFI were also performed.

Results

Increasing overall testing coverage by 50% from baseline to 25.2% is estimated to result in 21% fewer cases in young women each year (PID: 703 fewer; TFI: 88 fewer). A 50% decrease to 8.4% would result in 20% more PID (669 additional) and TFI (84 additional) cases occurring annually. The cost per QALY gained of current testing activities compared to no testing is £40,034, which is above the £20,000-£30,000 cost-effectiveness threshold. However, calculations are hampered by lack of reliable data. Any increase in partner notification from baseline would be cost-effective (incremental cost per QALY gained for a partner notification efficacy of 1 compared to baseline: £5,119), and would increase the cost-effectiveness of current testing strategy compared to no testing, with threshold cost-effectiveness reached at a partner notification efficacy of 1.5. However, there is uncertainty in the extent to which partner notification is currently done, and hence the amount by which it could potentially be increased.

Conclusions

Current chlamydia testing strategy in Scotland is not cost-effective under the conservative model assumptions applied. However, with better data enabling some of these assumptions to be relaxed, current coverage could be cost-effective. Meanwhile, increasing partner notification efficacy on its own would be a cost-effective way of preventing PID and TFI from current strategy.

Electronic supplementary material

The online version of this article (doi:10.1186/1742-4682-12-2) contains supplementary material, which is available to authorized users.

Frequency and risk factors for incident and redetected Chlamydia trachomatis infection in sexually active, young, multi-ethnic women: a community based cohort study

Objective

To investigate the frequency and risk factors for incident and redetected Chlamydia trachomatis infection in sexually active, young, multi-ethnic women in the community.

Design

Cohort study.

Setting

20 London universities and Further Education colleges.

Participants

954 sexually experienced women, mean age 21.5 years (range 16–27), 26% from ethnic minorities, who were recruited to the Prevention of Pelvic Infection (POPI) chlamydia screening trial between 2004 and 2006, and returned repeat postal self-taken vaginal swabs 11–32 (median 16) months after recruitment.

Results

The estimated annual incidence of chlamydia infection among 907 women who tested negative at baseline was 3.4 per 100 person-years (95% CI 2.5 to 4.6 per 100 person-years), but 6.6 per 100 person-years (95% CI 4.5 to 9.3 per 100 person-years) in the 326 teenagers (<20 years). Predictors of incident chlamydia infection were age <20 years (relative risk (RR) 4.0, 95% CI 2.1 to 7.5), and (after adjusting for age) a new sexual partner during 12 months follow-up (RR 4.4, 95% CI 2.0 to 9.9), smoking (RR 2.2 95% CI 1.2 to 3.9), concurrent bacterial vaginosis (RR 2.0 95% CI 1.1 to 3.9) and high risk carcinogenic human papillomavirus (RR 2.2, 95% CI 1.1 to 4.3). Of 47 women positive for chlamydia at baseline, 12 (25.5%, 95% CI 13.9% to 40.3%) had redetected infection at a median of 16 months follow-up. Taking into account follow-up time (65 person-years), the annual redetection rate was 18.5 per 100 person-years (95% CI 9.9 to 30.0 per 100 person-years).

Conclusions

One in four women with chlamydia infection at baseline retested positive, supporting recent recommendations to routinely retest chlamydia positives.

Rationale and design of REACT: a randomised controlled trial assessing the effectiveness of home-collection to increase chlamydia retesting and detect repeat positive tests

BACKGROUND

Repeat infection with Chlamydia trachomatis is common and increases the risk of sequelae in women and HIV seroconversion in men who have sex with men (MSM). Despite guidelines recommending chlamydia retesting three months after treatment, retesting rates are low. We are conducting the first randomised controlled trial to assess the effectiveness of home collection combined with short message service (SMS) reminders on chlamydia retesting and reinfection rates in three risk groups.

METHODS/DESIGN

The REACT (retest after Chlamydia trachomatis) trial involves 600 patients diagnosed with chlamydia: 200 MSM, 200 women and 200 heterosexual men recruited from two Australian sexual health clinics where SMS reminders for retesting are routine practice. Participants will be randomised to the home group (3-month SMS reminder and home-collection) or the clinic group (3-month SMS reminder to return to the clinic). Participants in the home group will be given the choice of attending the clinic if they prefer. The mailed home-collection kit includes a self-collected vaginal swab (women), UriSWAB (Copan) for urine collection (heterosexual men), and UriSWAB plus rectal swab (MSM). The primary outcome is the retest rate at 1-4 months after a chlamydia diagnosis, and the secondary outcomes are: the repeat positive test rate; the reinfection rate; the acceptability of home testing with SMS reminders; and the cost effectiveness of home testing. Sexual behaviour data collected via an online survey at 4-5 months, and genotyping of repeat infections, will be used to discriminate reinfections from treatment failures. The trial will be conducted over two years. An intention to treat analysis will be conducted.

DISCUSSION

This study will provide evidence about the effectiveness of home-collection combined with SMS reminders on chlamydia retesting, repeat infection and reinfection rates in three risk groups. The trial will determine client acceptability and cost effectiveness of this strategy.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ACTRN12611000968976.

The chlamydia knowledge, awareness and testing practices of Australian general practitioners and practice nurses: survey findings from the Australian chlamydia control effectiveness pilot (ACCEPt)

Background

ACCEPt, a large cluster randomized control trial, aims to determine if annual testing for 16 to 29 year olds in general practice can reduce chlamydia prevalence. ACCEPt is the first trial investigating the potential role of practice nurses (PN) in chlamydia testing. To inform the design of the ACCEPt intervention, we aimed to determine the chlamydia knowledge, attitudes, and testing practices of participating general practitioners (GPs) and PNs.

Methods

GPs and PNs from 143 clinics recruited from 52 areas in 4 Australian states were asked to complete a survey at time of recruitment. Responses of PNs and GPs were compared using conditional logistic regression to account for possible intra cluster correlation within clinics.

Results

Of the PNs and GPs enrolled in ACCEPt, 81% and 72% completed the questionnaire respectively. Less than a third of PNs (23%) and GPs (32%) correctly identified the two age groups with highest infection rates in women and only 16% vs 17% the correct age groups in men. More PNs than GPs would offer testing opportunistically to asymptomatic patients aged ≤25 years; women having a pap smear (84% vs 55%, P<0.01); antenatal checkup (83% vs 44%, P<0.01) and Aboriginal men with a sore throat (79% vs 33%, P<0.01), but also to patients outside of the guideline age group at the time of the survey; 26 year old males presenting for a medical check (78% vs 30%, P = <0.01) and 33 year old females presenting for a pill prescription (83% vs 55%, P<0.01). More PNs than GPs knew that retesting was recommended after chlamydia treatment (93% vs 87%, P=0.027); and the recommended timeframe was 3 months (66% vs 26%, P<0.01). A high proportion of PNs (90%) agreed that they could conduct chlamydia testing in general practice, with 79% wanting greater involvement and 89% further training.

Conclusions

Our survey reveals gaps in chlamydia knowledge and management among GPs and PNs that may be contributing to low testing rates in general practice. The ACCEPt intervention is well targeted to address these and support clinicians in increasing testing rates. PNs could have a role in increasing chlamydia testing.