Adolescence and other risk factors for Chlamydia trachomatis genitourinary infection in women in Melbourne, Australia

High-resolution multilocus sequence typing reveals novel urogenital Chlamydia trachomatis strains in women in Mopani district, South Africa

OBJECTIVES

Recently, we reported a high prevalence (16%) of urogenital Chlamydia trachomatis infections among women in a rural setting in South Africa. Molecular epidemiological studies on C. trachomatis infections could provide insights into the characteristics of this epidemic, yet such data are not available. The objective of this study was therefore to assess the distribution of C. trachomatis strains among women from a South African rural community, the Mopani district, and to compare it with strains from Amsterdam, the Netherlands.

METHODS

High-resolution multilocus sequence typing (hr-MLST) was used to study urogenital C. trachomatis infections in women visiting primary healthcare facilities across rural Mopani District in Limpopo Province, South Africa. Sequence types (STs) were compared with 100 strains from women visiting the sexually transmitted infection clinic in Amsterdam, the Netherlands.

RESULTS

Full hr-MLST data were obtained for C. trachomatis infection in 43 women from Mopani district. Using the complete hr-MLST profile of all 43 women from Mopani district, 26 STs could be identified, of which 18 (69%) were novel to the hr-MLST database. The remaining STs clustered together with strains from Amsterdam.

CONCLUSIONS

Hr-MLST data revealed a diverse molecular epidemiology with novel STs and a specific cluster for the Mopani district. Also C. trachomatis types that occur worldwide were detected.

[Prevalence of Chlamydia trachomatis infection and factors with the risk of acquiring sexually transmitted infections in college students]

Chlamydia trachomatis genital infection is nowadays considered one of the most frequent causes of sexually transmitted infections (STI) in the world, mainly affecting the group of young people under 25 years old. The aim of this study was to determine the prevalence of C. trachomatis infection in newly admitted students to Universidad Nacional del Sur, Bahía Blanca, Argentina, and to evaluate the risk factors to acquire STI. For that purpose, 204 young college students with a mean age of 19 were involved in this study. Each participant delivered a sample of first-void urine and completed a questionnaire which was then submitted anonymously. The research for C. trachomatis was done on 114 valid samples through a technique of DNA amplification, whose molecular target was the gene ompA. Four cases of infection by C. trachomatis were detected with a prevalence of 3.5%. The risks factors associated to the infection were a history of 7 or more partners since the start of sexual activity and contact with a new sexual partner in the last 4 months. The prevalence of such infection reflects a moderate circulation of this microorganism in the studied population. This fact, along with some aspects shown by the questionnaire results, would characterize a population having a low risk profile for acquiring STIs. However, some other information obtained from the questionnaires gave some opposite evidence, which would alert us on the need of keeping watch, raising awareness and implementing preventive actions in this population.

To develop and measure the effectiveness and acceptability of a pharmacy-based chlamydia screening intervention in Australia

OBJECTIVES

To develop and measure the effectiveness and acceptability of a pharmacy-based chlamydia screening intervention called Emergency Contraception Mediated Pharmacy Access to Chlamydia Testing (ECOMPACT).

DESIGN

Selective, opportunistic and cross-sectional study targeting asymptomatic women requesting emergency contraception (EC).

SETTING

20 community pharmacies in the Perth metropolitan region, Australia.

METHODS

ECOMAPCT was developed through literature review and stakeholder consensus. Pharmacists were trained to offer ECOMPACT after the EC consultation. Women with signs and symptoms of sexually transmitted infections (STI) were referred to a physician for a full sexual health check. Asymptomatic women were offered a free ECOMPACT testing kit. The women self-collected a low-vaginal swab and returned their pathological specimen to designated drop-off sites. A pathology service analysed the specimens and sent the results to a sexual health physician. The effectiveness of ECOMPACT was determined by the uptake of the intervention and how well the target population was reached. An effective screening rate was calculated. Qualitative analysis was undertaken to understand acceptability issues from the perspective of the consumer and the pharmacists.

RESULTS

Of the 769 EC consultations in a 6-month period, 569 (78%) women were given information on chlamydia screening. All 247 (41%) agreed to participate. 81 (33%) of these women were ineligible. They were either symptomatic (n=33; 41%), or were under 18 years of age (n=48; 59%). Pharmacists successfully requested 166 (67%) pathology tests, of which 46 (28%) were returned to a pathology drop-off site. All tested negative for Chlamydia trachomatis. The effective screening rate was 6%. Consumers and pharmacists considered ECOMPACT to be highly convenient and the time taken to offer a chlamydia test along with an EC consultation as highly appropriate.

CONCLUSIONS

ECOMPACT was found to be simple, effective and acceptable. Given the opportunity, adequate training and support, community pharmacists in Australia were capable of requesting direct-to-consumer chlamydia tests.

The prevalence of Chlamydia trachomatis infection in Australia: a systematic review and meta-analysis

BACKGROUND

Chlamydia trachomatis is a common sexually transmitted infection in Australia. This report aims to measure the burden of chlamydia infection by systematically reviewing reports on prevalence in Australian populations.

METHODS

Electronic databases and conference websites were searched from 1997-2011 using the terms 'Chlamydia trachomatis' OR 'chlamydia' AND 'prevalence' OR 'epidemiology' AND 'Australia'. Reference lists were checked and researchers contacted for additional literature. Studies were categorised by setting and participants, and meta-analysis conducted to determine pooled prevalence estimates for each category.

RESULTS

Seventy-six studies met the inclusion criteria for the review. There was a high level of heterogeneity between studies; however, there was a trend towards higher chlamydia prevalence in younger populations, Indigenous Australians, and those attending sexual health centres. In community or general practice settings, pooled prevalence for women <25 years in studies conducted post-2005 was 5.0% (95% CI: 3.1, 6.9; five studies), and for men <30 years over the entire review period was 3.9% (95% CI: 2.7, 5.1; six studies). For young Australians aged <25 years attending sexual health, family planning or youth clinics, estimated prevalence was 6.2% (95% CI: 5.1, 7.4; 10 studies) for women and 10.2% (95% CI: 9.5, 10.9; five studies) for men. Other key findings include pooled prevalence estimates of 22.1% (95% CI: 19.0, 25.3; three studies) for Indigenous women <25 years, 14.6% (95% CI: 11.5, 17.8; three studies) for Indigenous men <25 years, and 5.6% (95% CI: 4.8, 6.3; 11 studies) for rectal infection in men who have sex with men. Several studies failed to report basic demographic details such as sex and age, and were therefore excluded from the analysis.

CONCLUSIONS

Chlamydia trachomatis infections are a significant health burden in Australia; however, accurate estimation of chlamydia prevalence in Australian sub-populations is limited by heterogeneity within surveyed populations, and variations in sampling methodologies and data reporting. There is a need for more large, population-based studies and prospective cohort studies to compliment mandatory notification data.

Correlates of Chlamydia trachomatis infection in a primary care sentinel surveillance network

Background Chlamydia is the most commonly notified infection in Australia. Prevention strategies should be informed by routine data on at-risk populations. Methods: We calculated chlamydia positivity and correlates of infection using multivariable logistic regression for data collected between April 2006 and June 2009. Results: Chlamydia positivity was 5.6% in 12 233 females, 7.7% in 10 316 heterosexual males and 6.2% in 7872 men who have sex with men (MSM). Correlates of chlamydia positivity among females included younger age (odds ratio (OR) 2.27, 95% confidence interval (CI) 1.92–2.69), being born overseas (OR 1.50, 95% CI 1.25–1.82), multiple sex partners in the past year (OR 1.72, 95% CI 1.40–2.11) and inconsistent condom use with regular sex partners (OR 3.44 ,95% CI 1.65–7.20). Sex work was protective for females (OR 0.68, 95% CI 0.53–0.86). Among heterosexual males, correlates of positivity were younger age (OR 1.87, 95% CI 1.62–2.17), being born overseas (OR 1.35, 95% CI 1.16–1.58), symptoms at the time of testing (OR 1.64, 95% CI 1.40–1.92) and multiple sex partners in the past year (OR 1.83, 95% CI 1.46–2.30). Correlates of positivity among MSM were being born overseas (OR 1.23, 95% CI 1.00–1.51), being HIV-positive (OR 1.80, 95%CI 1.32–2.47), and reporting six or more anal sex partners in the past 6 months (OR 4.45, 95% CI 1.37–14.5). Conclusions: Our analysis identified subgroups at the highest risk of chlamydia in Victoria. These estimates will provide important baseline information to measure the impact of chlamydia control strategies.

Epidemiological features and determinants for Chlamydia trachomatis infection among women in Catalonia, Spain

We determined the prevalence of Chlamydia trachomatis (CT) infection and risk factors for its acquisition by women aged less than 35 years who were attending sexual health centres in the province of Barcelona in 2007. A convenience sample of 397 adolescents and young adult women aged between 16 and 35 years, stratified by age and recruitment site, were tested using realtime polymerase chain reaction by CT DNA. A standardized questionnaire was used to collect epidemiological and behavioural data on the participants, which were analysed in a multivariate logistic regression model. The overall prevalence of CT was 4%, significantly higher in those under 25 years of age (5.8% versus 1.6% over 25). The independent risk factors for CT infection were: foreign origin (odds ratio [OR] 4.7; confidence interval [CI] 1.02-21.8), having had a sexual partner in the last three months (OR 4.59; CI 1.16-18.08) and tobacco use the last 12 months (OR 6.38; CI 1.16-34.93). In conclusion, this is the first study performed in Catalonia showing a high prevalence of CT in young women, consistent with trends in the rest of Europe. Systematic monitoring of CT infection in sentinel populations such as this will inform future targeted screening programmes in our setting.

'The difference in determinants of Chlamydia trachomatis and Mycoplasma genitalium in a sample of young Australian women'

BACKGROUND

Differences in the determinants of Chlamydia trachomatis ('chlamydia') and Mycoplasma genitalium (MG) genital infection in women are not well understood.

METHODS

A cohort study of 16 to 25 year old Australian women recruited from primary health care clinics, aimed to determine chlamydia and MG prevalence and incidence. Vaginal swabs collected at recruitment were used to measure chlamydia and MG prevalence, organism-load and chlamydia-serovar a cross-sectional analysis undertaken on the baseline results is presented here.

RESULTS

Of 1116 participants, chlamydia prevalence was 4.9% (95% CI: 2.9, 7.0) (n = 55) and MG prevalence was 2.4% (95% CI: 1.5, 3.3) (n = 27). Differences in the determinants were found - chlamydia not MG, was associated with younger age [AOR:0.9 (95% CI: 0.8, 1.0)] and recent antibiotic use [AOR:0.4 (95% CI: 0.2, 1.0)], and MG not chlamydia was associated with symptoms [AOR:2.1 (95% CI: 1.1, 4.0)]. Having two or more partners in last 12 months was more strongly associated with chlamydia [AOR:6.4 (95% CI: 3.6, 11.3)] than MG [AOR:2.2 (95% CI: 1.0, 4.6)] but unprotected sex with three or more partners was less strongly associated with chlamydia [AOR:3.1 (95%CI: 1.0, 9.5)] than MG [AOR:16.6 (95%CI: 2.0, 138.0)]. Median organism load for MG was 100 times lower (5.7 × 104/swab) than chlamydia (5.6 × 106/swab) (p < 0.01) and not associated with age or symptoms for chlamydia or MG.

CONCLUSIONS

These results demonstrate significant chlamydia and MG prevalence in Australian women, and suggest that the differences in strengths of association between numbers of sexual partners and unprotected sex and chlamydia and MG might be due to differences in the transmission dynamics between these infections.

Chlamydia at an inner metropolitan sexual health service in Sydney, NSW: Australian Collaboration for Chlamydia Enhanced Sentinel Surveillance (ACCESS) Project

Background: Australia has a widely dispersed network of public sexual health services that test large numbers of people from high prevalence populations for genital Chlamydia trachomatis infection. These populations include young sexually active heterosexuals, men who have sex with men, sex workers and Aboriginal and Torres Strait Islander people. The Australian Collaboration for Chlamydia Enhanced Sentinel Surveillance (ACCESS) Project was established to monitor chlamydia testing rates and positivity rates at a national level, which in turn will help interpret trends in chlamydia diagnoses reported through passive surveillance. The ACCESS Project is the first time that chlamydia-related data including priority population and testing denominators has been collated at a national level. The present paper reports on chlamydia testing and positivity rates in a sexual health service in the inner west of Sydney between 2004 and 2008 and compares these to published national data from the ACCESS Project in sexual health services. Methods: Chlamydia positivity and testing rates at an inner western Sydney sexual health service were compared with aggregate data from the ACCESS Project obtained from 14 sexual health services across Australia. Using a standardised extraction program, retrospective de-identified line-listed demographic and chlamydia testing data on all patients were extracted from patient management systems. Results: Over the 5-year period, 5145 new patients attended the inner-west sexual health service. Almost 66% had a chlamydia test at first visit and there was no significant difference in this testing rate when compared with the ACCESS Project national rate for sexual health services (67.0%; odds ratio [OR] 0.94, 95% confidence intervals 0.88–1.00). The testing rate increased over time from 61% in 2004 to 70% in 2008. There were 281 chlamydia diagnoses at this service, giving an overall chlamydia positivity rate of 9.3%, significantly higher than the ACCESS Project national rate of 8.2% (OR 1.16, 95% confidence intervals 1.02–1.32). Discussion: Testing rates were similar and positivity rates for Chlamydia trachomatis were higher in this sexual health service in Sydney than national trends.

Role of the general practitioner in testing for genital Chlamydia trachomatis infection: an analysis of enhanced surveillance data

BACKGROUND

To examine the relationship between genital chlamydia testing by healthcare providers and patient demographic characteristics in Tasmania, Australia, from 2001 to 2007.

METHODS

Analysis of enhanced surveillance data for genital Chlamydia trachomatis infections notified to the Tasmanian Communicable Diseases Prevention Unit between 1 January 2001 and 31 December 2007.

RESULTS

General practitioners identify most cases of genital chlamydia infection, irrespective of patient age, gender, indigenous status or urban status. Tests that are performed for screening purposes identify the largest number of cases in females, particularly in very young females. In males, tests performed due to the presence of clinical symptoms identify the majority of cases. However, tests performed for the purposes of contact tracing also identify a substantial burden of genital chlamydia infection, particularly in males.

CONCLUSIONS

The present study demonstrates the critical role the general practitioner has in the identification of genital chlamydia infection. Opportunistic screening for genital chlamydia, including in the context of contact tracing, is an essential clinical activity that results in the identification of substantial numbers of cases of infection. Policy makers and public health practitioners should support general practice screening initiatives and remove the barriers to genital chlamydia screening in general practice.

What needs to change to increase chlamydia screening in general practice in Australia? The views of general practitioners

Background

Australia is considering implementing a chlamydia screening program in general practice. The views of general practitioners (GPs) are necessary to inform the design of the program. This paper aimed to investigate Australian GPs' views on how chlamydia screening could work in the Australian context.

Methods

This project used both qualitative interviews and a quantitative questionnaire. GPs were randomly selected from a national database of medical practitioners for both the qualitative and quantitative components. Semi-structured interviews were conducted with GPs and a thematic analysis conducted. The results of the interviews were used to design a quantitative postal questionnaire for completion by a larger sample of GPs. Up to three reminders were sent to non-responders.

Results

Twenty one GPs completed an interview and 255 completed the postal questionnaire. The results of the postal survey were in strong concordance with those of the interview. GPs identified a number of barriers to increased screening including lack of time, knowledge of GPs and the public about chlamydia, patient embarrassment and support for partner notification. GPs felt strongly that screening would be easier if there was a national program and if the public and GPs had a greater knowledge about chlamydia. Incentive payments and mechanisms for recall and reminders would facilitate screening. Greater support for contact tracing would be important if screening is to increase.

Conclusion

Chlamydia screening in general practice is acceptable to Australian GPs. If screening is to succeed, policy makers must consider the facilitators identified by GPs.

A chlamydia prevalence survey of young women living in Melbourne, Victoria

BACKGROUND

To estimate the population-based chlamydia prevalence among women aged 18 to 35 years living in Melbourne, Victoria, and to assess the feasibility of using mailed urine specimens to test women.

METHODS

A simple random sample of 11,001 households in Melbourne was selected from the telephone directory. Participants completed telephone interviews and provided urine specimens through the mail for chlamydia testing. Urines were tested using polymerase chain reaction.

RESULTS

11,001 households were contacted, with 1532 households identified as including eligible women; telephone interviews were completed, with 979 women giving a response rate of 64%. Six hundred and fifty-seven women provided a urine specimen with a response rate of 43%. Among sexually active women aged 18-24 years, the chlamydia prevalence was 3.7% (95% CI: 1.2%, 8.4%) and 0.2% (95% CI: 0.0%, 1.1%) among 25-35 year olds. Chlamydia prevalence increased significantly with an increasing number of male sexual partners.

CONCLUSIONS

This is the first study of its kind in Australia and shows that chlamydia prevalence increases with an increasing number of male sexual partners in the last 12 months. Mailed urine specimens are feasible for conducting population-based chlamydia-prevalence surveys but it is difficult to obtain high response rates with this methodology. Public health resources should now be directed towards investigating how to reach young women at increased risk of infection, ensuring that they are tested for chlamydia.

Prevalence of Chlamydia trachomatis infection among 'high risk' young people in New South Wales

International research on homeless adolescents has found that incidence and prevalence of sexually transmissible infections is relatively high. This study reports on a chlamydia prevalence survey conducted among high-risk young people (14-25 years) in New South Wales. The participants were recruited from youth health centres, which target homeless and high-risk youth. Of 333 clients (42.6% male), 84.1% were sexually active and mean number of sexual partners over the preceding 3 months was 1.4. Among sexually active participants, 24.6% claimed to use condoms always and 25% never. Sixteen of 274 available urine samples tested positive for Chlamydia trachomatis infection. Further research is warranted to better define high-risk groups and clarify the nature of associations between various factors impacting on sexual health. Most importantly, research is now called for into effective strategies for engaging and attracting young people to screening, treatment and contact tracing.

Diagnosis of sexually transmitted infections (STI) using self-collected non-invasive specimens

Paramount in control of transmission of sexually transmitted infections (STIs) is their prompt recognition and appropriate treatment. In countries where definitive diagnoses are difficult, a 'syndromic approach' to management of STIs is recommended and practiced, yet many STIs have common symptoms or are asymptomatic and therefore go undetected and untreated. This is of particular concern with the recognition that HIV transmission is increased with co-existent STIs: the attributable risk for each STI varying with the prevalence within a particular population. Hence, HIV public health prevention approaches must include STI preventative strategies to be effective. Even then, microbiological screening is incorporated into STI control strategies; lack of access to appropriate services (especially in rural and remote areas), reluctance of at-risk populations to attend for treatment, fear of invasive genital examinations, and lower sensitivities of conventional diagnostic assays reduces the effectiveness of such programmes. Therefore, accurate, cost-effective, reliable diagnostic assays (preferably those which can be used in the field) are needed to impact on the incidence of the various STIs, as well as HIV. With the advent of molecular technologies, including target and signal amplification methods, diagnoses of STIs have been revolutionised and allow the use of non or minimally invasive sampling techniques, some of which are self-collected by the patient, e.g. first-void urine, cervico-vaginal lavage, low vaginal swabs, and tampons. Most studies evaluating such self-sampling with molecular diagnostic techniques have demonstrated an equivalent or superior detection of STIs as compared to conventional sampling and detection methods. These sampling methods can also be used to determine prevalence of STIs in various populations, but particularly those with difficult access to medical care. In this article, the utility of self-sampling collection devices for detection of various STIs, particularly in women, is reviewed as one step towards formulating appropriate strategies in control of STIs, and which are especially suited for remote areas.

Chlamydia trachomatis infection in the family planning clinical setting across New South Wales

Background: Following a small pilot study in 2003, a study was set up to determine the prevalence of genital Chlamydia trachomatis infection in young women presenting to Family Planning NSW centres across New South Wales and to evaluate the characteristics of those infected. Methods: A cross-sectional survey of 621 consecutive women aged from 16 to 24 years was carried out over a 3-month period in 2004 at five Family Planning NSW centres. Urine samples were tested for C. trachomatis using the polymerase chain reaction (PCR) method. Women with a positive result were reviewed and treated. Results: Of 925 eligible clients, 621 (67%) were recruited to the study. Chlamydia trachomatis was detected in 35 of the 621 recruits (5.6%, 95% CI 3.8–7.4). The prevalence at the Hunter centre was significantly higher than the combined prevalence at the other four participating centres (9.7% compared with 3.9%; P = 0.008). Two characteristics were identified as independent predictors of infection in this study: ‘reporting a recent change of partner in the past three months’ (crude odds ratio (OR) 3.33, 95% CI 1.67–6.64) and ‘reporting three or more partners in the past year’ (crude OR 3.69, 95% CI 1.83–7.46). Reported condom use, a history of one or more sexually transmissible infections and current combined oral contraceptive pill use were not associated with infection in this study. Conclusions: The prevalence of C. trachomatis infection is sufficiently high to support targeted testing of 16–24-year-old women in the Family Planning NSW setting and informs the development of a national screening strategy.

Modelling the impact of opportunistic screening on the sequelae and public healthcare costs of infection with Chlamydia trachomatis in Australian women

OBJECTIVES

To describe the health outcomes and public healthcare costs of a single screening for Chlamydia trachomatis in Australian women aged 15-34 years.

METHODS

A decision analytic model was used to determine the epidemiological estimates of prevalence and costs of C. trachomatis infection and its diagnosis, treatment and sequelae.

RESULTS

We estimate that in any female population in Australia, with a Chlamydia prevalence rate of 5.7% or higher, a single screening examination for Chlamydia is cost saving for the public healthcare system.

CONCLUSIONS

We found that opportunistic screening of high-risk populations is likely to be cost saving to the public healthcare system, although there is not sufficient evidence to support periodic population screening. As our model uses conservative epidemiological and public healthcare cost estimates, the health and financial impacts of C. trachomatis used in the model may be an underestimate of the true costs of infection.

Screening injecting drug users for sexually transmitted infections and blood borne viruses using street outreach and self collected sampling

BACKGROUND

Injecting drug users (IDUs) are a marginalised population, who infrequently access health services for screening for sexually transmitted infections (STIs) and blood borne viruses (BBVs), and are at high risk of these infections.

OBJECTIVES

To use street outreach and self collection of samples for STI screening, to establish the prevalence of BBVs and STIs, and to identify risk behaviours among a group of culturally diverse street based IDUs.

METHODS

This was a cross sectional study of 314 IDUs in the central business district of Melbourne, Australia, conducted over 3 years (1999-2002). We used street outreach as the recruitment strategy with staff "on foot" in injecting and dealing locations, as well as self collected genital sampling to increase acceptance of screening for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis by polymerase chain reaction (PCR). Individuals were screened for hepatitis A, B, and C, syphilis and HIV, and given the option of a self collected or clinician collected blood sample to increase acceptance of screening for BBVs.

RESULTS

Street outreach was highly effective and self directed STI sampling was more acceptable than practitioner directed sampling (76% versus 9% acceptance, p<0.001). There was a high prevalence of hepatitis C (74%, 95% CI 69 to 79), STIs (8% (5 to 13)), and chlamydia (6% (3 to 10)), and past exposure to hepatitis A and B was common. High rates of recent sharing of injecting equipment, unprotected sex and casual sexual partners, together with low levels of awareness of current hepatitis C infection were identified.

CONCLUSION

Street outreach and self collected genital samples facilitate screening for STIs and BBVs in IDUs and revealed a high prevalence of infections and risk behaviours.

The prevalence of genital Chlamydia trachomatis in Australia 1997 - 2004: a systematic review

Objectives: To determine by systematic review the prevalence of genital chlamydial infection in Australia between 1997 and 2004. Methods: Electronic literature databases, reference lists, and conference proceedings were searched and health agencies and jurisdictions were contacted for published and unpublished reports. Studies were eligible if they offered a diagnostic nucleic acid amplification test to consecutive individuals presenting during the study period. As a summary measure of the available data, mean prevalence rates, weighted by sample size and irrespective of participant age, were calculated for the population sub-groups. Results: 40 studies of 50 populations and 40587 individuals met the inclusion criteria, but only one of these was population-based. The use of non-systematic methodologies prevented an assessment of time trends and a statistical comparison of population sub-groups. The mean overall prevalence of genital chlamydial infection was 4.6% (95% CI 4.4–4.8%), reflecting over-sampling of high-risk groups. The mean community-based rates were 7.5% (95% CI 6.4–8.6%) and 8.7% (95% CI 7.9–9.7%) for Indigenous men and women, and 1.5% (95% CI 1.1–1.9%) and 1.4% (95% CI 0.9–2.0%) for non-Indigenous men and women. The overall mean estimates for other groups were 3.3% (95% CI 3.0–3.7%) for female attendees of sexual health and related clinics, 5.6% (95% CI 4.9–6.4%) for adolescents and young adults, 3.3% (95% CI 2.8–3.9%) for sex workers, and 1.6% (95% CI 1.2–2.0%) for urethral infection in men who have sex with men. Clinic-based estimates were generally, although not consistently, higher than community-based estimates. There is no serial population-based data for sexually active young men and women, but the available age-specific rates suggest under-ascertainment by the routine surveillance systems. Conclusions: The prevalence of genital chlamydial infection in Indigenous Australians and young adults is unacceptably high and quality epidemiological studies are urgently required to supplement the routinely collected national notification data.

Do the characteristics of sexual health centre clients predict chlamydia infection sufficiently strongly to allow selective screening?

Objectives: This study aimed to estimate chlamydia prevalence and risk factors for infection and to assess the performance of chlamydia-selective screening criteria among clients attending a large sexually transmitted infection (STI) clinic. Methods: Computerised records for all attendances between 1 July 2002 and 30 June 2003 were analysed. Chlamydia prevalence and risk factors for infection were determined for all new clients. The sensitivity and specificity of risk factors for chlamydia were assessed. Results: 2642 male and 2084 female new clients were tested for chlamydia with a prevalence of 7.3% (95% CI: 6.3%, 8.4%) among men and 3.9% (95% CI: 3.1%, 4.9%) among women. Screening heterosexual men based on a positive contact or symptoms of non-specific urethritis or any two of age < 25 years, 4+ partners last 12 months, inconsistent condom use or not presenting for an asymptomatic screen detected 88% of infections by screening 62%. Screening women based on a positive contact or injecting drug use or any two of age < 25 years, 2+ partners last 12 months or inconsistent condom use would detect 86% of infections by screening 57%. Conclusions: Selective screening could be used to more efficiently identify heterosexual men and women at risk of chlamydia.

Prevalence of Chlamydia trachomatis infection among women in a Middle Eastern community

BACKGROUND: Common vaginal infections that manifest in women are usually easily diagnosed. However, Chlamydia infection is often asymptomatic, leading to infertility before it is detected. If it occurs in pregnancy, it could lead to significant neonatal morbidity. It may also play a role with other viral infections for e.g. Human Papilloma Virus in the development of cervical cancer. The objective of this study was to determine the prevalence of Chlamydia infection in women undergoing screening for cervical abnormalities as a part of a research project in primary and secondary care institutions in the United Arab Emirates. METHODS: In this cross sectional study married women attending primary and secondary care participating in a large nationwide cervical abnormalities screening survey were offered Chlamydia testing using a commercially available test kit. This kit uses a rapid immunoassay for the direct detection of Chlamydia trachomatis antigen in endocervical swab specimens. As this study was performed in a traditional Islamic country, unmarried women were excluded from testing, as the management of any positive cases would create legal and social problems. All married women consenting to take part in the study were included irrespective of age. RESULTS: Of 1039 women approached over a period of eight months 919 (88.5%) agreed to participate. The number of women in the 16 to 19 years was small (0.01%) and 30% were aged over 40 years. The prevalence of Chlamydia infection in this study was 2.6% (95% confidence interval 1.2-3.3%), which was marginally higher in women screened in secondary care (p = 0.05). CONCLUSION: This is one of the few reports on the prevalence of Chlamydia infection in women from the Middle East. Due to cultural and social constraints this study excluded a large proportion of women aged less than 19 years of age. Hence no direct comparisons on prevalence could be made with studies from the West, which all included younger women at high risk of Chlamydia. However this study emphasizes the importance of cultural factors while interpreting results of studies from different cultures and communities.

Genital Chlamydia trachomatis infection in Australia: epidemiology and clinical implications

Over the last decade, notification rates for genital Chlamydia trachomatis infection in Australia have been rising progressively. While chlamydia is common and possibly increasing in the general population, heterosexual adolescents, indigenous Australians in remote settings, and homosexually active men are at particular risk of infection. Few studies are available on the extent of morbidity from chlamydia-associated diseases. Australia urgently needs a national strategy to control chlamydia, with widespread, selective screening as a key component. As general practitioners have an important role to play, we proffer guidelines for selective testing in primary care.

The tip of the iceberg: opportunistic screening for Chlamydia trachomatis in asymptomatic patients attending a young people's health clinic reveals a high prevalence — a pilot study

Objectives: We implemented an opportunistic screening programme for Chlamydia trachomatis amongst patients presenting to a young peoples’ health service in the city of Geelong, Australia, to define the prevalence of infection and to identify specific risk factors. Methods: Over a 7-month period sexually active patients attending the young peoples’ clinic were offered C. trachomatis screening by nucleic acid amplification test. There was 100% acceptance rate among those offered the test. Patient demographics, reason for presentation at the clinic and reported symptoms were documented by the clinicians and correlated with laboratory findings. Results: 163 patients between the ages of 12–25 were tested, nine males and 154 females. The prevalence of chlamydia infection was 5.8% and was highest (16.0%) among patients presenting for the morning after pill. Inhibition of the nucleic acid amplification test occurred in 11.0% of urine samples. All patients with inhibited tests were asked to provide a repeat sample for retesting, but only 50% complied with this request. The majority of repeat samples (88.9%) had no inhibitors present and yielded a negative result. There was no correlation between symptoms and a positive chlamydia result. Conclusions: Chlamydia infection is common in young people engaging in unsafe sexual practice and cannot be predicted by the presence of symptoms. The high prevalence of infection in Geelong would make screening cost effective in this age group. Ongoing population screening of sexually active young people should be encouraged in community health centres. Inhibition of the nucleic acid amplification test was common but repeat testing of urine a few days later usually gave satisfactory results.