Population attributable risk for chlamydia infection in a cohort of young international travellers (backpackers) and residents in Australia

Aim To estimate the population attributable risk (PAR) for Chlamydia trachomatis infection in young men and women in Sydney, Australia.Method Multivariate logistic regression was used to examine the association between demographic, sexual behaviour and other potential risk factors and chlamydia positivity in young (¡Ü30 years) heterosexual international travellers (backpackers) and Australian residents attending a sexual health clinic. Point and interval estimates of PAR were calculated to quantify the proportion of chlamydia infections that can theoretically be prevented if a combination of risk factors is eliminated from a target population.Results In males, the PAR associated with inconsistent condom use in the past 3 months was 65% (95% CI 56% to 71%) in backpackers compared to 50% (95% CI 41% to 56%) in non-backpackers and the PAR associated with reporting three or more female sexual partners in the past 3 months was similar between male backpackers and non-backpackers (33% (95% CI 28% to 40%) and 36% (95% CI 32% to 41%), respectively). In females, the PAR associated with inconsistent condom use in the past 3 months was 51% (95% CI 42% to 59%) in backpackers compared to 41% (95% CI 31% to 51%) in non-backpackers, and the PAR associated with reporting three or more male sexual partners in the past 3 months was 14% (95% CI 11% to 18%) in backpackers compared to 30% (95% CI 25% to 37%) in non-backpackers.Conclusion These findings suggest that the largest number of chlamydia infections could be avoided by increasing condom use, particularly in backpackers. Reporting multiple partners was also associated with a large proportion of infections and the risk associated with this behaviour should be considered in health promotion strategies

Chlamydia trachomatis and the risk of spontaneous preterm birth, babies who are born small for gestational age, and stillbirth: A population-based cohort study

Background: Chlamydia trachomatis is one of the most commonly diagnosed sexually transmitted infections worldwide, but reports in the medical literature of an association between genital chlamydia infection and adverse obstetric outcomes are inconsistent. Methods: The Western Australia Data Linkage Branch created a cohort of women of reproductive age by linking records of birth registrations with the electoral roll for women in Western Australia who were born from 1974 to 1995. The cohort was then linked to both chlamydia testing records and the state perinatal registry for data on preterm births and other adverse obstetric outcomes. We determined associations between chlamydia testing, test positivity, and adverse obstetric outcomes using multivariate logistic regression analyses. Findings: From 2001 to 2012, 101558 women aged 15 to 38 years had a singleton birth. Of these women, 3921 (3·9%) had a spontaneous preterm birth, 9762 (9·6% of 101371 women with available data) had a baby who was small for gestational age, and 682 (0·7%) had a stillbirth. During their pregnancy, 21267 (20·9%) of these women had at least one chlamydia test record, and 1365 (6·4%) of those tested were positive. Before pregnancy, 19157 (18·9%) of these women were tested for chlamydia, of whom 1595 (8·3%) tested positive for chlamydia. Among all women with a test record, after adjusting for age, ethnicity, maternal smoking, and history of other infections, we found no significant association between a positive test for chlamydia and spontaneous preterm birth (adjusted odds ratio 1·08 [95% CI 0·91–1·28]; p=0·37), a baby who was small for gestational age (0·95 [0·85–1·07]; p=0·39), or stillbirth (0·93 [0·61–1·42]; p=0·74). Interpretation: A genital chlamydia infection that is diagnosed and, presumably, treated either during or before pregnancy does not substantially increase a woman’s risk of having a spontaneous preterm birth, having a baby who is small for gestational age, or having a stillbirth. Funding: Australian National Health and Medical Research Counci

Molecular antimicrobial resistance surveillance for neisseria gonorrhoeae, Northern Territory, Australia

Neisseria gonorrhoeae antimicrobial resistance (AMR) is a globally recognized health threat; new strategies are needed to enhance AMR surveillance. The Northern Territory of Australia is unique in that 2 different first-line therapies, based primarily on geographic location, are used for gonorrhea treatment. We tested 1,629 N. gonorrhoeae nucleic acid amplification test–positive clinical samples, collected from regions where ceftriaxone plus azithromycin or amoxicillin plus azithromycin are recommended first-line treatments, by using 8 N. gonorrhoeae AMR PCR assays. We compared results with those from routine culture-based surveillance data. PCR data confirmed an absence of ceftriaxone resistance and a low level of azithromycin resistance (0.2%), and that penicillin resistance was \u3c5% in amoxicillin plus azithromycin regions. Rates of ciprofloxacin resistance and penicillinase-producing N. gonorrhoeae were lower when molecular methods were used. Molecular methods to detect N. gonorrhoeae AMR can increase the evidence base for treatment guidelines, particularly in settings where culture-based surveillance is limited

Improving adherence to guidelines for the diagnosis and management of pelvic inflammatory disease: a systematic review

Background Evidence suggests adherence to clinical guidelines for pelvic inflammatory disease (PID) diagnosis and management is suboptimal. We systematically reviewed the literature for studies describing strategies to improve the adherence to PID clinical guidelines. Methods. The databases MEDLINE and EMBASE, and reference lists of review articles were searched from January 2000 to April 2012. Only studies with a control group were included. Results. An interrupted time-series study and two randomised controlled trials (RCTs) were included. The interrupted time-series found that following a multifaceted patient and practitioner intervention (practice protocol, provision of antibiotics on-site, written instructions for patients, and active followup), more patients received the recommended antibiotics and attended for followup. One RCT found a patient video on PID self-care did not improve medication compliance and followup. Another RCT found an abbreviated PID treatment guideline for health-practitioners improved their management of PID in hypothetical case scenarios but not their diagnosis of PID. Conclusion. There is limited research on what strategies can improve practitioner and patient adherence to PID diagnosis and management guidelines. Interventions that make managing PID more convenient, such as summary guidelines and provision of treatment on-site, appear to lead to better adherence but further empirical evidence is necessary

Long-term impact of childhood hepatitis B vaccination programs on prevalence among Aboriginal and non-Aboriginal women giving birth in Western Australia

Background/Aims: To evaluate the long-term effect of infant and childhood hepatitis B (HBV) vaccination programs among birthing women in Western Australia. Methods: A cohort of Western Australian women born from 1974 to 1995 was created using Birth Registrations and Electoral Roll records. They were linked to a perinatal register and notifiable diseases register to identify women having respectively their first births between 2000 and 2012 and diagnoses of HBV infections. HBV prevalence was estimated in Aboriginal and non-Aboriginal women, and according to maternal birth year cohorts. Results: Of 66,073 women, 155 (0.23%) had a linked non-acute HBV notification. HBV prevalence was five times higher in Aboriginal women compared to their non-Aboriginal counterparts (0.92%, 95%CI 0.65–1.18 versus 0.18%, 0.15–0.21). Among Aboriginal women, after adjusting for year of giving birth and region of residence, those born in the targeted infant and school-based vaccination era (maternal year of birth 1988–1995) had an 89% lower risk (adjusted odds ratio [aOR] 0.11, 0.04–0.33) of HBV than those born in the pre-vaccination era (1974–1981). Prevalence also differed between Aboriginal women residing in rural/remote areas compared to those in major cities (aOR 3.06, 1.36–6.88). Among non-Aboriginal women, no significant difference in HBV prevalence was observed by maternal birth cohort (p = 0.20) nor by residence (p = 0.23), but there were significant differences by ethnicity with a 36-fold higher prevalence (aOR 36.08, 22.66–57.46) in non-Caucasian versus Caucasian women. Conclusions: A significant decline in HBV prevalence in Aboriginal birthing mothers was observed following the introduction of HBV vaccination programs in Western Australia. There were also considerable disparities in prevalence between women by area of residence and ethnicity. Our findings reflect those observed in women in other Australian jurisdictions. Continued surveillance of HBV prevalence in birthing mothers will provide ongoing estimates of HBV vaccination program impact across Australia and the populations most at risk of chronic HBV

Psychological distress among re-education through labour camp detainees in Guangxi Autonomous Region, China

There is currently no information about the prevalence of, and factors contributing to psychological distress experienced by re-education through labour camp detainees in China. [Methods:] A cross-sectional face-to-face survey was conducted in three labour camps in Guangxi, China. The questionnaire covered socio-demographic characteristics; sexually transmissible infections (STIs); drug use; psychological distress (K-10); and health service usage and access inside the labour camps. K-10 scores were categorised as ≤30 (low to moderate distress) and  >30 or more (highly distressed). Univariate and multivariate logistic regression models identified factors independently associated with high K-10 scores for men and women separately. [Results:] In total, 755 detainees, 576 (76%) men and 179 (24%) women, participated in the health survey. The study found 11.6% men versus 11.2% women detainees experienced high psychological distress, but no significant gender differences were observed (p> 0.05). Multivariate logistic regression showed that multiple physical health problems were significantly associated with high psychological distress among men. [Conclusion:] Drug treatment and forensic mental health services need to be established in detention centres in China to treat more than 10% of detainees with drug use and mental health disorders

Using population attributable risk to choose HIV prevention strategies in men who have sex with men

<p>Abstract</p> <p>Background</p> <p>In Australia, HIV is concentrated in men who have sex with men (MSM) and rates have increased steadily over the past ten years. Health promotion strategies should ideally be informed by an understanding of both the prevalence of the factors being modified, as well as the size of the risk that they confer. We undertook an analysis of the potential population impact and cost saving that would likely result from modifying key HIV risk factors among men who have sex with men (MSM) in Sydney, Australia.</p> <p>Methods</p> <p>Proportional hazard analyses were used to examine the association between sexual behaviours in the last six months and sexually transmissible infections on HIV incidence in a cohort of 1426 HIV-negative MSM who were recruited primarily from community-based sources between 2001 and 2004 and followed to mid-2007. We then estimated the proportion of HIV infections that would be prevented if specific factors were no longer present in the population, using a population attributable risk (PAR) method which controls for confounding among factors. We also calculated the average lifetime healthcare costs incurred by the HIV infections associated with specific factors by estimating costs associated with clinical care and treatment following infection and discounting at 3% (1% and 5% sensitivity) to present value.</p> <p>Results</p> <p>Unprotected anal intercourse (UAI) with a known HIV-positive partner was reported by 5% of men, the hazard ratio (HR) was 16.1 (95%CI:6.4-40.5), the PAR was 34% (95%CI:24-44%) and the average lifetime HIV-related healthcare costs attributable to UAI with HIV-positive partners were $AUD102 million (uncertainty range:$93-114 m). UAI with unknown HIV status partners was reported by 25% of men, the HR was 4.4 (95%CI:1.8-11.2), the PAR was 33% (95%CI:26-42%) and the lifetime incurred costs were $AUD99 million. Anal warts prevalence was 4$AUD39 million.</p> <p>Conclusions</p> <p>Our analysis has found that although UAI with an HIV-positive sexual partner is a relatively low-prevalence behaviour (reported by 5% of men), if this behaviour was not present in the population, the number of infections would be reduced by one third. No other single behaviour or sexually transmissible infections contributes to a greater proportion of infections and HIV-related healthcare costs.</p

Intensified partner notification and repeat testing can improve the effectiveness of screening in reducing Chlamydia trachomatis prevalence: a mathematical modelling study.

BACKGROUND The Australian Chlamydia Control Effectiveness Pilot (ACCEPt) was a cluster randomised controlled trial designed to assess the effectiveness of annual chlamydia testing through general practice in Australia. The trial showed that testing rates increased among sexually active men and women aged 16-29 years, but after 3 years the estimated chlamydia prevalence did not differ between intervention and control communities. We developed a mathematical model to estimate the potential longer-term impact of chlamydia testing on prevalence in the general population. METHODS We developed an individual-based model to simulate the transmission of Chlamydia trachomatis in a heterosexual population, calibrated to ACCEPt data. A proportion of the modelled population were tested for chlamydia and treated annually at coverage achieved in the control and intervention arms of ACCEPt. We estimated the reduction in chlamydia prevalence achieved by increasing retesting and by treating the partners of infected individuals up to 9 years after introduction of the intervention. RESULTS Increasing the testing coverage in the general Australian heterosexual population to the level achieved in the ACCEPt intervention arm resulted in reduction in the population-level prevalence of chlamydia from 4.6% to 2.7% in those aged 16-29 years old after 10 years (a relative reduction of 41%). The prevalence reduces to 2.2% if the proportion retested within 4 months of treatment is doubled from the rate achieved in the ACCEPt intervention arm (a relative reduction of 52%), and to 1.9% if the partner treatment rate is increased from 30%, as assumed in the base case, to 50% (a relative reduction of 59%). CONCLUSION A reduction in C. trachomatis prevalence could be achieved if the level of testing as observed in the ACCEPt intervention arm can be maintained at a population level. More substantial reductions can be achieved with intensified case management comprising retesting of those treated and treatment of partners of infected individuals

Risk of pelvic inflammatory disease in relation to chlamydia and gonorrhea testing, repeat testing, and positivity: A population-based cohort study

Background: There is uncertainty around whether the risks of pelvic inflammatory disease (PID) differ following Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infection. We quantified the risk of PID associated with chlamydia and gonorrhea infection and subsequent repeat infections in a whole-population cohort. Methods: A cohort of 315123 Western Australian women, born during 1974–1995, was probabilistically linked to chlamydia and gonorrhea testing records and to hospitalizations and emergency department presentations for PID from 2002 to 2013. Time-updated survival analysis was used to investigate the association between chlamydia and gonorrhea testing, and positivity, and risk of PID. Results: Over 3199135 person-years, 120748 women had pathology test records for both chlamydia and gonorrhea, 10745 chlamydia only, and 653 gonorrhea only. Among those tested, 16778 (12.8%) had ≥1 positive chlamydia test, 3195 (2.6%) ≥1 positive gonorrhea test, and 1874 (1.6%) were positive for both. There were 4819 PID presentations (2222 hospitalizations, 2597 emergency presentations). Adjusting for age, Aboriginality, year of follow-up, health area, and socioeconomic status, compared to women negative for chlamydia and gonorrhea, the relative risk (adjusted incidence rate ratio) of PID was 4.29 (95% confidence interval [CI], 3.66–5.03) in women who were both chlamydia and gonorrhea positive; 4.54 (95% CI, 3.87–5.33) in those only gonorrhea positive; and 1.77 (95% CI, 1.61–1.94) in those only chlamydia positive. Conclusions: Gonorrhea infection conferred a substantially higher risk than chlamydia of hospitalization or emergency department presentation for PID. The emergence of gonorrhea antimicrobial resistance may have a serious impact on rates of PID and its associated reproductive health sequelae