Screening for chlamydia trachomatis : barriers for homeless young people

Objective: The study explored homeless young people's knowledge and attitudes of Chlamydia trachomatis (Chlamydia) and its screening.

Design: Semi-structured interviews using focus groups.

Setting: An inner city clinic for homeless young people.

Subjects: Homeless young people aged 16-26 years.

Outcomes: Perceptions of Chlamydia and its screening.

Results: 19 males and 6 females aged 16-26 years participated. Content analysis confirmed a lack of knowledge, prior education and misinformation about Chlamydia and barriers to being screened. Ideas for informing young people about Chlamydia included advertising on billboards, in free newspapers, and improved school sex education programs.

Conclusions: Homeless young people have poor knowledge of Chlamydia and its screening and barriers to the screening process. Culturally-specific education and health promotion programs and services are needed.

CIDB: Chlamydia Interactive Database for cross-querying genomics, transcriptomics and proteomics data

Chlamydiae are important pathogens of humans, birds and a wide range of animals. They are a unique group of bacteria, characterized by their developmental cycle. Chlamydia has been difficult to study because of their obligate intracellular growth habit and lack of a genetic transformation system. However, the past 5 years has seen the full genome sequencing of seven strains of Chlamydia and a rapid expansion of genomic, transcriptomic (RT-PCR, microarray) and proteomic analysis of these pathogens. The Chlamydia Interactive Database (CIDB) described here is the first database of its type that holds genomic, RT-PCR, microarray and proteomics data sets that can be cross-queried by researchers for patterns in the data. Combining the data of many research groups into a single database and cross-querying from different perspectives should enhance our understanding of the complex cell biology of these pathogens. The database is available at: http://www3.it.deakin.edu.au:8080/CIDB/.

Screening pregnant women for chlamydia : what are the predictors of infection?

Objectives: To determine the risk factors associated with chlamydial infection in pregnancy and the sensitivity and specificity of these when used for selective screening.

Methods: A prospective, cross-sectional study of pregnant women aged 16–25 years attending four major public antenatal services across Melbourne, Australia. Between October 2006 and July 2007, women were approached consecutively and asked to complete a questionnaire and to provide a first-pass urine specimen for Chlamydia trachomatis testing using PCR.

Results: Of 1180 eligible women, 1087 were approached and 1044 (88%) consented to participate. Among the 987 women for whom a questionnaire and a definitive diagnostic assay were available, the prevalence of chlamydia was 3.2% (95% CI 1.8 to 5.9). In a multiple logistic regression model, more than one sexual partner in the past year (AOR 11.5; 95% CI 7.1 to 18.5) was associated with chlamydia infection. The use of any antibiotic within 3 months (AOR 0.2; 95% CI 0.1 to 0.6) was associated with a decreased risk of infection. Screening restricted to women who reported more than one sexual partner in the past year would have detected 44% of infections in women aged 16–25 years and would have required only 7% of women to be screened. The addition of those women aged 20 years and under would have required 27% of women to be screened and detection of 72% of infections.

Conclusions: Selective chlamydia screening of pregnant women based on risk factors can improve the yield from screening. However, the potential harm of missed infections among excluded women would need to be considered.

The implementation of chlamydia screening : a cross-sectional study in the South East of England

Background England's National Chlamydia Screening Programme (NCSP) provides opportunistic testing for under 25 year-olds in healthcare and non-healthcare settings. The authors aimed to explore relationships between coverage and positivity in relation to demographic characteristics or setting, in order to inform efficient and sustainable implementation of the NCSP.

Methods The authors analysed mapped NCSP testing data from the South East region of England between April 2006 and March 2007 inclusive to population characteristics. Coverage was estimated by sex, demographic characteristics and service characteristics, and variation in positivity by setting and population group.

Results Coverage in females was lower in the least deprived areas compared with the most deprived areas (OR 0.48; 95% CI 0.45 to 0.50). Testing rates were lower in 20–24-year-olds compared with 15–19-year-olds (OR 0.69; 95% CI 0.67 to 0.72 for females and OR 0.67; 95% CI 0.64 to 0.71 for males), but positivity was higher in older males.

Females were tested most often in healthcare services, which also identified the most positives. The greatest proportions of male tests were in university (27%) and military (19%) settings which only identified a total of 11% and 13% of total male positives respectively. More chlamydia-positive males were identified through healthcare services despite fewer numbers of tests.

Conclusions Testing of males focused on institutional settings where there is a low yield of positives, and limited capacity for expansion. By contrast, the testing of females, especially in urban environments, was mainly through established healthcare services. Future strategies should prioritise increasing male testing in healthcare settings.

Computer reminders for chlamydia screening in general practice : a randomized controlled trial

Background: Chlamydia notifications are increasing in Australia, and the use of a computer alert prompting general practitioners to test young women is a potential way to increase opportunistic chlamydia testing. The aim of this trial was to determine the effectiveness of a computer alert in general practice on chlamydia testing in young women.

Methods: In 2006, clinics (n = 68) in Melbourne, Australia were cluster randomized into 2 groups: the intervention group received a computerized alert advising the general practitioner to discuss chlamydia testing with their patient which popped up when the medical record of a 16- to 24-year-old woman was opened; the control group received no alert. The outcome was whether or not that patient received a chlamydia test at the level of a single consultation with an eligible patient. A mixed effects logistic regression model adjusting for clustering was used to assess the impact of the alert on the proportion of women tested for chlamydia during the trial period.

Results: Testing increased from 8.3% (95% confidence interval (CI): 6.8, 9.8) to 12.2% (95% CI: 9.1, 15.3) (P < 0.01) in the intervention group, and from 8.8% (95% CI: 6.8, 10.7) to 10.6% (95% CI: 8.5, 12.7) (P < 0.01) in the control group. Overall, the intervention group had a 27% (OR = 1.3; 95% CI: 1.1, 1.4) greater increase in testing.

Conclusion: The results of this study suggest that alerts alone may not be sufficient to get chlamydia testing levels up sufficiently high enough to have an impact on the burden of chlamydia in the population but that they could be included as part of a more complex intervention.

Improving chlamydia knowledge should lead to increased chlamydia testing among Australian general practitioners: a cross-sectional study of chlamydia testing uptake in general practice

Female general practitioners (GPs) have higher chlamydia testing rates than male GPs, yet it is unclear whether this is due to lack of knowledge among male GPs or because female GPs consult and test more female patients.

Chlamydia screening for pregnant women aged 16-25 years attending an antenatal service: a cost-effectiveness study

OBJECTIVE: Determine the cost-effectiveness of screening all pregnant women aged 16-25 years for chlamydia compared with selective screening or no screening. DESIGN: Cost effectiveness based on a decision model. SETTING: Antenatal clinics in Australia. SAMPLE: Pregnant women, aged 16-25 years. METHODS: Using clinical data from a previous study, and outcomes data from the literature, we modelled the short-term perinatal (12-month time horizon) incremental direct costs and outcomes from a government (as the primary third-party funder) perspective for chlamydia screening. Costs were derived from the Medicare Benefits Schedule, Pharmaceutical Benefits Scheme, and average cost-weights reported for hospitalisations classified according to the Australian refined diagnosis-related groups. MAIN OUTCOME MEASURES: Direct costs of screening and managing chlamydia complications, number of chlamydia cases detected and treated, and the incremental cost-effectiveness ratios were estimated and subjected to sensitivity analyses. RESULTS: Assuming a chlamydia prevalence rate of 3%, screening all antenatal women aged 16-25 years at their first antenatal visit compared with no screening was $34,931 per quality-adjusted life-years gained. Screening all women could result in cost savings when chlamydia prevalence was higher than 11%. The incremental cost-effectiveness ratios were most sensitive to the assumed prevalence of chlamydia, the probability of pelvic inflammatory disease, the utility weight of a positive chlamydia test and the cost of the chlamydia test and doctor's appointment. CONCLUSION: From an Australian government perspective, chlamydia screening of all women aged 16-25 years old during one antenatal visit was likely to be cost-effective compared with no screening or selective screening, especially with increasing chlamydia prevalence. TWEETABLE ABSTRACT: Chlamydia screening for all pregnant women aged 16-25 years during an antenatal visit is cost effective.

Identification, characterisation and expression analysis of natural killer receptor genes in chlamydia pecorum infected koalas (phascolarctos cinereus)

BACKGROUND: Koalas (Phascolarctos cinereus), an iconic Australian marsupial, are being heavily impacted by the spread of Chlamydia pecorum, an obligate intracellular bacterial pathogen. Koalas vary in their response to this pathogen, with some showing no symptoms, while others suffer severe symptoms leading to infertility, blindness or death. Little is known about the pathology of this disease and the immune response against it in this host. Studies have demonstrated that natural killer (NK) cells, key components of the innate immune system, are involved in the immune response to chlamydial infections in humans. These cells can directly lyse cells infected by intracellular pathogens and their ability to recognise these infected cells is mediated through NK receptors on their surface. These are encoded in two regions of the genome, the leukocyte receptor complex (LRC) and the natural killer complex (NKC). These two families evolve rapidly and different repertoires of genes, which have evolved by gene duplication, are seen in different species. METHODS: In this study we aimed to characterise genes belonging to the NK receptor clusters in the koala by searching available koala transcriptomes using a combination of search methods. We developed a qPCR assay to quantify relative expression of four genes, two encoded within the NK receptor cluster (CLEC1B, CLEC4E) and two known to play a role in NK response to Chalmydia in humans (NCR3, PRF1). RESULTS: We found that the NK receptor repertoire of the koala closely resembles that of the Tasmanian devil, with minimal genes in the NKC, but with lineage specific expansions in the LRC. Additional genes important for NK cell activity, NCR3 and PRF1, were also identified and characterised. In a preliminary study to investigate whether these genes are involved in the koala immune response to infection by its chlamydial pathogen, C. pecorum, we investigated the expression of four genes in koalas with active chlamydia infection, those with past infection and those without infection using qPCR. This analysis revealed that one of these four, CLEC4E, may be upregulated in response to chlamydia infection. CONCLUSION: We have characterised genes of the NKC and LRC in koalas and have discovered evidence that one of these genes may be upregulated in koalas with chlamydia, suggesting that these receptors may play a role in the immune response of koalas to chlamydia infection.

The Australian longitudinal study of health and relationships

Background

Ensuring the sexual and reproductive health of the population is essential for the wellbeing of a nation. At least three aspects of sexual and reproductive health are among the key policy issues for present Australian governments: maintaining and increasing the birth rate; reducing the abortion rate; and preventing and controlling Chlamydia infections.

The overall aim of the Australian Longitudinal Study of Health and Relationships is to document the natural history of the sexual and reproductive health of the Australian adult population.
Methods/design

A nationally representative sample of Australian adults 16–64 years of age was selected in a two-phase process in 2004–2005. Eligible households were identified through random digit dialling. We used separate sampling frames for men and women; where there was more than one eligible person in a household the participant was selected randomly. Participants completed a computer-assisted telephone interview that typically took approximately 25 minutes to complete. The response rate was 56%. A total of 8,656 people were interviewed, of whom 95% (8243) agreed to be contacted again 12 months later. Of those, approximately 82% have been re-contacted and re-interviewed in 2006–07 (Wave Two), with 99% of those agreeing to be contacted again for Wave Three.
Discussion

ALSHR represents a significant advance for research on the linked topics of sexual and reproductive health. Its strengths include the large sample size, the inclusion of men as well as women, and the wide age range of the participants.

Temporal variation in reproductive characteristics of an introduced and abundant island population of koalas

Reproductive characteristics of a wildlife population are typically sensitive to changes in environmental conditions and intrinsic factors. Knowledge of these relationships is critical for understanding population dynamics and effective long-term management of a population. We examined temporal variation in reproductive parameters of an abundant, genetically compromised, and high-density population of koalas (Phascolarctos cinereus) on Kangaroo Island, South Australia, over 3 breeding seasons spanning 9 years: November–May of 1997–1998, 2005–2006, and 2006–2007. Timing of the breeding season was consistent between years, but fecundity, sex ratio of young, and the percentage of independent females (those not accompanying a lactating female) , 6 kg varied. Fecundity was lower than in other island populations, suggesting that the quality and distribution of food resources or inbreeding may be impacting the Kangaroo Island population. We did not test for Chlamydophila (synonym =Chlamydia), and clinical signs of this disease were not reported for any of the koalas in this study. However, historical evidence of Chlamydophila-infected koalas on Kangaroo Island exists, and the potential impact of this disease on fecundity warrants further investigation.