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.

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.

Invasive infections due to filamentous fungi other than Aspergillus: epidemiology and determinants of mortality

The epidemiology of invasive fungal disease (IFD) due to filamentous fungi other than Aspergillus may be changing. We analysed clinical, microbiological and outcome data in Australian patients to determine the predisposing factors and identify determinants of mortality. Proven and probable non-Aspergillus mould infections (defined according to modified European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria) from 2004 to 2012 were evaluated in a multicentre study. Variables associated with infection and mortality were determined. Of 162 episodes of non-Aspergillus IFD, 145 (89.5%) were proven infections and 17 (10.5%) were probable infections. The pathogens included 29 fungal species/species complexes; mucormycetes (45.7%) and Scedosporium species (33.3%) were most common. The commonest comorbidities were haematological malignancies (HMs) (46.3%) diabetes mellitus (23.5%), and chronic pulmonary disease (16%); antecedent trauma was present in 21% of cases. Twenty-five (15.4%) patients had no immunocompromised status or comorbidity, and were more likely to have acquired infection following major trauma (p <0.01); 61 (37.7%) of cases affected patients without HMs or transplantation. Antifungal therapy was administered to 93.2% of patients (median 68 days, interquartile range 19-275), and adjunctive surgery was performed in 58.6%. The all-cause 90-day mortality was 44.4%; HMs and intensive-care admission were the strongest predictors of death (both p <0.001). Survival varied by fungal group, with the risk of death being significantly lower in patients with dematiaceous mould infections than in patients with other non-Aspergillus mould infections. Non-Aspergillus IFD affected diverse patient groups, including non-immunocompromised hosts and those outside traditional risk groups; therefore, definitions of IFD in these patients are required. Given the high mortality, increased recognition of infections and accurate identification of the causative agent are required.

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 epidemiology of giardiasis in New Zealand, 1997-2006

Aims New Zealand has a higher incidence rate of giardiasis than other developed countries. This study aimed to describe the epidemiology of this disease in detail and to identify potential risk factors.

Methods We analysed anonymous giardiasis notification (1997–2006) and hospitalisation data (1990–2006). Cases were designated as urban or rural and assigned a deprivation level based on their home address. Association between disease rates and animal density was studied using a simple linear regression model, at the territorial authority (TA) level.

Results Over the 10-year period 1997–2006 the average annual rate of notified giardiasis was 44.1 cases per 100,000 population. The number of hospitalisations was equivalent to 1.7% of the notified cases. There were 2 reported fatalities. The annual incidence of notified cases declined over this period whereas hospitalisations remained fairly constant. Giardiasis showed little seasonality. The highest rates were among children 0–9 years old, those 30–39 years old, Europeans, and those living in low deprivation areas. Notification rates were slightly higher in rural areas. The correlation between giardiasis and farm animal density was not significant at the TA level.

Conclusions The public health importance of giardiasis to New Zealand mainly comes from its relatively high rates in this country. The distribution of cases is consistent with largely anthroponotic (human) reservoirs, with a relatively small contribution from zoonotic sources in rural environments and a modest contribution from overseas travel. Prevention efforts could include continuing efforts to improve hand washing, nappy handling, and other hygiene measures and travel health advice relating to enteric infections.

A tale of two parasites : the comparative epidemiology of cryptosporidiosis and giardiasis

New Zealand has a higher reported incidence of cryptosporidiosis and giardiasis than most other developed countries. This study aimed to describe and compare the epidemiology of these infections in New Zealand, to better understand their impact on public health and to gain insight into their probable modes of transmission. We analysed cryptosporidiosis and giardiasis notification data for a 10-year period (1997–2006). Highest rates for both diseases were in Europeans, children aged 0–5 years, and those living in low-deprivation areas. Cryptosporidiosis distribution was consistent with mainly farm animal (zoonotic) reservoirs. There was a dose–response relationship with increasing grades of rurality, marked spring seasonality, and positive correlation with farm animal density. Giardiasis distribution was consistent with predominantly human (anthroponotic) reservoirs, with an important contribution from overseas travel. Further research should focus on methods to reduce transmission of Cryptosporidium in rural areas and on reducing anthroponotic transmission of Giardia.

Mucormycosis in Australia: contemporary epidemiology and outcomes

Mucormycosis is the second most common cause of invasive mould infection and causes disease in diverse hosts, including those who are immuno-competent. We conducted a multicentre retrospective study of proven and probable cases of mucormycosis diagnosed between 2004-2012 to determine the epidemiology and outcome determinants in Australia. Seventy-four cases were identified (63 proven, 11 probable). The majority (54.1%) were caused by Rhizopus spp. Patients who sustained trauma were more likely to have non-Rhizopus infections relative to patients without trauma (OR 9.0, p 0.001, 95% CI 2.1-42.8). Haematological malignancy (48.6%), chemotherapy (42.9%), corticosteroids (52.7%), diabetes mellitus (27%) and trauma (22.9%) were the most common co-morbidities or risk factors. Rheumatological/autoimmune disorders occurred in nine (12.1%) instances. Eight (10.8%) cases had no underlying co-morbidity and were more likely to have associated trauma (7/8; 87.5% versus 10/66; 15.2%; p <0.001). Disseminated infection was common (39.2%). Apophysomyces spp. and Saksenaea spp. caused infection in immuno-competent hosts, most frequently associated with trauma and affected sites other than lung and sinuses. The 180-day mortality was 56.7%. The strongest predictors of mortality were rheumatological/autoimmune disorder (OR = 24.0, p 0.038 95% CI 1.2-481.4), haematological malignancy (OR = 7.7, p 0.001, 95% CI 2.3-25.2) and admission to intensive care unit (OR = 4.2, p 0.02, 95% CI 1.3-13.8). Most deaths occurred within one month. Thereafter we observed divergence in survival between the haematological and non-haematological populations (p 0.006). The mortality of mucormycosis remains particularly high in the immuno-compromised host. Underlying rheumatological/autoimmune disorders are a previously under-appreciated risk for infection and poor outcome.

Guided reflection: transcending a routine approach in the management of sexually transmissible infections

This paper describes a distinctive approach to the sexually transmissible infections (STI) clinical consultation: 'the guided reflection approach'. The authors coined this term and identified the guided reflection approach through analysis of 22 in-depth interviews with practitioners who provide care for people with STI, and 34 people who had attended a healthcare facility in Australia for screening or treatment of an STI. A grounded theory method was used to collect and analyse this information. The data revealed when the STI consultation is conducted using the principles characterized by the guided reflection approach creates contexts for sexual empowerment that have the potential to effectively assist people to gain autonomy for safe sex. Routinely, most of the practitioners in this study were shown to direct the STI consultation towards risk behaviours and practices and prevention of transmission, with minimal intervention. However, this study shows that if clinical interaction is to make a difference to the patient's autonomy for sexual behaviour, two changes will be required. First, practitioners need to adopt the goal of assisting patients to attain levels of autonomy, and second, practitioners require education to assist them to develop the interactive skills needed to engage patients in dialogue and reflection about sexual behaviour.

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/.

Teaching research and epidemiology to undergraduate students in the health sciences

Objective: To identify and address particular challenges in the teaching of epidemiological concepts to undergraduate students in non-clinical health disciplines. Methods and Results: Relevant pedagogical literature was reviewed to identify a range of evidence-based teaching approaches. The authors also drew on their experience in curriculum development and teaching in this field to provide guidelines for teaching epidemiology in a way that is engaging to students and likely to promote deep, rather than surface, learning. Discussion of a range of practical strategies is included along with applied examples of teaching epidemiological content. Conclusions and Implications: Increasingly, there is a greater emphasis on improved learning outcomes in higher education. Graduates from non-clinical health courses are required to have a core understanding of epidemiology and teachers of epidemiology need to be able to access resources that are relevant and useful for these students. A theoretically grounded framework for effective teaching of epidemiological principles to non-clinical undergraduates is provided, together with a range of useful teaching resources (both paper and web-based). Implementation of the strategies discussed will help ensure graduates are able to appropriately apply epidemiological skills in their professional practice.

HIV, stigma, and rates of infections : a rumour without evidence

The modern concept of a social stigma comes from the work of American sociologist Erving Goffman, who described it as a response to a deeply discrediting attribute that devalues the person [1]. In the medical literature, stigma is almost inevitably written about in terms of adverse social sequelae of a disease—such as leprosy, tuberculosis, epilepsy, schizophrenia, or filariasis [2–6]—or a physical characteristic or functional loss, such as obesity, deafness, or paraplegia [7–9]. The consequences of stigma range from moderate opprobrium at one end of the spectrum to death [10].

The epidemiology of overweight and obesity among Australian children and adolescents, 1995-97

A study attempts to determine the population prevalence of overweight and obesity among Australian children and adolescents, based on measured body mass index (BMI) to determine if overweight and obesity are distributed differentially across the population of young Australians. Data from three independent surveys were analyzed and results indicate that the population prevalence and distribution of overweight, obesity and overweight/obesity combined were 79%-81%, 14%-16%, 5% and 19%-21% (boys) respectively, and 76%-79%, 16%-18%, 5%-6% and 21%-24% (girls). There were no consistent relationships between the prevalence of overweight/obesity and sex, age or SES. It is concluded that some 19%-23% of Australian children and adolescents are either overweight or obese. Only cultural background differential warrant a targeted health promotion response.