Hypertension is associated with narrower retinal arteriolar calibre in persons with and without coronary artery disease.

The aims of this study were to investigate independent associations between hypertension and retinal vessel calibre in a high cardiovascular risk cohort and to determine whether these associations also exist in patients without coronary artery disease (CAD). The Australian Heart Eye Study is an observational study that surveyed 1680 participants presenting to a tertiary referral hospital for the evaluation of potential CAD by coronary angiography. Hypertension was defined as systolic >140 mm Hg, diastolic >90 mm Hg or treated (use of antihypertensive medications). Retinal arteriolar and venular calibres were measured from retinal photographs. CAD was quantified using severity (Gensini) and extent scores. Subanalyses were performed for people with and without CAD and for men and women. A total of 1114 participants had complete data on hypertension, coronary vessel evaluation and retinal vessel measurements and were included in cross-sectional analyses. Among persons with CAD, those with hypertension (compared with without) had narrower retinal arteriolar calibre (mean arteriolar calibre difference 2.1 µm, P=0.02), adjusting for age, sex, ethnicity, body mass index, smoking status and fellow vessel calibre. This association was also present among persons without CAD (mean difference 5.0 µm, P=0.04). Stratification by sex indicated that women with hypertension had marginally narrower retinal arterioles compared with normotensive women (multivariable-adjusted P=0.04). No significant association between hypertension and retinal arteriolar calibre was observed in men (P=0.13). No significant differences in retinal venular calibre were observed (P>0.05). In conclusion, in both subjects with and without CAD, hypertension was independently associated with narrower retinal arterioles.

Heterogeneity in the spatial distribution of bacterial sexually transmitted infections.

OBJECTIVES: Detailed knowledge of the spatial distribution of disease is required to inform service delivery and plan effective interventions. In order to elucidate the spatial epidemiology of three common sexually transmitted infections (STI) further, any significant spatiotemporal clustering of gonorrhoea, chlamydia or syphilis cases in New South Wales (NSW) was detected and described. METHODS: Eleven years of notified STI case data were analysed. Calculation of age and sex-stratified incidence rates was followed by spatiotemporal cluster analyses to investigate differences in the epidemiology of gonorrhoea, chlamydia and syphilis. RESULTS: More than one-third of all gonorrhoea, chlamydia and syphilis cases in NSW were detected within cluster areas. Gonorrhoea cases were the most highly clustered, followed by syphilis, then chlamydia. Clusters were highly significant and relative risk estimates ranged from 1.6 to 22.9. CONCLUSION: The findings establish the high degree of geographical heterogeneity in STI incidence in NSW and indicate that the postal area of residence is an important predictor of STI incidence. Geographical surveillance could be incorporated into routine STI surveillance to identify populations in need of intervention. The evidence presented in this report indicates a need to implement geography-specific and phase-appropriate STI prevention and control strategies.

Joining the DOTS in Bali: private practitioners' perceptions of tuberculosis control.

SETTING: The Indonesian island of Bali has both a national public tuberculosis (TB) programme and a significant private sector that provides treatment for patients with TB. OBJECTIVE: To explore private practitioners' perceptions of barriers to the treatment of patients with TB in Bali to inform strategies for future programme development. DESIGN: Semi-structured interviews were conducted with private practitioners who treated TB patients in their private practice. RESULTS: The main barriers to improved TB control in Bali identified by private practitioners reflect difficulties encountered within the following four areas: patient nonadherence to treatment, limitations of public services, public-private integration and limitations of private services. Private practitioners identified the need for improvements in the level of community education regarding TB, the degree of public-private interaction, the quality of diagnostic services and practitioner access to training. CONCLUSION: This study identified both strengths and weaknesses for TB control in the private sector, as well as considerable variations in perceptions and practice among private practitioners. The development of strategies to address these difficulties and utilise the inherent strengths of both public and private practitioners will be essential for improved service provision and TB control in Bali.

Does smoking explain sex differences in the global tuberculosis epidemic?

To date there has been no satisfactory explanation of the worldwide excess of tuberculosis (TB) notifications among adult males. We investigated the epidemiological basis for sex differences in TB notifications in high-burden countries using available group-level data. Multiple linear regression analysis was used to explore the ecological relationship between smoking and sex differences in TB notifications among high-burden countries. Cigarette consumption was a significant predictor of the sex ratio of TB notifications, and explained 33% of the variance in the sex ratio of TB notifications. Our findings suggest that smoking is an important modifiable factor which has a significant impact on the global epidemiology of TB, and emphasize the importance of tobacco control in countries with a high incidence of TB. This analysis provides support for the interpretation of sex differences in worldwide TB notification rates as indicative of true differences in the epidemiology of TB between males and females.

The association between subjective and clinical indicators of health in prospective Vietnamese migrants.

We conducted a cross-sectional survey of 1669 prospective Vietnamese migrants who had applied to migrate to Australia to describe the association between self-reported health status and several commonly used clinical indicators of health among prospective Vietnamese migrants. Participants were recruited from the International Organization for Migration's standardised medical screening program.' We found that clinical indicators of health are related to self-reported health status among prospective Vietnamese migrants. Self-reported health status, which was assessed using a modified version of the Short Form-36 health survey, was significantly associated with clinical indicators of health, including the number of body system abnormalities identified during medical screening, evidence of tuberculosis on chest radiograph, and self-reported weight loss over the previous six months. These findings support the validity of self-reported health status assessment among prospective migrants, although the assessment of subjective indicators of health during compulsory medical screening may be limited by reporting bias.

Results of tuberculosis screening in applicants for migration in Vietnam and Cambodia.

SETTING: Pre-migration medical screening programmes in Ho Chi Minh City, Vietnam and Phnom Penh, Cambodia. OBJECTIVE: To compare the rates of newly diagnosed bacteriologically confirmed tuberculosis (TB) in a cohort of migration applicants in Vietnam and Cambodia with current estimates of the TB burden in these countries. DESIGN: Interviews and medical screening of 5108 Vietnamese and 910 Cambodian migration applicants who applied for an Australian visa. RESULTS: On initial testing, the rate of bacteriologically confirmed TB among the Vietnamese cohort was 157 per 100,000 population compared to 989/100,000 among the Cambodian cohort. When cases detected during follow-up testing were included, the rate in the Vietnamese cohort was 489/100,000 compared to 1209/100,000 in the Cambodian cohort. CONCLUSIONS: Although it has been suggested that the rate of newly diagnosed bacteriologically confirmed TB among migration applicants would underestimate the prevalence of TB in the Vietnamese and Cambodian populations, the rates found were substantially higher than current point estimates of the prevalence of TB, particularly for Vietnam. Our findings suggest that current published estimates of the tuberculosis burden in Vietnam and Cambodia may be conservative.

Clinic staff perceptions of tuberculosis treatment delivery in Bali.

A number of studies have investigated patient perceptions of tuberculosis (TB) treatment delivery, but few have systematically investigated the perceptions of clinic staff. We therefore conducted individual interviews using Q-methodology with 25 staff directly involved in the delivery of TB treatment services in 18 different public sector health centres in Bali. Factor analysis was used to identify shared perceptions of TB treatment delivery in Bali among the sample studied. Three distinct perspectives emerged, indicating that all staff do not have shared understandings of difficulties and priorities in TB treatment. The main areas of difference in staff perceptions concerned the existence of barriers to treatment and the focus on the community context of TB treatment. The demonstrated variation in the perceptions of TB treatment delivery in Bali has important implications for the design of strategies to improve treatment delivery and the control of TB.

A syphilis outbreak in remote Australia: epidemiology and strategies for control.

This paper describes the epidemiology of a syphilis outbreak in remote Australia, and explores contributing factors and control strategies. Between 1 August 2000 and 31 January 2002, 74 cases of early syphilis (42 female, 32 male) were identified in 73 Kimberley residents. Syphilis rates in age groups 10-19 and 20-29 years were 583 and 439 per 100000 person years respectively. Factors contributing to the outbreak included incompleteness of sexually transmitted infection (STI) clinical management, untimely contact tracing, staffing and management issues, and poor community knowledge about STIs. Outbreak control strategies addressed factors that could be influenced by changes in health service delivery, and focused on providing education and support to health staff, and efforts to increase community knowledge about sexual health. Although some improvements have occurred, the outbreak is still continuing. Until open and honest discussion and a collaborative approach is taken toward STI problems affecting Indigenous Australians, outbreaks such as this will continue to occur.

Tuberculosis treatment delivery in Bali: a qualitative study of clinic staff perceptions.

SETTING: Little is known about the challenges of delivering tuberculosis (TB) treatment in Indonesia's southern province of Bali. OBJECTIVE: We aimed to explore staff perceptions of TB treatment delivery and barriers to improved TB control in Bali to inform strategies for programme development. DESIGN: Semi-structured interviews were conducted with staff who were involved in the delivery of TB treatment services in the public sector. RESULTS: The main issues perceived by staff to influence TB treatment delivery include: the low level of community awareness of TB; delays to treatment seeking and the frequent use of private treatment providers; diagnostic difficulties; non-adherence to treatment; and a low level of staff education specific to TB. CONCLUSION: Staff perceived a number of significant barriers to the early diagnosis and successful treatment of TB in Bali. The development of strategies to address these identified difficulties in TB control is essential to support improved programme effectiveness and enhanced TB control in Bali.

Tuberculosis rates among migrants in Australia and Canada.

Multiple linear regression analysis was used to compare the regression coefficients for Australia and Canada on the association between tuberculosis (TB) rates among migrants and the estimated incidence in the country of birth. Regression coefficients predicting the rate of TB among migrants based on the incidence of TB in the country of birth are not significantly different between populations of migrants in Australia and Canada. Our findings support the ability of the incidence of TB in the country of birth to predict variation in the incidence of TB in migrants groups in two migration receiving countries. This information can be used to focus TB treatment and prevention efforts towards high-risk groups.

Predictors of tuberculin reactivity among prospective Vietnamese migrants: the effect of smoking.

We investigated the prevalence and predictors of positive tuberculin skin test (TST) results among prospective Vietnamese migrants. We interviewed and medically screened 1395 Vietnamese people aged over 15 years who had applied to migrate to Australia. Approximately 44% of applicants had an induration of 10 mm or more, and 18.6% had an induration of 15 mm or more. A positive tuberculin skin test at 5 mm, 10 mm and 15 mm of induration cut-points was significantly associated with age (OR 1.01-1.02 per year) and duration of smoking (OR 1.03-1.12 per year). Smoking appears to be an important factor associated with increased susceptibility to mycobacterial infection. It is not yet clear whether the increased tuberculin reactivity associated with smoking reflects an increased risk of tuberculosis among these migrants.

Predicting tuberculosis among migrant groups.

In industrialized countries migrants remain a high-risk group for tuberculosis (TB). Multiple linear regression analysis was used to determine the ability of indicators of TB incidence in the country of birth to predict the incidence of TB among migrants in Australia during 1997. World Health Organization total case notifications, new smear-positive case notifications and the estimated incidence of TB by country of birth explained 55, 69 and 87% of the variance in TB incidence in Australia, respectively. Gross national income of the country of birth and unemployment level in Australia were also significant predictors of TB in migrant groups. Indicators of the incidence of TB in the country of birth are the most important group-level predictors of the rate of TB among migrants in Australia.

John Flynn Scholarship students: case studies of useful contributions to remote health care.

In 1997, the John Flynn Scholarship (JFS) program was launched as an initiative to increase recruitment of doctors to rural areas. These scholarships enable undergraduate medical students to spend 2 weeks each year for 4 years at the same rural location. Given the magnitude of Australia's unmet rural health needs, we asked whether the experience could be enhanced by ensuring the students undertook meaningful work that was useful for the community. This paper describes, using case studies, some of the activities in which four JFS students have been involved and the positive contributions that they have made to rural health. The case studies indicate that pre-clinical students can be valuable members of the rural health workforce. We hope that if JFS students are given the opportunity to work as responsible health professionals they will have a better learning experience and will be more likely to return to the bush as doctors.

Where the data are deficient: a field evaluation of the effectiveness of pneumococcal vaccination in remote Australia.

The aims of the study were to: (i) determine whether a field evaluation of a pneumococcal vaccination program conducted in 1991-1993 could show whether the program was effective; and (ii) to describe the epidemiology of invasive pneumococcal disease using laboratory surveillance data. As part of quality assurance, we undertook a retrospective cohort study to compare the hospitalisation and mortality rates of a pneumococcal-vaccine-vaccinated and an unvaccinated group and a correlational study to compare the before- and after-vaccination hospitalisation rates for the vaccinated and unvaccinated groups. We used laboratory data to describe the epidemiology of invasive pneumococcal disease. The cohort study consisted of 815 subjects (306 vaccinated, 509 comparison). No significant differences were observed in the admission rates for pneumonia and lower respiratory tract infection between the two groups. By using a correlational study, we examined before- and after-vaccination hospitalisation rates and this also failed to reveal any differences, except for persons aged 50 years and older. Laboratory surveillance of invasive disease demonstrated that children younger than 6 years and adults younger than 50 years with alcohol-related problems accounted for most of the cases. Despite the study's limitations, it supports the use of pneumococcal vaccine in persons aged older than 50 years, while at the same time highlighting the ongoing need for better vaccines, especially for children and those aged younger than 50 years with medical conditions predisposing to pneumococcal disease.

A large outbreak of conjunctivitis caused by a single genotype of Neisseria gonorrhoeae distinct from those causing genital tract infections.

Several epidemics of gonococcal conjunctivitis have occurred in Aboriginal populations in Central Australia. In 1997, the first outbreak in the Kimberley region of Western Australia occurred, spreading to Central Australia with a total of 447 cases. A genotyping method was applied directly to DNA extracted from patient samples to characterize the gonococcus causing the epidemic and to compare it with contemporaneous genital isolates. Those positive conjunctival specimens from Kimberley and Central Australia that could be genotyped were all indistinguishable, but were distinct from the genital gonococci, even when they shared the same auxotype and serotype. This suggested that the outbreak was due to a single genotype of Neisseria gonorrhoeae that had probably been carried between communities by infected individuals. We did not find evidence to support the existence of a genital reservoir of the types causing epidemic gonococcal conjunctivitis.

Shifting the balance between in-patient and out-patient care for tuberculosis results in economic savings.

SETTING: Although hospitalisation is not always necessary for the treatment of tuberculosis (TB), in Australia 90% of TB patients have treatment initiated in hospital. OBJECTIVE: To calculate and compare the costs of in-patient and out-patient tuberculosis treatment, and to measure the impact of shifting care from in-patient to out-patient settings. METHODS: In a costing study performed in Victoria, Australia, the proportion of all notified TB cases who were hospitalised was calculated by matching coded state hospital morbidity data with the Victoria Notifiable Diseases database for the financial year 1994-1995. In-patient and out-patient costs were calculated using data obtained from a number of sources. The effect on health care costs of varying the proportion of TB cases treated as in-patients and out-patients was calculated using Excel. RESULTS: Nearly 90% (239/269) of notified TB cases received hospitalised care in 1994-1995. The cost of treatment for hospitalised patients (mean length of stay 2 weeks) was AU$5447 per patient, with a total cost of $1,301,833. Hospitalisation comprised 60% of the total cost of treatment. The cost of out-patient treatment was $2260 per patient. If 90% of patients were treated on an out-patient basis, the total cost would be $693,670. We estimated that it would be feasible to treat at least 55% of TB patients as out-patients, reducing costs by nearly 30%. CONCLUSIONS: Routine hospitalisation for patients with uncomplicated TB is not necessary, but is often used in industrialised countries. More cost-effective use of resources can be achieved by giving initial TB treatment on an out-patient basis rather than in hospital for a greater proportion of cases.

A randomized trial of a problem-based learning approach for teaching epidemiology.

PURPOSE: To conduct a controlled trial of traditional and problem-based learning (PBL) methods of teaching epidemiology. METHOD: All second-year medical students (n = 136) at The University of Western Australia Medical School were offered the chance to participate in a randomized controlled trial of teaching methods for an epidemiology course. Students who consented to participate (n = 80) were randomly assigned to either a PBL or a traditional course. Students who did not consent or did not return the consent form (n = 56) were assigned to the traditional course. Students in both streams took identical quizzes and exams. These scores, a collection of semi-quantitative feedback from all students, and a qualitative analysis of interviews with a convenience sample of six students from each stream were compared. RESULTS: There was no significant difference in performances on quizzes or exams between PBL and traditional students. Students using PBL reported a stronger grasp of epidemiologic principles, enjoyed working with a group, and, at the end of the course, were more enthusiastic about epidemiology and its professional relevance to them than were students in the traditional course. PBL students worked more steadily during the semester but spent only marginally more time on the epidemiology course overall. Interviews corroborated these findings. Non-consenting students were older (p < 0.02) and more likely to come from non-English-speaking backgrounds (p < 0.005). CONCLUSIONS: PBL provides an academically equivalent but personally far richer learning experience. The adoption of PBL approaches to medical education makes it important to study whether PBL presents particular challenges for students whose first language is not the language of instruction.

Trichiasis in Aboriginal people of the Kimberley region of Western Australia.

BACKGROUND: Trachoma is a significant public health problem in the Kimberley region of Western Australia. The prevalence of follicular trachoma in the region has been well documented and control of active trachoma is well established. In contrast, trichiasis prevalence in recent years is less well documented. This study aimed to determine trichiasis prevalence in the Kimberley population and to document an appropriate intervention. METHODS: A collaborative programme was established involving the Kimberley Public Health Unit, Kimberley Aged Care Services and the visiting ophthalmology service. After training, medical students screened the aged-care population for trichiasis and the aged-care services staff were educated about identification and referral procedures for patients with trichiasis. The Kimberley Public Health Unit was responsible for ensuring specialist assessment, and correction, of trichiasis and appropriate post-treatment follow up. RESULTS: A total of 597 Kimberley Aboriginal people aged 50 years or more were screened for trichiasis, representing 42% of that age group. Trichiasis was suspected in 40 people. Of the 28 people with suspected trichiasis who underwent ophthalmological assessment, 17 were found to have trachomatous trichiasis. The observed prevalence of trachomatous trichiasis was 2.8%. The trichiasis screening programme has been adopted by most aged-care organizations in the Kimberley. CONCLUSIONS: The results show that trichiasis continues to affect elderly Aboriginal people, especially those from Halls Creek Shire. Health professionals and aged-care workers should be alert to the possibility of this preventable cause of blindness and work collaboratively to ensure that patients receive timely and appropriate treatment.