Biomedical subjects
Dan Ewald
Publications and source records attributed to Dan Ewald.
Strongyloidiasis: a review of the evidence for Australian practitioners.
OBJECTIVE: To summarise the available evidence concerning the prevalence, clinical manifestations, diagnosis and management of strongyloidiasis in Northern Australia. METHODS: We searched Medline, Clinical Evidence and the Cochrane Library using MeSH terms and text words 'strongyloides OR strongyloidiasis'. For Australian studies we included text words '(parasite* OR parasitic OR helminth*) AND Australia*'. We examined references contained in retrieved studies or identified from direct contact with researchers. Studies consistent with our objective that described their methods were eligible for inclusion. RESULTS: The prevalence in some tropical Aboriginal communities is high. Infection can be asymptomatic, cause a range of clinical syndromes or death. It may become chronic. Infected patients are at risk of developing severe disseminated disease particularly with immune compromise. There is little information about the relative frequency of different clinical outcomes. Available diagnostic tools are imperfect. Stool examination has a low sensitivity. Serology may have a low specificity in high prevalence populations and has not been evaluated in Aboriginal populations. Antihelmintic drugs are relatively safe and effective. Community programs based on treatment of stool-positive cases have been associated with a reduced prevalence of strongyloidiasis. We found no studies examining alternative public health interventions. CONCLUSION: There is a high prevalence in many Aboriginal communities. Strongyloides infection should be excluded prior to commencing immunosuppressive therapies in patients from endemic areas. Further studies examining the public health impact of strongyloidiasis, the role of the enzyme-linked immuno-sorbent assay serological test and population-based approaches to management of the disease in endemically infected Australian populations are needed.
Prevalence of cicatricial trachoma in an indigenous population of Central Australia: the Central Australian Trachomatous Trichiasis Study (CATTS).
BACKGROUND: Trachoma is one of the leading causes of blindness worldwide, resulting from conjunctival scarring, upper lid entropion and trichiasis, leading to corneal scarring and opacification. This study was designed to investigate the current prevalence of cicatricial trachoma in an indigenous population within Central Australia and help determine whether trachoma remains a public health issue. METHODS: Participants aged 40 and over were recruited from patients attending one of 16 remote ophthalmology clinics held at indigenous communities in Central Australia within the Northern Territory. Once informed consent had been obtained, each patient underwent examination for evidence of trachomatous scarring, trachomatous trichiasis and corneal opacities. Results were collated and compared with previous prevalence surveys. RESULTS: Among the sample (n = 181), there were 97 patients (54%; 95% CI 46.7-61.3) with trachomatous scarring, 15 patients (8%; 95% CI 2.8-13.2) with trichiasis and 5 patients (3%; 95% CI 0.5-5.5) with corneal opacities. CONCLUSION: This study suggests that, although the prevalence of the cicatricial and blinding consequences of trachoma may be decreasing in patients aged 40 years or greater, when compared with the current prevalence in other areas of Australia, trachoma still remains a public health issue in Central Australia.
Congenital heart defects in Central Australia.
OBJECTIVE: To determine the incidence of congenital heart defects (CHD) in Aboriginal and non-Aboriginal infants in Central Australia and to compare this with the incidence elsewhere in Australia. DESIGN AND SETTING: Data on cases were obtained from patient records of the Alice Springs Hospital, Central Australia, the sole referral centre for paediatric and initial cardiac diagnostic services for the region. PARTICIPANTS: Patients with CHD proven by echocardiography reported between 1 January 1993 and 30 June 2000. MAIN OUTCOME MEASURES: Incidence of CHD using all live births in Central Australia as the denominator. RESULTS: 108 patients with CHD were detected among 6156 live births (incidence, 17.5 per 1000; 95% CI, 14.9-21.7 per 1000); 57 of 2991 were Aboriginal (19.0 per 1000; 95% CI, 14.4-24.6 per 1000) and 51 of 3165 were non-Aboriginal (16.1 per 1000; 95% CI, 12.0-21.1 per 1000). The difference between the two groups was not statistically significant (relative risk, 1.18; 95% CI, 0.81-1.72). CHD incidence in Central Australia was significantly higher than that reported for other parts of Australia (4.3 per 1000 live births in New South Wales and the Australian Capital Territory, 1981-1984; 7.65 and 12 per 1000 total births in Western Australia, 1980-1989, and South Australia, 1993-2000, respectively). CONCLUSIONS: The high rates of CHD in Central Australia may partly reflect the high utilisation of echocardiography for assessing minor lesions. However, the incidence of both major and minor types of CHD was significantly higher than previously reported from other regions of Australia. The role of socioenvironmental factors in this high incidence should be explored.