Natural history of dental caries in very young Australian children.

BACKGROUND: Whilst the global burden of caries is increasing, the trajectory of decay in young children and the point at which prevention should occur has not been well established. AIM: To identify the 'natural history' of dental caries in early childhood. DESIGN: A birth cohort study was established with 467 mother/child dyads followed at 1, 6, 12, 18, and 36 months of age. Parent-completed surveys captured demographic, social, and behavioural data, and oral examinations provided clinical and data. RESULTS: Eight per cent of children (95% confidence interval (CI): 5-12%) at 18 months and 23% (95% CI: 18-28%) at 36 months experienced decay. Interesting lesion behaviour was found between 18 and 36 months, with rapid development of new lesions on sound teeth (70% of teeth, 95% CI: 63-76%) and regression of many lesions from non-cavitated lesions to sound (23% of teeth, 95% CI: 17-30%). Significant associations were found between soft drink consumption and lesion progression. CONCLUSIONS: Findings suggest optimal time periods for screening and prevention of a disease which significantly impacts multiple health and well-being outcomes across the life course.

Low-level fluoroquinolone resistance among Campylobacter jejuni isolates in Australia.

BACKGROUND: Ciprofloxacin-resistant Campylobacter jejuni isolates obtained from infected patients in Australia have not been detected in studies of isolates from specific geographic areas. The Australian government has prohibited the use of fluoroquinolone in food-producing animals. To assess the impact of this policy, we have examined the antimicrobial susceptibility of isolates from 5 Australian states. METHODS: We conducted a period-prevalence survey of the susceptibility of C. jejuni isolates to 10 antimicrobial agents. C. jejuni isolates obtained from 585 patients from 5 Australian states (Queensland, South Australia, Tasmania, Victoria, and Western Australia) were identified by means of notifiable disease databases and were systematically selected from September 2001 to August 2002. RESULTS: Among locally acquired infections, only 2% of isolates (range, 0%-8% in different states) were resistant to ciprofloxacin. The locally acquired isolates also exhibited resistance to sulfisoxazole (55%), ampicillin (46%), roxithromycin (38%), tetracycline (7%), nalidixic acid (6%), chloramphenicol (3%), erythromycin (3%), gentamicin (2%), and kanamycin (0.2%). Treatment with antimicrobial agents in the 4 weeks before onset was not associated with ciprofloxacin resistance. CONCLUSIONS: The very low level of ciprofloxacin resistance in C. jejuni isolates likely reflects the success of Australia's policy of restricting use of fluoroquinolones in food-producing animals.

Parental self-efficacy and oral health-related knowledge are associated with parent and child oral health behaviors and self-reported oral health status.

OBJECTIVES: This study sought to advance understanding of the influence of psychosocial factors on oral health by examining how parental self-efficacy (with regard to acting on their child's oral health needs) and oral health knowledge relate to parental and child oral health behaviors and self-rated oral health. METHODS: Parents of children in grades 0/1 and 5/6 (n = 804) and children in grades 5/6 (n = 377, mean age 11.5 ± 1.0, 53.9% female) were recruited from a stratified random sample of 11 primary (elementary) schools. Participants completed surveys capturing psychosocial factors, oral health-related knowledge, and parental attitudes about oral health. Parents also rated their own oral health status and the oral health of their child. Correlations and logistic regression analysis (adjusted for socioeconomic status, child age, and gender) examined associations between psychosocial factors and the outcomes of interest (parent and child behaviors and self-rated oral health status). RESULTS: Higher parental self-efficacy was associated with more frequent toothbrushing (by parent and child), and more frequent visits to a dental professional. These associations were particularly strong with regard to dental visits for children, with parents with the highest tertile for self-efficacy 4.3 times more likely to report that their child attended a dentist for a checkup at least once a year (95%CI 2.52-7.43); and 3 times more likely to report their child brushing their teeth at least twice a day (Adjusted Odds Ratio 3.04, 95%CI 1.64-5.64) compared with those parents in the lowest tertile for self-efficacy. No associations with oral health knowledge were found when examined by tertile of increasing knowledge. CONCLUSIONS: Oral health self-efficacy and knowledge are potentially modifiable risk factors of oral health outcomes, and these findings suggest that intervening on these factors could help foster positive dental health habits in families.

Increasing school playground physical activity: a mixed methods study combining environmental measures and children's perspectives.

Schools are integral settings in which children can participate in moderate and vigorous physical activity. This study reports on the relationship between playground characteristics and child activity levels using a combination of quantitative and qualitative methods. The aim of the study is to increase understanding of how children respond to their school playground environments. Twenty-three primary schools located in a predominantly low socio-economic area of Melbourne, Australia were involved. SOPLAY (System for Observing Play and Leisure Activity in Youth) was administered in all 23 schools to measure the levels of student physical activity and playground environmental factors such as equipment provision. In 12 of the 23 schools, a sample of 9-11-year-old students participated in focus group discussions exploring perceptions of their school playgrounds using a photo ordering technique. A larger proportion of students participated in VPA when loose equipment (60% vs. 52%; p<0.001) and teacher supervision (62% vs. 52%; p<0.001) were present in activity settings, compared to when they were unavailable. Fixed play equipment and bitumen with court/play-line markings were seen by children as settings inviting active play but only had the greatest impact on moderate activity (fixed play equipment: 35% vs. 20%, p<0.001; court markings/goals: 62% vs. 52%, p<0.001; play-line markings: 25% vs. 20%, p=0.04). The mixed method design provided a greater understanding of the potential influence of environmental characteristics on children's lunch time activity levels and their perceptions of play areas. The findings indicate that relatively simple changes such as the provision of loose equipment, painting of court and play-line markings, and increased teacher presence on the playground, are likely to provide opportunities for increased physical activity.

Double disadvantage: the influence of ethnicity over socioeconomic position on childhood overweight and obesity: findings from an inner urban population of primary school children.

OBJECTIVE: To examine the relationship between overweight/obesity in children, socioeconomic status and ethnicity/cultural background. DESIGN: Cross-sectional survey of children aged 4-13 years. SETTING: A total of 23 primary (elementary) schools in an inner urban municipality of Melbourne, Australia. Participants. A total of 2685 children aged 4-13 years and their parents. MAIN EXPOSURE MEASURES: Ethnicity/cultural background - maternal region of birth; socioeconomic position (SEP) indicators - maternal and paternal educational attainment, family employment status, possession of a healthcare card, ability to buy food, indicator of disadvantage (Socioeconomic Index for Areas, SEIFA) score for school; parental weight status. Main outcome measure. Prevalence of overweight/obesity. RESULTS: Prevalence of overweight/obesity approached 1 in 3 (31%) in this sample. Prevalence of overweight/obesity was greater for children of both North Africa and Middle Eastern background and children of Southern, South Eastern and Eastern European background compared with children of Australian background. This difference remained after adjusting for age, sex, height, clustering by school, SEP indicators and parental weight status; odds ratio, OR=1.57 (95% confidence interval, CI 1.12-2.19) and 1.88 (95%CI 1.24-2.85), respectively. CONCLUSIONS: There is a clear independent effect of ethnicity above and beyond the effect of socioeconomic status on overweight and obesity in children. Further research is required to explore the mediators of this gradient.

Quantifying the change of melanoma incidence by Breslow thickness.

Melanoma incidence has increased throughout the world over the past 25 years. A surrogate for the severity of melanoma is the Breslow thickness of the lesions. Data on melanoma, including Breslow thickness, were collected in 1978-1980 and 1988-1990 from the Tasmania Tumor Registry. We use a density ratio model to quantify the change of melanoma by Breslow thickness. In this model, the ratio of two densities is assumed to have a known form up to a parameter, but the underlying densities are not modeled. This model includes the length bias sampling model as a special case. The Kolmogorov-Smirnov test statistic is used to test the correctness of the density ratio model. Model-based cumulative distribution estimation is studied. Methodology developed in this article is applied to the Tasmania Tumor Registry data.

An outbreak of cryptosporidiosis associated with an animal nursery at a regional fair.

Cryptosporidiosis is a common gastrointestinal illness that is transmitted from infected persons, animals, or contaminated water or food. This article reports on an outbreak of cryptosporidiosis associated with an animal nursery at an agricultural show held in northern Tasmania during October 2001. Eighty-one per cent of cases (38/47) notified to the Tasmanian Department of Health and Human Services over a 35 day period were interviewed to determine potential sources of infection. Eighty-one per cent of interviewed cases (29/36) reported that they had attended the agricultural show, and 75 per cent (27/36) reported contact with animals in the animal nursery. Cases occurring more than one incubation period after the agricultural show were significantly more likely to have had contact with someone else with diarrhoea (p<0.01). This is the first reported outbreak of cryptosporidiosis associated with an animal nursery in Australia. The outbreak demonstrates the importance of infection control policies and hygiene measures in the animal nursery setting.

A multi-jurisdictional outbreak of hepatitis A related to a youth camp--implications for catering operations and mass gatherings.

In June 2003, Australian state and territory health departments were notified of an outbreak of Hepatitis A in people who had attended a five-day youth camp. Approximately 350 people attended the event in Central Australia between 24 and 28 April 2003. The public health investigation comprised of case identification, food handler interviews, an environmental health investigation of the campground and associated food premises, laboratory analysis of blood specimens and food/water samples, and an epidemiological study. Twenty-one cases fitted the case definition for the outbreak. A retrospective cohort study involving four states was conducted, with 213 people interviewed. Coleslaw and cordial were significantly associated with illness, however when the two exposures were adjusted for each other to account for confounding, only coleslaw remained significantly associated with illness (adjusted RR 2.5, 95% CI 1.09 - 5.77). The investigation highlighted a number of food hygiene and safety issues relating to the catering of mass gatherings. Implementation of food safety programs in these settings are likely to reduce the occurrence of such outbreaks. The recent proposal by Food Standards Australia New Zealand to mandate food safety programs for catering operations is supported.

Does the addition of information on genotype improve prediction of the risk of melanoma and nonmelanoma skin cancer beyond that obtained from skin phenotype?

The authors quantified improvement in predicting cutaneous malignant melanoma, basal cell carcinoma, and squamous cell carcinoma of the skin made possible by information on common variants of the melanocortin-1 receptor gene (MC1R) in a 1998-1999 population-based case-control study of subjects aged 20-59 years of northern European ancestry in Tasmania, Australia. Melanin density at the upper inner arm was estimated by spectrophotometry. DNA samples were genotyped for five MC1R variants: Val60Leu, Asp84Glu, Arg151Cys, Arg160Trp, and Asp294His. Among controls (n = 267), variant carriers, versus noncarriers, had lower (p < 0.01) mean melanin concentrations. Increased risk conferred by genotype was restricted mainly to those with the darkest skins: for subjects with at least 2% melanin, the odds of carrying each additional variant were higher for cutaneous malignant melanoma (n = 39; odds ratio = 1.45, 95% confidence interval: 0.87, 2.44), basal cell carcinoma (n = 35; odds ratio = 1.86, 95% confidence interval: 1.14, 3.02), and squamous cell carcinoma (n = 42; odds ratio = 2.67, 95% confidence interval: 1.50, 4.74) cases than for controls (n = 135). Adding MC1R information to prediction based on age, sex, and cutaneous melanin increased the area under the receiver operating characteristic curve by 1.4% (cutaneous malignant melanoma), 3.2% (basal cell carcinoma), or 2.0% (squamous cell carcinoma). The improvement in prediction was probably too small to be valuable in a clinical setting.

Enhancing foodborne disease surveillance across Australia in 2001: the OzFoodNet Working Group.

In 2000, the OzFoodNet network was established to enhance surveillance of foodborne diseases across Australia. OzFoodNet consists of 7 sites and covers 68 per cent of Australia's population. During 2001, sites reported 15,815 cases of campylobacteriosis, 6,607 cases of salmonellosis, 326 cases of shigellosis, 71 cases of yersiniosis, 61 cases of listeriosis, 47 cases of shiga-toxin producing E. coli and 5 cases of haemolytic uraemic syndrome. Sites reported 86 foodborne outbreaks affecting 1,768 people, of whom 4.0 per cent (70/1,768) were hospitalised and one person died. There was a wide range of foods implicated in these outbreaks and the most common agent was S. Typhimurium. Sites reported two international outbreaks; one of multi-drug resistant S. Typhimurium Definitive Type 104 due to helva imported from Turkey, and one of S. Stanley associated with dried peanuts from China. The National Centre for Epidemiology and Population Health conducted a national survey of gastroenteritis. Preliminary data from interviews of 2,417 people suggests that the incidence of foodborne illness is significantly higher than previously thought. OzFoodNet initiated case control studies into risk factors for Campylobacter, Salmonella, Listeria, and shiga-toxin producing E. coli. OzFoodNet developed a foodborne disease outbreak register for Australia; established a network of laboratories to type Campylobacter; prepared a survey of pathology laboratories; reviewed Australian data on listeriosis; and assessed the usefulness of sentinel surveillance for gastroenteritis. This program of enhanced surveillance has demonstrated its capacity to nationally investigate and determine the causes of foodborne disease.