Rennie M. D'Souza

Does ambient temperature affect foodborne disease

Background: Foodborne illness is a significant public health issue in most countries, including Australia. We examined the association between temperature and salmonellosis notifications, and compared these associations for 5 Australian cities. Methods: Log-linear models describing monthly salmonellosis notifications in terms of calendar time and monthly average temperatures were fitted over the period 1991 to 2001 for each city. We used a negative binomial chance model to accommodate overdispersion in the counts. Results: The long-term trend showed an increase in salmonellosis notifications in each of the 5 cities. There was a positive association between monthly salmonellosis notifications and mean monthly temperature of the previous month in every city. Seasonal patterns in salmonellosis notifications were fully explained by changes in temperature. Discussion: The strength of the association, the consistency across 5 cities, and a plausible biologic pathway suggest that higher ambient temperatures are a cause of higher salmonellosis notifications. The lag of 1 month suggests that temperature might be more influential earlier in the production process rather than at the food preparation stage. This knowledge can help to guide policy on food preparation and distribution. It also suggests a basis for an early warning system for increased risk from salmonellosis, and raises yet another possible health problem with global warming.

Work and health in a contemporary society: demands, control, and insecurity

Objective: To examine independent associations of job strain (high demands and low control) and job insecurity with mental and physical health outcomes. Design: Cross sectional general population study conducted in 2000 using a self completed questionnaire. Setting: Two adjoining cities in south east Australia. Subjects: 1188 employed professionals, aged 40–44 years, 55% (n = 655) male. Main outcome measures: Depression, anxiety, physical, and self rated health (SRH). Results: Adverse job conditions were relatively prevalent as 23% of the sample reported high job strain, while 7.3% and 23% reported high and moderate job insecurity respectively. Associations between job conditions and health persisted after adjustment for gender, education, marital status, employment status, major life events, and negative affectivity (personality). When adjusted for job strain, high job insecurity was independently associated with a greater than threefold increase in odds for poor SRH, depression and anxiety (OR (95% confidence intervals) poor SRH: 3.72 (1.97 to 7.04) depression: 3.49 (1.90 to 6.41), anxiety: 3.29 (1.71 to 6.33)), and a twofold increase for physical health 2.19 (1.21 to 3.95). High job strain also showed significant independent associations with depression: 2.54 (1.34 to.4.75) and anxiety: 3.15 (1.48 to 6.70). Conclusion: In this relatively privileged socioeconomic group, insecure employment and high job strain showed independent, consistent, and strong associations with physical and mental health. These adverse job conditions are on the increase, particularly insecure employment, and the influence of these two work conditions are an important focus for future public health research and their prevalence and impact should be examined in other occupations.

Job Strain, Job Insecurity, and Health: Rethinking the Relationship

Job strain (high demands and low control) is a widely used measure of work stress. The authors introduce a new way of looking at work stress by combining job strain with job insecurity, a combination increasingly prevalent in contemporary economies, using data from a cross-sectional survey (N = 1,188) of mid-aged Australian managers and professionals. Those reporting both strain and insecurity showed markedly higher odds for mental and physical health problems (depression: odds ratio [OR] 13.88, 95% confidence interval [CI] 5.67-34.01; anxiety: OR 12.88, CI 5.12-32.39; physical health problems: OR 3.97, CI 1.72-9.16; and poor self-rated health: OR 7.12, CI 2.81-18.01). Job strain and insecurity showed synergistic associations with health, and employees experiencing both could be at heightened health risk.

Climatic factors associated with hospitalizations for rotavirus diarrhoea in children under 5 years of age

This study compares the seasonality of rotavirus diarrhoeal hospital admissions and its relationship to climatic factors across three Australian cities. Weekly admission of rotavirus diarrhoea (1993-2003) in children aged <5 years and weekly average temperature and relative humidity for each city were modelled using a log-linear model with a cubic trend and season. Interactions were included to test for differences in the effect of temperature and humidity between seasons and between cities. Admissions of rotavirus diarrhoea peaked in winter and spring and were lowest in summer. Higher temperature and humidity in the previous week were associated with a decrease in rotavirus diarrhoeal admissions in three cities. The effects of both temperature and humidity on rotavirus admissions in Brisbane differed across seasons. Strategies to combat outbreaks of rotavirus diarrhoea should take climatic factors and seasonal effects into consideration to plan for the excess seasonal hospital admissions.

The associations between work stress and mental health: A comparison of organizationally employed and self-employed workers

This study examined the associations between work stressors and mental health in organizationally employed and self-employed workers, and with the numbers of general practitioner (GP) services used by these two employment groups. The participants were selected from those already taking part in the PATH Through Life Project, in Australia. A total of 2275 men and women aged from 40 to 44 years participated in a community survey and were in the labour force at the time of the interview. Those who participated entered responses into a hand-held computer under the supervision of an interviewer. A total of 14.2% of the group identified themselves as self-employed. Respondents also provided details of their occupation and the extent to which they experienced work stressors. Some 72.6% of these participants gave consent for information on their use of GP services over a 12-month period to be obtained from national insurance records. We found that self-employed men and women reported more decision authority than the organizationally employed, while self-employed women also had more manageable job demands. Self-employment offered men no health benefit. However, women who were self-employed reported worse physical health than their organizationally employed counterparts. While work stress factors were most likely to be associated with the use of GP services by self-employed men, the use of those services by women was more strongly associated with their experiences of stress in organizational employment. Overall, self-employment was found to be associated with relatively few mental health benefits.

ROLE OF HEALTH-SEEKING BEHAVIOUR IN CHILD MORTALITY IN THE SLUMS OF KARACHI, PAKISTAN

The role of family health-seeking behaviour in under-five-year child mortality was explored through the combined approach of examining health-seeking behaviour regarding treatment generally, and in specific in relation to illness before death. A population-based case control study was carried out during the period 1993-1994 using 222 deaths from diarrhoea and acute respiratory illness (ARI) in children under five years of age in six slums of Karachi as cases, and 419 controls matched on age, disease (diarrhoea and ARI) and slum. Factors significantly associated (p<0.05) with child mortality in the multivariate analysis were: mothers changing healers quickly, using a traditional healer or an unqualified doctor and mothers to whom doctors did not explain the treatment, even when maternal education was controlled for. Seeking effective medical services is highly influential on whether the child survives or succumbs to ARI or diarrhoea. As mothers are the first providers of care, an attempt should be made to try and improve their skills through health education so that they can use simple and effective treatments for minor illnesses. They should also be taught to recognize potentially life-threatening conditions, to seek care early and to persist with treatment.

Work demands, job insecurity and sickness absence from work. How productive is the new, flexible labour force?

Background: We investigate one aspect of productivity – sickness absence – and ask whether job insecurity and high work demands are associated with increased sickness absence and, if so, whether mental or physical health mediates this association. We further investigate if having control at work modifies these associations.

The health effects of jobs : Status, working conditions, or both?

Background: This study investigates whether the association of job strain and insecurity with health differs by status.

Could better jobs improve mental health? A prospective study of change in work conditions and mental health in mid-aged adults

Objectives To investigate the extent improvement or deterioration in employee job security, control or workload is associated with a change in mental health. Design Self-report panel data (2000, 2004) on mental health (symptoms of depression and generalised anxiety) and job demands, control and insecurity. Changes in exposures and outcomes were calculated by subtracting wave 1 from wave 2 scores. Changes in mental health were regressed onto changes in work conditions, adjusting for confounders. Sensitivity analyses assessed reverse causation, floor and ceiling effects. Setting Two adjoining cities in south-east Australia. Participants 1975 employees aged 40–48 years, 50% (n=995) male. Results Improvements and deterioration in each work condition were associated with corresponding improvements or deterioration in mental health. The association between changes in job insecurity and symptoms of depression was B=0.386 (95% CI 0.245 to 0.527) and with anxiety symptoms was B=0.434 (95% CI 0.267 to 0.601). Similarly, changes in job control were associated with changes in depressive (B=−0.548; 95% CI −0.791 to −0.304) and anxiety symptoms (B=−0.608; 95% CI −0.896 to −0.319) as were changes in job demands (B depression=0.386; 95% CI 0.245 to 0.527; B anxiety=0.434; 95% CI 0.267 to 0.601). Excluding people with severe symptoms at baseline did not alter the findings; however, path analyses indicated that depression may precede a worsening of work conditions. Conclusion Among mid-aged employees, deteriorating work conditions may amplify population health burdens, especially anxiety. Furthermore, better quality jobs, combining an array of positive conditions, could alleviate major population health burdens.

Assessment of cardiovascular disease risk factors and diabetes mellitus in Australian prisons: is the prisoner population unhealthier than the rest of the Australian population?

Introduction: This paper compares the prevalence estimates of diabetes and cardiovascular disease (CVD) risk factors in the Indigenous and non‐Indigenous New South Wales (NSW) prisoner population in 1996 and 2001, and also compares the 2001 prevalence estimates with Australian population data.