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Gillian Hall

Publications and source records attributed to Gillian Hall.

14 recordsLinked to original sources
PubMed2006

A comparison of methods for calculating population exposure estimates of daily weather for health research.

BACKGROUND: To explain the possible effects of exposure to weather conditions on population health outcomes, weather data need to be calculated at a level in space and time that is appropriate for the health data. There are various ways of estimating exposure values from raw data collected at weather stations but the rationale for using one technique rather than another; the significance of the difference in the values obtained; and the effect these have on a research question are factors often not explicitly considered. In this study we compare different techniques for allocating weather data observations to small geographical areas and different options for weighting averages of these observations when calculating estimates of daily precipitation and temperature for Australian Postal Areas. Options that weight observations based on distance from population centroids and population size are more computationally intensive but give estimates that conceptually are more closely related to the experience of the population. RESULTS: Options based on values derived from sites internal to postal areas, or from nearest neighbour sites--that is, using proximity polygons around weather stations intersected with postal areas--tended to include fewer stations' observations in their estimates, and missing values were common. Options based on observations from stations within 50 kilometres radius of centroids and weighting of data by distance from centroids gave more complete estimates. Using the geographic centroid of the postal area gave estimates that differed slightly from the population weighted centroids and the population weighted average of sub-unit estimates. CONCLUSION: To calculate daily weather exposure values for analysis of health outcome data for small areas, the use of data from weather stations internal to the area only, or from neighbouring weather stations (allocated by the use of proximity polygons), is too limited. The most appropriate method conceptually is the use of weather data from sites within 50 kilometres radius of the area weighted to population centres, but a simpler acceptable option is to weight to the geographic centroid.

Health Status↗
PubMed2006

Lymphoepithelioma-like carcinoma of the skin: a case with lymph node metastases at presentation.

We report a case of a primary lymphoepithelioma-like carcinoma (LELC) of the skin. The patient was a 73-year-old man with a lump on his back for 18 months. A biopsy and subsequent excision was performed. He also had axillary node clearance for metastatic disease. The tumor was composed of islands of pleomorphic cells with a lymphocytic infiltrate. Differential diagnoses included squamous cell carcinoma, adnexal carcinoma, Merkel cell tumors, lymphoepithelial lesions, lymphomas, and skin metastases. The histopathologic and immunohistochemical features were those of a LELC of the skin. It was negative for Epstein-Barr virus. Just over 30 cases of primary LELCs arising in the skin have been reported with only 1 documented fatality. We report a case with extensive vascular involvement and bilateral lymph node metastases.

Aged↗
PubMed2005

Estimating the burden of acute gastroenteritis, foodborne disease, and pathogens commonly transmitted by food: an international review.

The burden of foodborne disease is not well defined in many countries or regions or on a global level. The World Health Organization (WHO), in conjunction with other national public health agencies, is coordinating a number of international activities designed to assist countries in the strengthening of disease surveillance and to determine the burden of acute gastroenteritis. These data can then be used to estimate the following situations: (1) the burden associated with acute gastroenteritis of foodborne origin, (2) the burden caused by specific pathogens commonly transmitted by food, and (3) the burden caused by specific foods or food groups. Many of the scientists collaborating with the WHO on these activities have been involved in quantifying the burden of acute gastroenteritis on a national basis. This article reviews these key national studies and the international efforts that are providing the necessary information and technical resources to derive national, regional, and global burden of disease estimates.

Australia↗
PubMed2005

Prevalence of diarrhoea in the community in Australia, Canada, Ireland, and the United States.

BACKGROUND: Studies in several countries have estimated the prevalence of diarrhoea in the community. However, the use of different study designs and varying case definitions has made international comparisons difficult. METHODS: Similar cross-sectional telephone surveys were conducted in Australia, Canada, Ireland (including Northern Ireland), and the United States over 12 month periods between 2000 and 2002. Each survey asked about diarrhoea in the four weeks before the interview. For this comparative analysis, uniform definitions were used. RESULTS: Questionnaires were completed for 6087 respondents in Australia, 3496 in Canada, 9903 in Ireland, and 14,647 in the United States. In the four weeks prior to interview, at least one episode of diarrhoea was reported by 7.6% of respondents in Canada, 7.6% in the United States, 6.4% in Australia, and 3.4% in Ireland. The prevalence of diarrhoea was consistently higher in females. In all countries, the prevalence of diarrhoea was highest in children <5 years and lowest in persons > or =65 years of age. When diarrhoea and vomiting was considered, the prevalence was almost identical in the four studies (range: 2.0-2.6%). Despite different health care structures, a similar proportion of respondents sought medical care (approximately one in five). Antibiotic usage for the treatment of diarrhoea was reported by 8.3% of respondents in the United States, 5.6% in Ireland, 3.8% in Canada, and 3.6% in Australia. CONCLUSIONS: Diarrhoea is a common illness among persons in the community in Australia, Canada, Ireland, and the United States. With similar methodologies and a standard case definition, age and sex patterns and health care seeking behaviour were remarkably consistent between countries.

Adolescent↗
PubMed2005

Estimating foodborne gastroenteritis, Australia.

We estimated for Australia the number of cases, hospitalizations, and deaths due to foodborne gastroenteritis in a typical year, circa 2000. The total amount of infectious gastroenteritis was measured by using a national telephone survey. The foodborne proportion was estimated from Australian data on each of 16 pathogens. To account for uncertainty, we used simulation techniques to calculate 95% credibility intervals (CrI). The estimate of incidence of gastroenteritis in Australia is 17.2 million (95% confidence interval 14.5-19.9 million) cases per year. We estimate that 32% (95% CrI 24%-40%) are foodborne, which equals 0.3 (95% CrI 0.2-0.4) episodes per person, or 5.4 million (95% CrI 4.0-6.9 million) cases annually in Australia. Norovirus, enteropathogenic Escherichia coli, Campylobacter spp., and Salmonella spp. cause the most illnesses. In addition, foodborne gastroenteritis causes approximately 15,000 (95% CrI 11,000-18,000) hospitalizations and 80 (95% CrI 40-120) deaths annually. This study highlights global public health concerns about foodborne diseases and the need for standardized methods, including assessment of uncertainty, for international comparison.

Australia↗
PubMed2004

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.

Australia↗
PubMed2003

Suppression of allergen reactive Th2 mediated responses and pulmonary eosinophilia by intranasal administration of an immunodominant peptide is linked to IL-10 production.

The potential to induce systemic tolerance following exposure of the airway mucosa to soluble antigen, may be applied therapeutically for the treatment of allergic disease. Since the use of allergen can trigger IgE mediated inflammation, we investigated whether mucosal delivery of a peptide, containing an immunodominant epitope of the Der p1 allergen of house dust mite, can lead to CD4(+) Th2 cell tolerance and thus protect against airway inflammatory responses to inhalant allergen. The administration of microencapsulated peptide to the nasal mucosa of mice, protected against airway inflammation, with significant reductions in eosinophil infiltration into the airways following allergen challenge. Der p1 specific antibody levels in sera were not modulated. Allergen reactive CD4(+) T cells expressed a tolerized phenotype, with reduction in levels of the cytokines, IL-5, IL-13 and IFN-gamma although IL-10 levels were increased. The mucosal administration of a peptide containing an immunodominant region of an allergen can protect against the induction of systemic and local inflammatory responses to allergen challenge.

Allergens↗
PubMed2003

Biases affecting the proportional reporting ratio (PPR) in spontaneous reports pharmacovigilance databases: the example of sertindole.

BACKGROUND: Automated measures of reporting disproportionality in databases of spontaneous reports of adverse drug reactions are an emerging tool to identify drug-related alerts. Sertindole, a new atypical neuroleptic known to prolong the QT interval, was suspended in November 1998 because the proportion of reports of fatal reactions suggesting arrhythmia among all reports with sertindole was almost ten times higher than that for other atypical neuroleptics in the UK. This excess risk was not predicted in preclinical data and had not been found in premarketing trials. METHOD: Reporting patterns over time were analysed. Prescription Event Monitoring (PEM) studies and a large retrospective cohort allowed for the comparison of actual death rates with atypical neuroleptics, and to assess which proportion of the deaths that occurred were reported. RESULTS: There were indications of possible skewing of reporting related to notoriety, surveillance and market size effects. Death rates in PEM studies were essentially similar between sertindole and other neuroleptics. Cardiac deaths had been two to three times more often reported than other causes of death. CONCLUSION: Proportional reporting ratios indicate differential reporting of possible reactions, not necessarily differential occurrence. There was no indication of an actual increase of risk of all causes or cardiac deaths during sertindole treatment, but only an increased risk of its being reported. The suspension of sertindole was rescinded by Committee on Proprietary Medicinal Products (CPMP) in October 2001.

Adverse Drug Reaction Reporting Systems↗
PubMed2002

Scavenger receptor-specific allergen delivery elicits IFN-gamma-dominated immunity and directs established TH2-dominated responses to a nonallergic phenotype.

BACKGROUND: Immunotherapeutic approaches to allergy consist of reliably changing allergen-specific T(H)2 immunity associated with secretion of IL-4, IL-5, and IL-13, along with IgE antibodies in atopic individuals to T(H)1 immunity. Our earlier data show that targeting of protein antigens to antigen-presenting cells (APCs), such as macrophages, by means of scavenger receptors (SRs) results in a pronounced T(H)1 immunity. Here we demonstrate a novel experimental approach for the conversion of T(H)2 immunity to T(H)1 immunity by using SR delivery of allergens. OBJECTIVES: We sought to show that targeting of allergens by means of SRs to APCs triggers T(H)1 immunity and that an established T(H)2 immunity to the Der p 1-immunodominant peptide 111-139 (p1, 111-139) can be modulated to a nonallergic T(H)1 phenotype. METHODS: Analysis of the T cell-derived cytokines IL-4, IL-5, IL-13, and IFN-gamma in response to p1, 111-139 in C57BL/6 mice 7 to 42 days after immunization, measurement of specific antibody responses, eosinophilic infiltrate, and skin hypersensitivity in response to allergen challenge constitute the parameters of in vivo immunity. RESULTS: We show that p1, 111-139, when delivered to APCs by means of SR, elicits a T(H)1-dominant immunity. If it is delivered to APCs either after chemical coupling to SR ligands or by means of mere coadsorption on alum in the presence of an SR ligand, the established T(H)2 immunity can be modified to T(H)1 immunity. CONCLUSIONS: SR-mediated delivery of allergens has immunotherapeutic potential that may be usable in atopic individuals.

Animals↗
PubMed2002

Kinetics and mode of peptide delivery via the respiratory mucosa determine the outcome of activation versus TH2 immunity in allergic inflammation of the airways.

BACKGROUND: Specific immunotherapy involving systemic injection of allergen, though highly effective, can cause severe side effects due to IgE-mediated activation of effector cells. Allergen-derived peptides might provide a safer alternative. We have investigated the use of mucosally delivered peptide to induce CD4(+) T(H)2 cell tolerance and thus protect against allergen-induced airway inflammation. OBJECTIVE: The purpose of this study was to investigate whether intranasal administration of an allergen-derived peptide, either alone or adsorbed to chitosan, can prevent the induction of T(H)2-mediated pulmonary inflammation after sensitization and challenge of the airways with allergen. METHODS: Mice were given (intranasally) a peptide containing an immunodominant epitope of the Dermatophagoides pteronyssinus (Der p) 1 allergen, either as soluble antigen or adsorbed to chitosan, before sensitization and allergen challenge. Pulmonary inflammation, antigen-specific CD4(+) T-cell responses, and antibody levels in sera were then determined. RESULTS: Mice given peptide adsorbed to chitosan had significant reductions in airway eosinophilia, which correlated with reduced levels of IL-4 and IL-5 in the bronchoalveolar lavage fluid. There was decreased recruitment of activated CD4(+) T cells into the airways after allergen challenge, which correlated with a loss of Der p 1-specific T-cell cytokine responses in the periphery and the localized production of IL-10 by antigen-specific T cells in bronchial lymph nodes. Induction of peripheral T-cell tolerance was preceded by transient T-cell activation and IFN-gamma production. CONCLUSION: Our data demonstrate that suppression of airway inflammation by intranasal administration of peptide antigen adsorbed to chitosan is initiated by transient T-cell activation and maintained by the production of IL-10 by antigen-specific T cells in the draining lymph nodes.

Administration, Intranasal↗
PubMed2002

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.

Adolescent↗