The epidemiology of communicable disease in the Hunter New England region, New South Wales

Abstract

Background The Hunter New England (HNE) Local Health District (LHD) in New South Wales (NSW) faces many public health challenges. These challenges include infectious diseases, vectorborne diseases, zoonoses and other important diseases such as salmonellosis. The HNE region also faces social challenges that impact on the health of its residents such as the health inequalities experienced by Aboriginal and Torres Strait Islander people. Surveillance is a critical component in enabling public health practitioners to address these challenges. Through surveillance mechanisms, public health practitioners can observe trends over time, detect aberrations, develop hypotheses, reveal associations and identify risk groups. This informs public health action and can generate or influence the development of public health policy and programs. The HNELHD has a number of surveillance systems in place to enable surveillance of public health issues, however, examining the usefulness of current systems and developing new methods of surveillance are critical steps in disease control strategies. Methods A number of epidemiological studies utilising different methodologies and surveillance systems were undertaken to meet some of these public health challenges. To address the challenges of foodborne outbreaks detected through routine surveillance, an unmatched case-control study and two retrospective cohort studies were carried out. One of the cohort studies utilised a novel online survey to obtain information on illness and food consumption. In addition, a case-series investigation explored epidemiological links between cases of norovirus and food consumption. To meet the challenges of surveillance of the pathogens causing gastroenteritis and subsequent stool specimen collection for patients presenting to hospital with bloody diarrhoea, a retrospective cohort study was conducted. The aim of this study was to explore the predictors of stool specimen collection. The study utilised data linkage to link emergency department and laboratory surveillance data. 7 To meet the challenges of influenza surveillance, a formal evaluation of the healthdirect Australia influenza-like illness surveillance (ILI) system was undertaken, using the United States Centres for Disease Control and Prevention evaluation guidelines. A time-series analysis was utilised to compare the performance of healthdirect Australia influenza-like illness data to other established influenza surveillance systems. Results The foodborne outbreak investigations resulted in the detection and remediation of both a Salmonella and norovirus source that had been identified as the cause of illness in two outbreak investigations. The stool specimen collection study identified age and type of hospital a patient presented to were predictors of stool specimen collection. This will inform targeted public health interventions. The evaluation of the healthdirect Australia ILI surveillance system validated the usefulness of the system at a national, state and local level. There was strong support for jurisdictional level data. The analysis of the healthdirect Australia ILI data demonstrated that the healthdirect data was consistent with Flutracking and laboratory data but diverged during the pandemic. Conclusion The use of surveillance data provides a basis for the epidemiological investigation of public health issues in the HNELHD, including Salmonella, norovirus and influenza. The outcomes of these investigations can have a positive impact on the health of the residents in this region. Show more