Health Protection in NSW

Abstract

Health protection involves the prevention and control of threats to health from both communicable diseases and the environment. I conducted a variety of projects across the breadth of Health Protection within NSW Health between March 2016 and October 2017 to fulfil the requirements of the Masters of Philosophy in Applied Epidemiology (MAE).

My first placement was within the Enteric and Zoonotic Diseases division of the Communicable Disease Branch. A large outbreak of Salmonella Saintpaul occurred in Australia between December 2015 and June 2016 with a total of 547 confirmed and probable cases notified. When I commenced in March 2016 this outbreak had been underway since December 2015 with no clear vehicle of infection identified. I conducted a case-control study including 72 confirmed cases and 144 controls from SA and NSW which identified that Mung bean sprout consumption was reported by 40.6% (28/69) of cases and 4.3% (6/140) of controls (OR 14.6, 95% CI 5.9-39.4). This outbreak led to a recall of mung bean sprouts from an implicated sprouter in South Australia and public messaging about the safe preparation and consumption of bean sprouts.

In July 2016 six states and territories of Australia were affected by a large outbreak of Salmonella Hvittingfoss with 144 confirmed and suspected cases notified. I led a coordinated multi-jurisdictional investigation to identify the source of infection and control the outbreak, including conducting a case-control study. The epidemiological, microbiological and environmental investigation implicated consumption of rockmelon (OR 7.2, 95%CI 1.87-27.93) from a single producer as a significant risk for infection. The producer initiated a voluntary recall of the product.

My second placement was in the Environmental Health Branch of Health Protection. I completed a review of the epidemiology of notifications in NSW to provide a snapshot of elevated blood lead levels in NSW and to inform an evaluation of the NSW elevated blood lead surveillance system. There were 9,486 notifications of elevated blood lead from 1997–2016, with an average annual notification rate of 6.9 per 100,000. I analysed notification data for by age, sex, geographic area, exposure and occupation and compared notification rates over time and between geographic regions. I identified several limitations with the dataset that made it difficult to analyse notification rates, particularly by risk and exposure history and by blood lead level, and made recommendations to improve the data collection system. I also collected qualitative data about the function of the blood lead surveillance system by conducting face-to-face interviews with key stakeholders throughout NSW. Key areas for improvement in the system included changes to the way data is entered into the surveillance system, greater guidance for public health units on following up notifications, a review of the information collected on exposure, and guidance regarding liaising with occupational health regulatory agencies to ensure follow-up of occupational notifications.

Through completing these projects, I made valuable contributions to protecting the health of NSW residents.