Search

Abstract Background Outbreak investigation is a core function of public health agencies. Suboptimal outbreak investigation endangers both public health and agency reputations. While audits of clinical medical and nursing practice are conducted as part of continuous quality improvement, public health agencies rarely make systematic use of structured audits to ensure best practice for outbreak responses, and there is limited guidance or policy to guide outbreak audit. Methods A framework for prioritising which outbreak investigations to audit, an approach for conducting a successful audit, and a template for audit trigger questions was developed and trialled in four foodborne outbreaks and a respiratory disease outbreak in Australia. Results The following issues were identified across several structured audits: the need for clear definitions of roles and responsibilities both within and between agencies, improved communication between agencies and with external stakeholders involved in outbreaks, and the need for development of performance standards in outbreak investigations - particularly in relation to timeliness of response. Participants considered the audit process and methodology to be clear, useful, and non-threatening. Most audits can be conducted within two to three hours, however, some participants felt this limited the scope of the audit. Conclusion The framework was acceptable to participants, provided an opportunity for clarifying perceptions and enhancing partnership approaches, and provided useful recommendations for approaching future outbreaks. Future challenges include incorporating feedback from broader stakeholder groups, for example those of affected cases, institutions and businesses; assessing the quality of a specific audit; developing training for both participants and facilitators; and building a central capacity to support jurisdictions embarking on an audit. The incorporation of measurable performance criteria or sharing of benchmark performance criteria will assist in the standardisation of outbreak investigation audit and further quality improvement.

Introduction: A record number of influenza outbreaks in aged care facilities (ACFs) in New South Wales (NSW) during 2017 provided an opportunity to measure the health impact of those outbreaks and assess the quality of routinely available surveillance data., Methods: Data for all ACF influenza outbreaks in NSW in 2017 were extracted from the Notifiable Conditions Information Management System. The numbers of outbreaks, residents with influenza-like illness (ILI), hospital admissions and deaths were assessed. For each outbreak the attack rate; duration; timeliness of notification; resident and staff influenza vaccination coverage; and antiviral use for treatment or prophylaxis were analysed. Data were considered for NSW in total and separately for seven of the state's local health districts. Data completeness was assessed for all available variables., Results: A total of 538 ACF outbreaks resulted in 7,613 residents with ILI, 793 hospitalisations and 338 deaths. NSW outbreaks had a median attack rate of 17% and median duration of eight days. Data completeness, which varied considerably between districts, limited the capacity to accurately consider some important epidemiological and policy issues., Discussion: Influenza outbreaks impose a major burden on the residents and staff of ACFs. Accurate assessment of the year-to-year incidence and severity of influenza outbreaks in these facilities is important for monitoring the effectiveness of outbreak prevention and management strategies. Some key data were incomplete and strategies to improve the quality of these data are needed, particularly for: the number of influenza-related deaths among residents; resident and staff vaccination coverage prior to outbreaks; and recorded use of antiviral prophylaxis., (© Commonwealth of Australia CC BY-NC-ND.)

Introduction: Currently available antigen tests for norovirus (NoV) have excellent specificity but negative results do not always rule out infection. Real-time reverse transcription polymerase chain reaction (RT-PCR) is a useful method for detecting and genotyping NoV in humans and oysters. An outbreak of NoV associated with oyster consumption in northern New South Wales confirmed the value of real-time RT-PCR where immunochromatography (ICT) tests were negative., Methods: Eight cases of gastrointestinal illness in northern NSW, clinically suggestive of NoV infection, were associated with consumption of oysters. A joint environmental investigation was conducted by the New South Wales Food Authority and local council. One human sample was collected and tested for NoV using ICT and real-time RT-PCR. Oyster samples were tested for NoV utilising real-time RT-PCR., Results: The patient with a stool sample had NoV genogroup II (GII) confirmed by real-time RT-PCR after testing negative by ICT. Illness in all cases was consistent with NoV with median incubation and duration of 36 and 50.5 hours respectively. All cases consumed oysters that were harvested from the same area. Three oyster samples from the harvest area were also positive for NoV GII. A nearby leaking sewer line was identified as the likely source of the contamination with hydrological studies confirming its potential to contaminate implicated oyster leases., Conclusion: This investigation confirmed the value of real-time RT-PCR testing of human specimens where ICT tests are negative and clinical illness is suggestive of NoV infection. NoV real-time RT-PCR and epidemiological evidence effectively linked human infection with oyster contamination to motivate a thorough environmental investigation and appropriate action to mitigate further public health risk., (copyright@health.gov.au)

Objectives: Campylobacteriosis is not notifiable in NSW and the number of cases of Campylobacter disease is thus not well described., Methods: De-identified campylobacteriosis records for 2004-2007 were requested from laboratories in the Hunter region of NSW. Based on notifying laboratory, a Salmonella notification weighting was applied to laboratory-confirmed campylobacteriosis cases to provide an overall estimate of Campylobacter disease in the area., Results: The estimated median of the annual number of laboratory-confirmed campylobacteriosis cases was 788 (range 700-1022). The ratio of estimated Campylobacter cases to Salmonella notifications was 5.5 : 1., Conclusion: Campylobacter infection causes considerable disease in the Hunter, and likely in NSW. Regular review of Campylobacter laboratory results may be valuable.

Salmonellosis is a bacterial disease that causes acute gastroenteritis, with sudden onset of headache, abdominal pain, diarrhoea, nausea and sometimes vomiting. Infection is often associated with the consumption of foods prepared using raw eggs. During July to August 2008 an outbreak at an aged care facility (ACF) in New South Wales was confirmed as Salmonella Typhimurium phage type 44 (Stm 44) in eight of 45 residents. Two additional probable cases also occurred. Cases were located in each unit of the ACF and for 5 cases, onset of diarrhoea was between 45 to 64 hours (median of 46 hours) after consumption of a dessert containing raw eggs. Onset for 5 further cases occurred up to 9 days after this meal. Eggs were supplied to the ACF from a local farm. Stm 44 was detected on an egg in an unopened box at the ACF from this supplier. The raw-egg dessert was epidemiologically implicated as the likely source of the Salmonella and delayed onset cases may have resulted from ingestion of a smaller dose of Salmonella, or ongoing transmission through cross-contamination of kitchen machinery or surfaces. This outbreak demonstrates that inadequate cooking of eggs continues to pose a risk for Salmonella infection in settings with vulnerable populations. The findings of the investigation provide support for the importance of food safety regulations and demand further advocacy for measures to reduce the risks associated with the distribution, storage and preparation of shell eggs.

Norovirus is a common cause of gastroenteritis outbreaks associated with raw shellfish consumption. In Australia there have been several reports of norovirus outbreaks associated with oysters despite the application of regulatory measures recommended by Food Standards Australia New Zealand. This study describes an outbreak of norovirus gastroenteritis following the consumption of New South Wales oysters. In September 2007, OzFoodNet conducted a cohort study of a gastroenteritis outbreak amongst people that had dined at a Port Macquarie restaurant. Illness was strongly associated with oyster consumption, with all cases having eaten oysters from the same lease (RR undefined, p < 0.0001). Norovirus was detected in a faecal specimen. Although no pathogen was identified during the environmental investigation, the source oyster lease had been closed just prior to harvesting due to sewage contamination. Australian quality assurance programs do not routinely test oysters for viral contamination that pose a risk to human health. It is recommended that the feasibility of testing oysters for norovirus, particularly after known faecal contamination of oyster leases, be assessed.