Influenza outbreaks in aged care facilities in New South Wales in 2017: impact and lessons for surveillance.

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.

An outbreak of norovirus genogroup II associated with New South Wales oysters.

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.

Timeliness of Salmonella Typhimurium notifications after the introduction of routine MLVA typing in NSW.

Salmonella Typhimurium is the most common bacterial cause of gastrointestinal disease in NSW. Regular review of surveillance procedures ensures system objectives are met and informs improvements in system utility and efficiency. This paper assesses the timeliness and data completeness of NSW Salmonella Typhimurium surveillance after the routine introduction of multilocus variable repeat analysis (MLVA), a rapid sub-typing technique. MLVA results were available significantly earlier than alternate sub-typing techniques over the 2 years of this review. Accordingly, from a timeliness perspective, MLVA offers a favourable Salmonella Typhimurium sub-typing option in NSW. Further opportunities to improve timeliness and data completeness are identified. This paper was produced as part of a review of Salmonella Typhimurium surveillance in NSW for the period 2008-2009 by members of OzFoodNet based at Hunter New England Population Health. OzFoodNet is a national network established by the then Commonwealth Department of Health and Ageing in 2000 to enhance foodborne disease surveillance in Australia.

The health of Hunter Valley communities in proximity to coal mining and power generation, general practice data, 1998-2010.

AIM: An analysis of general practice data for rural communities in close proximity to coal mining and coal-fired power generation in the Hunter Valley region of NSW was conducted to identify unusual patterns of illness. METHODS: Bettering the Evaluation and Care of Health general practice consultation data from the Hunter Valley region for 1998-2010 were compared with data from all other rural NSW residents. RESULTS: There were no significantly higher rates of problems managed or medications prescribed for Hunter Valley region residents compared with the rest of rural NSW. Rates of respiratory problem management in the Hunter Valley region did not change significantly over time, while for all other rural NSW areas these rates significantly decreased. CONCLUSION: There was no evidence of significantly elevated health issues for residents in the Hunter Valley region of NSW. The diverging trend for respiratory problem management over time is worthy of further exploration.

Measles with a possible 23 day incubation period.

Measles virus (MV) eradication is biologically, technically and operationally feasible. An essential feature in understanding the chain of MV transmission is its incubation period, that is, the time from infection to the onset of symptoms. This period is important for determining the likely source of infection and directing public health measures to interrupt ongoing transmission. Long measles incubation periods have rarely been documented in the literature. We report on a previously healthy 11-year-old Australian boy who was confirmed with measles genotype D9 infection following travel in the Philippines. Epidemiological evidence supported an unusually long incubation period of at least 23 days and virological evidence was consistent with this finding. Although public health control measures such as post exposure prophylaxis, isolation and surveillance of susceptible individuals should continue to be based on the more common incubation period, a longer incubation period may occasionally explain an unexpected measles case.

Evaluating the utility of emergency department syndromic surveillance for a regional public health service.

Communicable disease monitoring and response activities must be based upon local public health surveillance systems, even during infectious disease emergence, natural disasters, and during bioterrorism events. The NSW Department of Health has developed an emergency department surveillance system intended to monitor important public health conditions during mass gatherings and to identify outbreaks of importance. An evaluation of this system conducted in the Hunter New England region of New South Wales emphasised its usefulness when it was focused on a limited number of syndromes of public health importance and during mass gatherings and public health disaster responses.

A structured framework for improving outbreak investigation audits.

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.

Egg-associated Salmonella outbreak in an aged care facility, New South Wales, 2008.

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.

Estimate of the number of Campylobacter infections in the Hunter region, NSW, 2004-2007.

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.

A norovirus outbreak associated with consumption of NSW oysters: implications for quality assurance systems.

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.

Mitigating the health impacts of a natural disaster--the June 2007 long-weekend storm in the Hunter region of New South Wales.

A severe storm that began on Thursday, 7 June 2007 brought heavy rains and gale-force winds to Newcastle, Gosford, Wyong, Sydney, and the Hunter Valley region of New South Wales. The storm caused widespread flooding and damage to houses, businesses, schools and health care facilities, and damaged critical infrastructure. Ten people died as a result of the storm, and approximately 6000 residents were evacuated. A natural disaster was declared in 19 local government areas, with damage expected to reach $1.5 billion. Additional demands were made on clinical health services, and interruption of the electricity supply to over 200,000 homes and businesses, interruption of water and gas supplies, and sewerage system pump failures presented substantial public health threats. A public health emergency operations centre was established by the Hunter New England Area Health Service to coordinate surveillance activities, respond to acute public health issues and prevent disease outbreaks. Public health activities focused on providing advice, cooperating with emergency service agencies, monitoring water quality and availability, preventing illness from sewage-contaminated flood water, assessing environmental health risks, coordinating the local government public health response, and surveillance for storm-related illness and disease outbreaks, including gastroenteritis. The local ABC (Australian Broadcasting Corporation) radio station played a key role in disseminating public health advice. A household survey conducted within a fortnight of the storm established that household preparedness and storm warning systems could be improved.

General practice intervention to increase opportunistic screening for chlamydia.

We describe an 18-month intervention that was designed to improve opportunistic screening for chlamydia in General Practice. Key strategies included engaging and informing general practitioners, adopting a simplified screening protocol, providing feedback on practice testing performance and developing resources for use with patients. This uncontrolled before and after study found that the overall impact on testing was modest and largely transient, and was insufficient to impact on the current chlamydia epidemic. Major additional measures would be required to further substantially increase testing levels. These could include financial incentives linked to screening performance and increased community awareness to increase patient demand for testing.

An outbreak of pulmonary tuberculosis in young Australians.

OBJECTIVE: To characterise a pulmonary tuberculosis (TB) cluster in the Hunter Area of New South Wales using a combination of traditional epidemiological methods and molecular typing. DESIGN, SETTING AND PARTICIPANTS: Review of all notifications of TB in the Hunter Area between January 1994 and June 2005, with a detailed analysis of cases among people born in Australia or New Zealand. MAIN OUTCOME MEASURES: Comparison of genotypes of Mycobacterium tuberculosis isolates; extent of TB cluster. RESULTS: Over the period studied, there were 72 TB notifications among people born in Australia or New Zealand. Genotypic testing was available for 20 of these cases, of which nine were confirmed to be part of a cluster. Two further cases for which genotyping was not available were epidemiologically linked to the cluster and regarded as probable cluster cases. Members of the cluster were relatively young (median age at diagnosis, 35 years; range, 21-57 years), and eight were women. Over the same period, there were 83 TB notifications among people born overseas, the majority being from Asia (47%) or central and eastern Europe (24%) (median age, 54 years; range, 9-63 years). CONCLUSION: Clinicians should maintain a high index of suspicion for pulmonary TB in a person presenting with a productive cough lasting more than 3 weeks, weight loss, haemoptysis, night sweats and chest pain, even if the person is not overseas-born or elderly. A comprehensive tuberculosis genotyping network at regional and national level in Australia could help identify clusters resulting from recent transmission.