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.

NSW Annual vaccine-preventable disease report, 2011.

AIM: To describe the epidemiology of selected vaccine-preventable diseases in NSW for 2011. METHODS: Data from the NSW Notifiable Conditions Information Management System were analysed by: local health district of residence, age, Aboriginality, vaccination status, and organism, where available. Risk factor and vaccination status data were collected by public health units for case-patients following notification under the NSW Public Health Act 1991*. RESULTS: Outbreaks of measles and pertussis were reported in 2011, associated with unimmunised groups for measles, and a variety of factors for pertussis. Notification rates for other selected vaccine-preventable diseases remained stable. CONCLUSION: Vaccine-preventable diseases are generally well controlled in NSW. However, pertussis remains an important public health issue. To prevent measles high population vaccination coverage, including vaccination in risk groups, is essential.

NSW annual vaccine-preventable disease report, 2010.

AIMS: To describe trends in case notification data for vaccine-preventable diseases in NSW for 2010. METHODS: Risk factor and vaccination status data were collected from cases through public health unit follow-up. Data from the NSW Notifiable Conditions Information Management System (NCIMS) were analysed by: local health district of residence; age; vaccination status; and sub-organism, where available. RESULTS: Outbreaks of measles and pertussis were notified in 2010, associated with unimmunised groups (measles) or as a result of waning immunity (pertussis). CONCLUSION: With the exception of pertussis, most vaccine-preventable disease notifications remain low in NSW. Ensuring high levels of vaccination for travellers is important to prevent future outbreaks of vaccine-preventable disease, particularly measles.

Reflections on public health surveillance of pandemic (H1N1) 2009 influenza in NSW.

Surveillance has a fundamental role during public health emergencies to provide accurate and relevant information to guide decision making. For each phase of the NSW response to the pandemic H1N1 (2009) influenza there were significant differences in the public health surveillance objectives and response mechanisms. Consequently each phase placed a different emphasis on the various sources and types of surveillance information which were collected and reported upon. We examine whether the NSW public health surveillance systems were able to inform effective public health management throughout all phases of the pandemic (H1N1) 2009 influenza.

NSW Annual Vaccine-Preventable Disease Report, 2009.

AIMS: To describe trends in case notification data for vaccine-preventable diseases in NSW for 2009. METHODS: Risk factor and vaccination status data was collected from cases through public health unit follow-up. Data from the NSW Notifiable Diseases Database were analysed by: area health service of residence; age; vaccination status; and sub-organism, as appropriate for the period 1991-2009. RESULTS: The incidence of vaccine-preventable disease has declined over time. Outbreaks of measles and pertussis occur in the community, associated with unimmunised groups (measles) or as a result of waning immunity (pertussis). CONCLUSION: Regular reporting of vaccine-preventable disease surveillance data will help inform control strategies in NSW.

Cellulitis in childhood invasive pneumococcal disease: a population-based study.

AIM: There are few detailed data on the age-specific incidence and clinical pattern of pneumococcal cellulitis in children. We conducted a retrospective review of cellulitis as a subset of prospectively collected laboratory-identified invasive pneumococcal disease (IPD) and performed a systematic review of published literature. METHODS: Prospective laboratory surveillance in urban regions of New South Wales, Australia, 1 June 1997-31 December 2001. Medical notes reviewed for each identified case and defined literature search strategy applied. RESULTS: There were 1067 cases of IPD in children aged 0-17 years; 38 (3.3%) were cellulitis (32 periorbital, 6 buccal). Compared with other types of IPD, a greater proportion of cellulitis cases occur in children<2 years (30/38, 79% vs. 617/1029, 60.0%; P=0.004) in whom underlying illness was less common (0/30, 0% vs. 53/590, 9%; P=0.06). Initially, another diagnosis was made in 13 (34%) of cases; only five had a lumbar puncture, all normal. Of the 239 cases of pneumococcal cellulitis documented in the literature, 28 (11.7%) had the diagnosis made by means other than positive blood culture and 95% were facial or orbital with underlying illness (6%) and associated meningitis (1.9%) uncommon. CONCLUSION: Cellulitis is an uncommon focus in IPD in children, and is almost always facial. Most cases occur under 2 years of age, are seldom associated with meningitis or other complications, and are frequently not recognised on admission.