The value of universal screening for COVID-19 cases on cruise ships during outbreaks.

OBJECTIVES: To describe the impact of universal screening for coronavirus disease 2019 (COVID-19) on passengers on cruise ships docking in Sydney, Australia, during 2022 that experienced a significant outbreak of COVID-19. Type of program or service: Cruise ship disease surveillance Methods: Case series, based on analysis of cruise ship voyages where universal screening of passengers was requested by a NSW health authority and undertaken by the cruise ship. RESULTS: Of 111 voyages in 2022, three fit the definition for this study. Universal screening during these voyages resulted in the detection of up to 1.8 times the number of existing COVID-19 cases, increasing attack rates of the three voyages from 14% to 24%; 13% to 28%; and 3% to 8% respectively. Case demographics showed an even gender distribution, with a majority 70 years or older. Asymptomatic case percentage ranged from 2% to 54%, with age and gender not associated with symptomatic status. Almost all cases were reported as being fully vaccinated. Genomic testing of cases showed multiple lineages of COVID-19 circulating in all three voyages. LESSONS LEARNT: Public health authorities, the cruise industry and passengers should be aware that a large number of unidentified cases of COVID-19 may disembark from a cruise ship that has experienced a large outbreak of the virus. These cases can seed the infection into vulnerable communities. Universal screening as part of the response to a significant outbreak will help identify cases and limit the spread of COVID-19.

Community Outbreak of Pseudomonas aeruginosa Infections Associated with Contaminated Piercing Aftercare Solution, Australia, 2021.

In April 2021, the South Eastern Sydney Local Health District Public Health Unit (Sydney, New South Wales, Australia) was notified of 3 patients with Pseudomonas aeruginosa infections secondary to skin piercings performed at the same salon. Active case finding through laboratories, clinician alerts, and monitoring hospital visits for piercing-related infections identified additional cases across New South Wales, and consumers were alerted. We identified 13 confirmed and 40 probable case-patients and linked clinical isolates by genomic sequencing. Ten confirmed case-patients had used the same brand and batch of aftercare solution. We isolated P. aeruginosa from opened and unopened bottles of this solution batch that matched the outbreak strain identified by genomic sequencing. Piercing-related infections returned to baseline levels after this solution batch was recalled. Early outbreak detection and source attribution via genomic sequencing are crucial for controlling outbreaks linked to contaminated products. Manufacturing standards for nonsterile cosmetic products and guidance for piercing aftercare warrant review.

Investigation of a legionellosis outbreak in Sydney CBD - a brief report.

OBJECTIVE: To identify and control a source of Legionella in Sydney CBD. METHODS: Clinical, epidemiological, environmental and genomic techniques were employed to identify cases and the source of Legionella. RESULTS: Eleven legionellosis cases were linked to Sydney CBD with a median age of 69 years. All were hospitalised and had risk factors for Legionella infection. Eight of 11 cases identified as male. Genomic analysis linked three cases to a contaminated cooling water source in Sydney CBD, with a further case infected with a similar strain to that found in Sydney CBD. Another case, although epidemiologically linked to Sydney CBD, was infected with a genomically different strain to that found in Sydney CBD. Six other cases had no viable sample for genomic analysis. CONCLUSION/IMPLICATIONS FOR PUBLIC HEALTH: An outbreak of legionellosis is a serious public health threat that requires rapid investigation and environmental control. We were able to identify a source in Sydney CBD through the application of clinical, epidemiological, environmental and genomic techniques. Genomic analysis is a powerful tool that can be used to confirm the source location but requires close collaboration between clinicians, public health units and microbiologists to recover viable sputum cultures from cases diagnosed with legionellosis.

Legionella pneumophila serogroup 1 infection associated with the use of an apartment building spa pool.

Background: Legionnaires' disease is a notifiable condition in New South Wales (NSW), Australia; clinicians and laboratories are required to report the disease to NSW Health. We describe the investigation of a sporadic case associated with the use of a communal spa pool in the case's apartment building complex and the use of whole genome sequencing to examine relatedness between clinical and environmental Legionella pneumophila serogroup 1 (Lp1) strains. Methods: In February 2018, a confirmed case of Lp1 infection was notified in a man in his 60s hospitalised with pneumonia. We asked the clinical team to obtain sputum in the event we found a potential source. The case described the use of the communal spa pool in his apartment building on two occasions during the putative exposure period. Environmental Health Officers from the Public Health Unit inspected the spa pool and found that the free chlorine level was well below the recommended concentration; a water sample was submitted for microbial analysis. Results: Lp1 was grown from the case's sputum and microbial analysis of the spa water sample found Lp1 at a concentration of 20 CFU/mL. The human and environmental isolates were subjected to whole genome sequencing and found to be highly genomically related. There was no other plausible environmental source of legionella. Conclusions: Whole genome sequencing of the clinical and environmental Lp1 isolates implicated a contaminated spa pool as the source of the case's exposure. This strongly supports the application of whole genome sequencing to the investigation of single cases of legionellosis. Communal spa pools in apartment buildings are not regulated in most Australian jurisdictions but must be considered to pose a potential legionella risk if improperly maintained.

The value of active follow up of a newly acquired hepatitis B infection - lessons for current approaches.

Abstract: The standard practice of blood borne virus (BBV) follow-up in New South Wales is a passive approach of general-practitioner-led testing. The value of this approach is unknown. We undertook an active contact tracing method with the aims of investigating a potential hepatitis B source, along with accurately measuring the participation rate, to consider the value of this and other follow-up methods for future BBV investigations. Investigation of a newly-acquired hepatitis B infection was undertaken at a dental practice identified as a possible exposure site. To screen for hepatitis B infection among potential source or co-exposed clients, we actively followed up with staff and clients of the practice to request they undertake hepatitis B serology. Eligible staff and clients received up to four phone calls and were provided with a pathology request form by the public health unit (PHU). Access to free serology was offered to people who did not have access to Medicare. Reminder calls were made if serology results were not received by the PHU. As the ordering doctor, the public health physician was responsible for providing results and referring for follow-up care. Of 160 clients, 63 (39%) undertook hepatitis B serology. Of these 63, none were found to have hepatitis B infection. It was estimated the active investigation involved an extra 430 hours of PHU staff time at a cost in Australian dollars of $30,000. Active follow-up allows an accurate participation rate to be documented. Despite intense active follow-up, only 39% of clients undertook testing, bringing into question the yield of the usual approach in which active follow-up of potential mass BBV exposures is not undertaken. While active follow-up is resource intensive, it should be considered where the risks and consequences from the BBV infection are high.

Circulation of enterovirus D68 (EV-D68) causing respiratory illness in New South Wales, Australia, between August 2018 and November 2019.

The incidence of enterovirus D68 (EV-D68) in New South Wales, Australia, is unknown. As part of a state-wide surveillance program, enterovirus positive diagnostic specimens were assessed from patients presenting to hospitals with respiratory and meningitis syndromes from August 2018 to November 2019. Diagnostic enterovirus positive samples were collected from 339 patients and re-extracted followed by targeted PCR across the whole EV-D68 genome (7.4 kb). Obtained amplicons (n=208) were sequenced using Illumina sequencing technology and the phylogenetic relationships analysed relative to EV-D68 Fermon strain. We identified EV-D68 in 31 patients, both children (n=27) and adults (n=4). Phylogenetically, the majority (n=30) were from subclade B3, the same as that causing outbreaks of EV-D68 across the USA and Europe during 2018. These data strengthen the importance of having an active enterovirus surveillance network.

Between the sea and the sky: A social practice investigation into health behaviours during cruise travel.

ISSUE ADDRESSED: The COVID-19 pandemic has highlighted organised cruise holidays as perfect incubators for microbiological infections due to the constant socialising within closed spaces. Little is known about people's health behaviours and perceptions during cruise holidays. METHODS: Narrative group interviews and respondent photo diary exercises were conducted with families (n = 25) residing in different areas across metropolitan NSW, Australia. Guided by a social practice theoretical approach we undertook a thematic analysis that identifies reasons for choosing a cruise, health considerations and behaviours in relation to cruise travel and awareness of official cruise health information. RESULTS: Cruise travel included a licence to abandon cautious behaviours, reinforced by confidence in the cruise organiser's risk management ability. Health concerns were not a high priority for participants and were mainly understood in terms of eating healthy, modest exercise, managing seasickness and having adequate supplies of medications. Awareness of official cruise health and risk information was largely non-existent. CONCLUSION: Understanding how travel health practices emerge and are likely to be modifiable produces health-promoting awareness and intervention efforts that recognise and link with people's ideas about cruise holidays as times of fun, leisure, relaxation, without interfering with or imposing on them. SO WHAT?: This study highlights the importance of developing health communication and promotion strategies that are responsive to the interconnected meanings, competencies and materials that have a bearing on how cruise travellers understand and enact health-related behaviours in preparation for and during a cruise holiday.

Bondi and beyond. Lessons from three waves of COVID-19 from 2020.

OBJECTIVES: To describe local operational aspects of the coronavirus disease 2019 (COVID-19) response during the first three waves of outbreaks in New South Wales (NSW), Australia, which began in January, July and December 2020. Type of program or service: Public health outbreak response. METHODS: Narrative with epidemiological linking and genomic testing. RESULTS: Epidemiological linking and genomic testing found that during the first wave of COVID-19 in NSW, a large number of community transmissions went undetected because of limited testing for the virus and limited contact tracing of cases. The second wave of COVID-19 in NSW emerged following reintroduction from the second wave in Victoria, Australia in July 2020, and the third wave followed undetected introduction from overseas. By the second and third waves, cases could be more effectively detected and isolated through an increased ability to test and contact trace, and to rapidly genomic sequence severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolates, allowing most cases to be identified and epidemiologically linked. This greater certainty in understanding chains of transmission resulted in control of the outbreaks despite less stringent restrictions on the community, by using a refined strategy of targeted shutdown, restrictions on cases, their close contacts, identified hotspots and venues of concern rather than a whole of community lockdown. Risk assessments of potential transmission sites were constantly updated through our evolving experience with transmission events. However, this refined strategy did leave the potential for large point source outbreaks should any cases go undetected. [Addendum] A fourth wave that began in Sydney in June 2021 challenged this strategy due to the more transmissible nature of the Delta variant of SARS-CoV-2. LESSONS LEARNT: A wave of COVID-19 infections can develop quickly from one infected person. The community needs to remain vigilant, adhering to physical distancing measures, signing in to venues they visit, and getting tested if they have any symptoms. Signing out of venues on exit allows public health resources to be used more efficiently to respond to outbreaks.

Risk factors leading to COVID-19 cases in a Sydney restaurant.

OBJECTIVE: To explore the factors associated with the transmission of SARS-CoV-2 to patrons of a restaurant. METHODS: A retrospective cohort design was undertaken, with spatial examination and genomic sequencing of cases. The cohort included all patrons who attended the restaurant on Saturday 25 July 2020. A case was identified as a person who tested positive to a validated specific Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) nucleic acid test. Associations were tested using chi-squared analysis of case versus non-case behaviours. RESULTS: Twenty cases were epidemiologically linked to exposure at the restaurant on 25 July 2020. All cases dined indoors. All cases able to be genomic sequenced were found to have the same unique mutational profile. Factors tested for an association to the outcome included attentiveness by staff, drink consumption, bathroom use and payment by credit card. No significant results were found. CONCLUSION: Indoor dining was identified as a key factor in SARS-CoV-2 transmission, and outdoor dining as a way to limit transmission. Implications for public health: This investigation provides empirical evidence to support public health policies regarding indoor dining.

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.

A multiple site community outbreak of COVID-19 in Sydney, Australia.

OBJECTIVE: To investigate an outbreak of COVID-19 in Sydney, Australia. METHODS: Epidemiological linking and analysis of cases of COVID-19 across multiple outbreak sites. RESULTS: Fifteen cases of COVID-19 and 41 contacts were identified and linked in a cluster that included one workplace and five households. The mean incubation period in the cases ranged from 4.6 to 6.4 days, while the median incubation period was shorter, ranging from 3 to 5 days. The overall range of incubation periods was 2 to 12 days. Differential attack rates were found within households (86% adults vs. 9% children) and workplace (32%) settings. Conclusions and implications for public health: Our investigation links cases between multiple households and a workplace. When exploring these links using a rapid workplace assessment, real-time cluster data along with objective measurements of exposure, such as with the Australian Government COVIDSafe app, may have allowed these links to be identified more readily and potentially reduced further spread of COVID-19. We found age as a factor for infection, with children being less likely to both acquire SARS-CoV-2 infection and to develop symptoms. This finding aids in our understanding of how the virus affects children and cautiously supports face-to-face classroom teaching.

Using a computerised database (REDCap) to monitor influenza vaccination coverage of healthcare workers and staff in South Eastern Sydney Local Health District.

Objective New South Wales (NSW) experienced a severe influenza season in 2017. In 2018, NSW Health implemented a campaign to improve healthcare worker (HCW) influenza vaccination coverage. The South Eastern Sydney Local Health District (LHD) trialled a centralised online database to monitor HCW uptake of the vaccination. This paper outlines how the monitoring system was chosen and developed, the process of implementation and the effectiveness of the system in this setting. Methods A literature review was conducted to identify an appropriate database. Stakeholder working groups took place across the LHD regarding implementation. An online vaccination consent form was developed and installed on the LHD network within 2 weeks. Administrative staff ensured timely entry of HCW data and vaccination status and analysis of uptake using Microsoft Excel. Results REDCap (Vanderbilt University, Nashville, TN, USA) was identified as the most appropriate web-based platform based on the ease of developing a secure and inexpensive data collection tool in a short time period. In all, 10064 employees were recorded in REDCap as having received the influenza vaccine. Customised REDCap reports allowed managers to follow up staff yet to receive their vaccination, which resulted in further vaccinations. Conclusions REDCap was successfully used as a data collection tool to track the influenza vaccination rates of staff. The data assisted the District Workforce Services in ensuring that facilities complied with NSW Health policy. This study highlights how REDCap may be used by similar organisations to monitor influenza vaccination of HCWs. What is known about the topic? There is increasing recognition of the need to ensure high-quality monitoring of HCW influenza vaccination rates, yet coverage is often difficult to measure accurately due to a lack of centralised reporting and monitoring systems. What does this paper add? This paper outlines how a computerised database (REDCap) was used by a NSW Health jurisdiction to monitor a vaccination program. REDCap is an inexpensive and easy to use system that allowed public health authorities rapid analysis of HCW vaccination coverage rates. What are the implications for practitioners? The findings add to the growing body of evidence demonstrating the utility of online systems for monitoring HCW influenza vaccinations. These results will be relevant to healthcare organisations and public health practitioners seeking quick and feasible research and data collection platforms.

Gonorrhoea enhanced surveillance for indigenous status and risk factors in the south-eastern Sydney population

Background: Gonorrhoea incidence is increasing in the Australian population. As a laboratory notifiable disease in NSW, information is not routinely available on indigenous status, sexual preference or other risk factors for infection. We conducted a 12-month pilot of enhanced surveillance in south-eastern Sydney in order to assess the feasibility of gathering this additional information. Methods: For each notification in a south-eastern Sydney resident with a 2013 specimen date, we sent a letter and questionnaire to the requesting doctor seeking additional demographic and risk factor information. Results: Of 1,341 questionnaires sent, 1,073 (79.5%) were returned, and men comprised 947 (88.3%). Indigenous status was provided for 1,009 (94.1%) cases, with seven (0.7%) identified as Aboriginal or Torres Strait Islander. Most men (83%) but a minority of women (19%) had same sex partners (p<0.001). Whilst 70% of men reported acquisition from a casual partner, only 46% of women thought they had acquired infection from a casual partner. Conclusions: The high response rate and completeness of indigenous status were strong features of this enhanced surveillance pilot which also provided valuable information on sexual preference and other risk factors for infection. However, gathering of this information was very labour intensive for both clinical and public health staff.

Children overdue for immunisation: a question of coverage or reporting? An audit of the Australian Immunisation Register.

OBJECTIVE: Vaccinations in Australia are reportable to the Australian Immunisation Register (AIR). Following major immunisation policy initiatives, the New South Wales (NSW) Public Health Network undertook an audit to estimate true immunisation coverage of NSW children at one year of age, and explore reasons associated with under-reporting. METHODS: Cross-sectional survey examining AIR immunisation records of a stratified random sample of 491 NSW children aged 12≤15 months at 30 September 2017 who were >30 days overdue for immunisation. Survey data were analysed using population weights. RESULTS: Estimated true coverage of fully vaccinated one-year-old children in NSW is 96.2% (CI:95.9-96.4), 2.1% higher than AIR reported coverage of 94.1%. Of the children reported as overdue on AIR, 34.9% (CI:30.9-38.9) were actually fully vaccinated. No significant association was found between under-reporting and socioeconomic status, rurality or reported local coverage level. Data errors in AIR uploading (at provider level) and duplicate records contributed to incorrect AIR coverage recording. CONCLUSIONS: Despite incentives to record childhood vaccinations on AIR, under-reporting continues to be an important contributor to underestimation of true coverage in NSW. Implications for public health: More reliable transmission of encounters to AIR at provider level and removal of duplicates would improve accuracy of reported coverage.