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.

A Cross-Sectional Study of Measles-Specific Antibody Levels in Australian Blood Donors-Implications for Measles Post-Elimination Countries.

Passive immunisation with normal human immunoglobulin (NHIG) is recommended as post-exposure prophylaxis (PEP) for higher-risk measles contacts where vaccination is contraindicated. However, the concentration of measles-specific antibodies in NHIG depends on antibody levels within pooled donor plasma. There are concerns that measles immunity in the Australian population may be declining over time and that blood donors' levels will progressively decrease, impacting levels required to produce effective NHIG for measles PEP. A cross-sectional study of Australian plasmapheresis donors was performed using an age-stratified, random sample of recovered serum specimens, collected between October and November 2019 (n = 1199). Measles-specific IgG antibodies were quantified by ELISA (Enzygnost anti-measles virus IgG, Siemens), and negative and equivocal specimens (n = 149) also underwent plaque reduction neutralisation testing (PRNT). Mean antibody levels (optical density values) progressively decreased from older to younger birth cohorts, from 2.09 [±0.09, 95% CI] to 0.58 [±0.04, 95% CI] in donors born in 1940-1959 and 1990-2001, respectively (p < 0.0001). This study shows that mean measles-specific IgG levels are significantly lower in younger Australian donors. While current NHIG selection policies target older donors, as younger birth cohorts become an increasingly larger proportion of contributing donors, measles-specific antibody concentrations of NHIG will progressively reduce. We therefore recommend monitoring measles-specific antibody levels in future donors and NHIG products in Australia and other countries that eliminated measles before the birth of their youngest blood donors.

Epidemiology of Group A Streptococcal bacteraemia in Hunter New England Local Health District, 2008 to 2019.

Invasive Group A Streptococcal infection (iGAS) is an uncommon but serious infection with Streptococcus pyogenes in a normally sterile body site. Manifestations include bacteraemia, necrotising fasciitis and toxic shock syndrome with attendant serious morbidity and mortality. An increasing incidence of iGAS has been observed in some regions of Australia. iGAS became a nationally notifiable condition from 1 July 2021. To determine if regional incidence has increased, and to identify priority populations, we undertook a retrospective data analysis of Group A Streptococcal (GAS) bacteraemia cases in Hunter New England Local Health District (HNELHD), New South Wales, Australia, from 1 January 2008 to 31 December 2019, as identified by NSW Health Pathology, John Hunter Hospital. A total of 486 cases were identified (age-standardised rate: 4.05 cases per 100,000 population per year). Incidence in HNELHD gradually increased over the study period (adjusted incidence rate ratio: 1.04; 95% confidence interval: 1.01-1.07) and was significantly higher in children under 5 years of age; in adults over 70 years of age; in males; and in First Nations peoples. A significant peak occurred in 2017 (9.00 cases per 100,000 population), the cause of which remains unclear. GAS bacteraemia is uncommon but severe, and incidence in HNELHD has slowly increased. Public health and clinical guidelines must address the needs of priority populations, which include young children, older adults and First Nations peoples. Routine surveillance and genomic analysis will help improve our understanding of iGAS and inform best public health management.

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.

Australian general practitioner chlamydia testing rates among young people.

OBJECTIVE: To describe the proportion of 16-29-year-olds tested for chlamydia by Australian general practitioners in a 12-month period. DESIGN AND SETTING: Between October 2007 and September 2008, the national chlamydia testing rate in 16-29-year-olds was calculated by dividing the number of Medicare-reimbursed chlamydia tests by two denominators: (i) Medicare-reimbursed GP consultations; and (ii) estimated resident populations adjusted for the proportion who were sexually active. MAIN OUTCOME MEASURES: GP chlamydia testing rates in 16-29-year-olds per 100 patients attending a GP consultation and per 100 sexually active population, by patient age and sex, state/territory of residence, and remoteness area. RESULTS: Among the estimated Australian population of 16-29-year-olds, 85.6% of females and 64.4% of males had at least one GP consultation in the 12-month period. The national GP chlamydia testing rate per 100 patients was 8.9% (95% CI, 8.88%-8.94%). The national GP chlamydia testing rate per 100 sexually active population was 8.0% (95% CI, 7.92%-7.98%). The rate per 100 sexually active population was higher in females (12.5%) compared with males (3.7%) (P < 0.01); higher in 20-24-year-olds (9.0%) compared with 16-19-year-olds (8.7%) and 25-29-year-olds (6.6%) (P < 0.01); higher in those living in non-metropolitan areas (11.0%) compared with metropolitan areas (8.4%) (P < 0.01); and highest in those living in the Northern Territory (21.4%) compared with other jurisdictions (P < 0.01). CONCLUSIONS: Despite clinical guidelines recommending annual chlamydia testing for sexually active 15-29-year-olds, our analysis showed that a high proportion of young people aged 16-29 years attend a GP each year, but few of the sexually active population in this age group were tested for chlamydia in general practice. Strategies are needed to support GPs to enhance chlamydia testing in young people.

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.

Supply system factors associated with microbiological drinking water safety in regional New South Wales, Australia, 2001-2007.

AIM: To determine factors associated with microbiological safety of public drinking water systems in regional New South Wales (NSW), Australia. METHOD: We analysed 107,000 end-user drinking water samples for an association between detection of Escherichia coli and drinking water system features, sample year and season using NSW Health Drinking Water Monitoring Program data, 2001-2007. We used negative binomial generalized estimating equations with adjustment for autocorrelation and clustering. RESULTS: We detected E. coli in over 2% of samples from 40% (129/323) of systems. E. coli detection was significantly more common in earlier years and during summer (p<0.001). On multivariate analysis E. coli detection was significantly associated with smaller systems; watercourse sources; no disinfection or disinfection with ultraviolet only; and higher post-treatment mean turbidity (all p< or =0.01). Detection was most strongly associated with lack of disinfection (incidence rate ratio 12.6, p<0.001) and smaller supply systems (1% reduction in E. coli detection for each 1,000 person increase in supply population, p=0.004). Ultraviolet disinfection alone was the least effective disinfection method (p<0.001). CONCLUSION: Even in developed countries, drinking water systems without disinfection or serving small populations appear vulnerable to the effects of faecal contamination, which presents a risk of waterborne disease outbreaks.

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.

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.

Challenges in using serological methods to explore historical transmission risk of Chlamydia psittaci in a workforce with high exposure to equine chlamydiosis.

Introduction: This report describes the challenges encountered in using serological methods to study the historical transmission risk of C. psittaci from horses to humans. Methods: In 2017, serology and risk factor questionnaire data from a group of individuals, whose occupations involved close contact with horses, were collected to assess the seroprevalence of antibodies to C. psittaci and identify risk factors associated with previous exposure. Results: 147 participants were enrolled in the study, provided blood samples, and completed a questionnaire. On ELISA testing, antibodies to the Chlamydia genus were detected in samples from 17 participants but further specific species-specific MIF testing did not detect C. psittaci-specific antibodies in any of these samples. Conclusion: No serological evidence of past C. psittaci transmission from horses to humans was found in this study cohort. There are major challenges in using serological methods to determine the prevalence of C. psittaci exposure.

Lessons from the first 6 years of an intervention-based field epidemiology training programme in Papua New Guinea, 2013-2018.

Papua New Guinea (PNG) faces a critical shortage of human resources to address pressing public health challenges arising from an increasing burden of communicable and non-communicable diseases. PNG is an independent State in the Pacific and home to 8.2 million people. Resource and infrastructure constraints due to the country's challenging geography have made it difficult and expensive to deliver health services and implement health programmes. The National Department of Health and its partners developed a field epidemiology training programme of Papua New Guinea (FETPNG) to strengthen the country's public health workforce. The training programme covers field epidemiology competencies and includes the design, implementation and evaluation of evidence-based interventions by Fellows. From 2013 to 2018, FETPNG graduated 81 field epidemiologists. Most FETPNG graduates (84%) were from provincial or district health departments or organisations. Many of their intervention projects resulted in successful public health outcomes with tangible local impacts. Health challenges addressed included reducing the burden of multi-drug resistant-tuberculosis (TB), increasing immunisation coverage, screening and treating HIV/TB patients, and improving reproductive health outcomes. FETPNG Fellows and graduates have also evaluated disease surveillance systems and investigated disease outbreaks. Early and unwavering national ownership of FETPNG created a sustainable programme fitting the needs of this low-resource country. A focus on designing and implementing effective public health interventions not only provides useful skills to Fellows but also contributes to real-time, tangible and meaningful improvements in the health of the population. The graduates of FETPNG now provide a critical mass of public health practitioners across the country. Their skills in responding to outbreaks and public health emergencies, in collecting, analysing and interpreting data, and in designing, implementing and evaluating public health interventions continues to advance public health in PNG.

Identifying pneumonia outbreaks of public health importance: can emergency department data assist in earlier identification?

OBJECTIVE: To retrospectively review the performance of a near real-time Emergency Department (ED) Syndromic Surveillance System operating in New South Wales for identifying pneumonia outbreaks of public health importance. METHODS: Retrospective data was obtained from the NSW Emergency Department data collection for a rural hospital that has experienced a cluster of pneumonia diagnoses among teenage males in August 2006. ED standard reports were examined for signals in the overall count for each respiratory syndrome, and for elevated counts in individual subgroups including; age, sex and admission to hospital status. RESULTS: Using the current thresholds, the ED syndromic surveillance system would have trigged a signal for pneumonia syndrome in children aged 5-16 years four days earlier than the notification by a paediatrician and this signal was maintained for 14 days. CONCLUSION: If the ED syndromic surveillance system had been operating it could have identified the outbreak earlier than the paediatrician's notification. This may have permitted an earlier public health response. IMPLICATIONS: By understanding the behaviour of syndromes during outbreaks of public health importance, response protocols could be developed to facilitate earlier implementation of control measures.

Household disaster preparedness and information sources: Rapid cluster survey after a storm in New South Wales, Australia.

BACKGROUND: A storm-related disaster in New South Wales, Australia in June 2007 caused infrastructure damage, interrupted essential services, and presented major public health risks. We investigated household disaster preparedness and information sources used before and during the disaster. METHODS: Rapid cluster survey of 320 randomly selected households in Newcastle and Lake Macquarie, New South Wales, Australia. RESULTS: 227 households (71%) responded to the survey. By the day before the storm, 48% (95%CI 40-57%) of households were aware of a storm warning, principally through television (67%; 58-75%) and radio (57%; 49-66%) announcements. Storm preparations were made by 42% (28-56%) of these households.Storm information sources included: radio (78%; 68-88%); family, friends, colleagues and neighbours (50%; 40-60%); and television (41%; 30-52%). Radio was considered more useful than television (62%; 51-73% vs. 29%; 18-40%), even in households where electricity supply was uninterrupted (52%; 31-73% vs. 41%; 20-63%). Only 23% (16-30%) of households were aware that the local government-operated radio network has a designated communication role during disasters. A battery-operated household radio and appropriate batteries were available in 42% (34-50%) of households, while only 23% (16-29%) had all of: a torch, battery-operated radio, appropriate batteries, mobile phone, emergency contact list and first aid equipment. CONCLUSION: Broadcast media are important information sources immediately before and during disasters. Health services should promote awareness of broadcast networks' disaster role, especially the role of radio, and encourage general household disaster preparedness. A rapid cluster survey conducted shortly after a natural disaster provided practical, robust information for disaster planning.

Sexual health care for sex workers.

BACKGROUND: The Australian STI Prevention Framework identifies sex workers as a priority group. The Hunter New England Sexual Health Unit, based at the Royal Newcastle Hospital (New South Wales) provides free sexual health care to sex industry workers. OBJECTIVE: To assess current service delivery and barriers to accessing sexual health care by registered brothel based sex industry workers in the Hunter New England area. METHOD: An on site survey of 36 sex industry workers was conducted. RESULTS: Seventy-four percent of participants sought sexual health advice from a general practitioner compared to 37% from the sexual health unit. Seventy-seven percent of participants reported having their sexual health screening carried out according to guidelines. The most frequently stated reason for not using the sexual health unit was the inconvenience of clinic opening times. DISCUSSION: This study highlights the important role that GPs play in providing sexual health care to sex industry workers. It provides the impetus for future research, education and strategies to improve health service delivery to this important group of patients.

Multidisciplinary analysis of invasive meningococcal disease as a framework for continuous quality and safety improvement in regional Australia.

BACKGROUND: System factors in a regional Australian health district contributed to avoidable care deviations from invasive meningococcal disease (IMD) management guidelines. Traditional root cause analysis (RCA) is not well-suited to IMD, focusing on individual cases rather than system improvements. As IMD requires complex care across healthcare silos, it presents an opportunity to explore and address system-based patient safety issues. CONTEXT: Baseline assessment of IMD cases (2005-2006) identified inadequate triage, lack of senior clinician review, inconsistent vital sign recording and laboratory delays as common issues, resulting in antibiotic administration delays and inappropriate or premature discharge. METHODS: Clinical governance, in partnership with clinical and public health services, established a multidisciplinary Meningococcal Reference Group (MRG) to routinely review management of all IMD cases. The MRG comprised representatives from primary care, acute care, public health, laboratory medicine and clinical governance. Baseline data were compared with two subsequent evaluation points (2011-2012 and 2013-2015). INTERVENTIONS: Phase I involved multidisciplinary process mapping and development of a standardised audit tool from national IMD management guidelines. Phase II involved formalisation of group processes and advocacy for operational change. Phase III focused on dissemination of findings to clinicians and managers. RESULTS: Greatest care improvements were observed in the final evaluation. Median antibiotic delay decreased from 72 to 42 min and proportion of cases triaged appropriately improved from 38% to 75% between 2013 and 2015. Increasing fatal outcomes were attributed to the emergence of more virulent meningococcal serotypes. CONCLUSIONS: The MRG was a key mechanism for identifying system gaps, advocating for change and enhancing communication and coordination across services. Employing IMD case review as a focus for district-level process reflection presents an innovative patient safety approach, combining the strengths of prospective hazard analysis with more traditional RCA methodologies.

Australian bat lyssavirus

BACKGROUND: Australian bat lyssavirus (ABLV) causes human illness that is indistinguishable from classical rabies. All Australian bats have the potential to carry and transmit ABLV, and potentially risky human exposures to bats are common. ABLV infection has resulted in three human deaths in Australia since 1996. OBJECTIVE: The aim of this article is to equip general practitioners (GPs) to assist in the prevention and management of potential ABLV exposures in Australia, including complex clinical scenarios that are not fully addressed in current national guidelines. DISCUSSION: Potential ABLV exposures are frequently encountered in general practice. GPs play a critical role in risk mitigation for groups such as veterinarians and wildlife carers, and in triggering urgent multidisciplinary responses to potential exposures. Timely notification of the public health unit following a potential exposure is crucial to ensure appropriate assessment and access to correct treatment. Complex exposure scenarios require careful consideration.

Lessons learnt from a three-year pilot field epidemiology training programme.

PROBLEM: The Pacific region has widely dispersed populations, limited financial and human resources and a high burden of disease. There is an urgent need to improve the availability, reliability and timeliness of useable health data. CONTEXT: The purpose of this paper is to share lessons learnt from a three-year pilot field epidemiology training programme that was designed to respond to these Pacific health challenges. The pilot programme built on and further developed an existing field epidemiology training programme for Pacific health staff. ACTION: The programme was delivered in country by epidemiologists working for Pacific Public Health Surveillance Network partners. The programme consisted of five courses: four one-week classroom-based courses and one field epidemiology project. Sessions were structured so that theoretical understanding was achieved through interaction and reinforced through practical hands-on group activities, case studies and other interactive practical learning methods. OUTCOME: As of September 2016, 258 students had commenced the programme. Twenty-six course workshops were delivered and one cohort of students had completed the full five-course programme. The programme proved popular and gained a high level of student engagement. DISCUSSION: Face-to-face delivery, a low student-to-facilitator ratio, substantial group work and practical exercises were identified as key factors that contributed to the students developing skills and confidence. Close engagement of leaders and the need to quickly evaluate and adapt the curriculum were important lessons, and the collaboration between external partners was considered important for promoting a harmonized approach to health needs in the Pacific.