Connecting patients notified with hepatitis C to treatment (CONNECT Study): A randomized controlled trial of active case management by a health department to support primary care practitioners.

BACKGROUND: Despite subsidised access to direct-acting antivirals (DAAs), hepatitis C (HCV) treatment uptake in Australia is declining. Interventions are needed to link people living with HCV to care and treatment. We implemented and measured effectiveness of a state-wide, health department-led, enhanced case management through the primary care practitioner for all HCV notifications, aiming to encourage and support treatment commencement. METHODS: A randomised controlled trial compared enhanced case management, delivered by the health department to diagnosing clinicians, with standard of care using notifiable disease systems in Tasmania, Australia (2020-21). The intervention involved a nurse specialist contacting and providing support by telephone to primary care practitioners making an HCV notification. The primary outcome was the proportion of cases notified with chronic hepatitis C who commenced treatment within 12 weeks of notification. We allowed a 12-week extended follow-up period at the end of the study for participants with no outcomes. RESULTS: Eighty-five primary care practitioners randomised to the intervention and 86 to standard of care arms notified 111 and 115 HCV cases, respectively. The proportion of cases notified with chronic hepatitis (HCV RNA detected) commencing treatment within 12 weeks was similar between study arms (41% vs 33%; p=0·51) and after extended study follow-up (65% vs 48%; p=0·18). RNA test completion was higher in the intervention than in standard of care arm (89% vs. 78%; p=0·03), while completing pre-treatment workup for chronic patients (65% vs. 64%; p=0·93) was similar. CONCLUSION: This was the first prospective randomised study of the utility of immediate HCV notification follow-up of primary care practitioners to enhance treatment uptake using disease notification surveillance data. We demonstrated improvement in HCV RNA testing and trend toward better engagement in care, but no significant increase in treatment uptake.

Serology study of healthcare workers following a hospital-based outbreak of COVID-19 in North West Tasmania, Australia, 2020.

Introduction: Healthcare facilities are high-risk settings for coronavirus disease 2019 (COVID-19) transmission. Early in the COVID-19 pandemic, the first large healthcare-associated outbreak within Australia occurred in Tasmania. Several operational research studies were conducted amongst workers from the implicated hospital campus, to learn more about COVID-19 transmission. Methods: Healthcare workers (HCWs) from the implicated hospital campus were invited to complete an online survey and participate in a serology study. Blood samples for serological testing were collected at approximately 12 weeks (round one) and eight months (round two) after the outbreak. A descriptive analysis was conducted of participant characteristics, serology results, and longevity of antibodies. Results: There were 261 HCWs in round one, of whom 44 (17%) were polymerase chain reaction (PCR) confirmed outbreak cases; 129 of the 261 (49%) participated in round two, of whom 34 (27%) were outbreak cases. The prevalence of positive antibodies at round one was 15% (n = 38) and at round two was 12% (n = 15). There were 15 participants (12%) who were seropositive in both rounds, with a further 9% (n = 12) of round two participants having equivocal results after previously being seropositive. Six HCWs not identified as cases during the outbreak were seropositive in round one, with three still seropositive in round two. Of those who participated in both rounds, 68% (n = 88) were seronegative at both time points. Discussion: Our findings demonstrate that serological testing after this large healthcare-associated COVID-19 outbreak complemented the findings of earlier diagnostic testing, with evidence of additional infections to those diagnosed when use of PCR testing had been restricted. The results also provide evidence of persisting SARS-CoV-2 antibody response eight months after an outbreak in an unvaccinated population. The high proportion of HCWs who remained seronegative is consistent with low community transmission in Tasmania after this outbreak.

Towards tobacco-free retailers: feasibility of an intervention encouraging retailers to stop selling tobacco in Tasmania.

BACKGROUND: Despite calls for greater emphasis on tobacco supply reduction strategies, limited evidence of interventions (regulatory and non-regulatory) to reduce tobacco retailer numbers exists. This study investigated the feasibility of a real-world, non-regulatory intervention to encourage low volume tobacco retailers to stop selling, in a jurisdiction with a tobacco retailer licensing system. INTERVENTION: Between December 2018 and 2019, low volume tobacco retailers (n=164) were exposed to multiple intervention elements (eg, postcard and letter mail-out, onsite visit) focused on the business benefits of stopping selling, in the lead up to their tobacco licence expiry date. The intervention was delivered in Tasmania, Australia in a region characterised by socioeconomic disadvantage, high smoking rates and density of tobacco retailers. METHODS: For this mixed-methods study we collected data through implementation records on 164 retailers and postintervention interviews with 21 retailers to explore intervention implementation, awareness, acceptability, usefulness and actions taken. RESULTS: Retailers were able to recall the intervention, specifically messages focused on the business-related reasons to stop selling tobacco. Of the 107 retailers that the project officer spoke with onsite or via telephone, the majority (72%) accepted phase I components. The intervention introduced some retailers to the concept of ending tobacco sales, which made them stop and consider this option. Of the 164 retailers exposed to the intervention, 18 (11%) retailers ended tobacco sales. CONCLUSION: Our study suggests that a non-regulatory intervention targeting low volume retailers to end tobacco sales may help to reduce the retail availability of tobacco.

Randomised controlled trial of active case management to link hepatitis C notifications to treatment in Tasmania, Australia: a study protocol.

INTRODUCTION: By subsidising access to direct acting antivirals (DAAs) for all people living with hepatitis C (HCV) in 2016, Australia is positioned to eliminate HCV as a public health threat. However, uptake of DAAs has declined over recent years and new initiatives are needed to engage people living with HCV in care. Active follow-up of HCV notifications by the health department to the notifying general practitioner (GP) may increase treatment uptake. In this study, we explore the impact of using hepatitis C notifications systems to engage diagnosing GPs and improve patient access to treatment. METHODS AND ANALYSIS: This study is a randomised controlled trial comparing enhanced case management of HCV notifications with standard of care. The intervention includes phone calls from a department of health (DoH) specialist HCV nurse to notifying GPs and offering HCV management support. The level of support requested by the GP was graded in complexity: level 1: HCV information only; level 2: follow-up testing advice; level 3: prescription support including linkage to specialist clinicians and level 4: direct patient contact. The study population includes all GPs in Tasmania who notified HCV diagnosis to the DoH between September 2020 and December 2021. The primary outcome is proportion of HCV cases who initiate DAAs after 12 weeks of HCV notification to the health department. Secondary outcomes are proportion of HCV notifications that complete HCV RNA testing, treatment workup and treatment completion. Multiple logistic regression modelling will explore factors associated with the primary and secondary outcomes. The sample size required to detect a significant difference for the primary outcome is 85 GPs in each arm with a two-sided alpha of 0.05% and 80% power. ETHICS AND DISSEMINATION: The study was approved by University of Tasmania's Human Research Ethics Committee (Protocol ID: 18418) on 17 December 2019. Results of the project will be presented in scientific meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04510246. TRIAL PROGRESSION: The study commenced recruitment in September 2020 and end of study expected December 2021.

School-Level Variation in Coverage of Co-Administered dTpa and HPV Dose 1 in Three Australian States.

BACKGROUND: Australian adolescents are routinely offered HPV and dTpa (diphtheria, tetanus, pertussis) vaccines simultaneously in the secondary school vaccination program. We identified schools where HPV initiation was lower than dTpa coverage and associated school-level factors across three states. METHODS: HPV vaccination initiation rates and dTpa vaccination coverage in 2016 were calculated using vaccine databases and school enrolment data. A multivariate analysis assessed sociodemographic and school-level factors associated with HPV initiation being >5% absolute lower than dTpa coverage. RESULTS: Of 1280 schools included, the median school-level HPV initiation rate was 85% (interquartile range (IQR):75-90%) and the median dTpa coverage was 86% (IQR:75-92%). Nearly a quarter (24%) of all schools had HPV vaccination initiation >5% lower than dTpa coverage and 11 % had >10% difference. School-level factors independently associated with >5% difference were remote schools (aOR:3.5, 95% CI = 1.7-7.2) and schools in major cities (aOR:1.8, 95% CI = 1.0-3.0), small schools (aOR:3.3, 95% CI = 2.3-5.7), higher socioeconomic advantage (aOR:1.7, 95% CI = 1.1-2.6), and lower proportions of Language-background-other-than-English (aOR:1.9, 95% CI = 1.2-3.0). CONCLUSION: The results identified a quarter of schools had lower HPV than dTpa initiation coverage, which may indicate HPV vaccine hesitancy, and the difference was more likely in socioeconomically advantaged schools. As hesitancy is context specific, it is important to understand the potential drivers of hesitancy and future research needs to understand the reasons driving differential uptake.

Lessons learnt from the first large outbreak of COVID-19 in health-care settings in Tasmania, Australia.

PROBLEM: One month after the initial case of coronavirus disease 2019 (COVID-19) in Tasmania, an island state of Australia, two health-care workers (HCWs) from a single regional hospital were notified to public health authorities following positive tests for SARS-CoV-2 nucleic acid. These were the first recognized cases in an outbreak that overwhelmed the hospital's ability to function. CONTEXT: The outbreak originated from two index cases. Both had returned to Tasmania following travel on a cruise ship and required hospital admission for management of COVID-19. A total of 138 cases were subsequently linked to this outbreak: 81 HCWs (most being nurses) and 23 patients across three hospitals, one resident of an aged-care facility and 33 close contacts. ACTION: The outbreak was controlled through the identification and isolation of cases, identification and quarantining of close contacts and their household members, closure of the affected facilities and community-level restrictions to reduce social mixing in the affected region. LESSONS LEARNT: Factors that were likely to have contributed to ongoing transmission in this setting included workplace practices that prevented adequate physical distancing, attending work while symptomatic, challenges in rapidly identifying contacts, mobility of staff and patients between facilities, and challenges in the implementation of infection control practices. DISCUSSION: Many commonly accepted hospital practices before the COVID-19 pandemic amplified the outbreak. The lessons learnt from this investigation changed work practices for HCWs and led to wider public health interventions in the management of potential primary and secondary contacts.

COVID-19: Integrating genomic and epidemiological data to inform public health interventions and policy in Tasmania, Australia.

OBJECTIVE: We undertook an integrated analysis of genomic and epidemiological data to investigate a large health-care-associated outbreak of coronavirus disease 2019 (COVID-19) and to better understand the epidemiology of COVID-19 cases in Tasmania, Australia. METHODS: Epidemiological data collected on COVID-19 cases notified in Tasmania between 2 March and 15 May 2020, and positive samples of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or RNA extracted from the samples were included. Sequencing was conducted by tiled amplicon polymerase chain reaction with ARTIC v1 or v3 primers and Illumina sequencing. Consensus sequences were generated, sequences were aligned to a reference sequence and phylogenetic analysis was performed. Genomic clusters were determined and integrated with epidemiological data to provide additional information. RESULTS: All 231 COVID-19 cases notified in Tasmania during the study period and 266 SARS-CoV-2-positive samples, representing 217/231 (94%) notified cases, were included; 184/217 (84%) were clustered, 21/217 (10%) were unique and 12/217 (6%) could not be sequenced. Genomics confirmed the presence of seven clusters already identified through epidemiological links, clarified transmission networks in which the epidemiology had been unclear and identified one cluster that had not previously been recognized. DISCUSSION: Genomic analysis provided useful additional information on COVID-19 in Tasmania, including evidence of a large health-care-associated outbreak linked to an overseas cruise, the probable source of infection in cases with no previously identified epidemiological link and confirmation that there was no identified community transmission from other imported cases. Genomic insights are an important component of the response to COVID-19, and continuing genomic surveillance is warranted.

Why Tasmanian retailers stop selling tobacco and implications for tobacco control.

INTRODUCTION: The retail availability of tobacco is at odds with the health harms associated with tobacco smoking and undermines tobacco control efforts. Evidence suggests ease of access to tobacco through retail outlets contributes to smoking prevalence. OBJECTIVE: This study aimed to understand why retailers stop selling tobacco and explore possible implications for tobacco control. METHODS: The Tobacco Licensing Database maintained by the Department of Health Tasmania was used to identify and recruit past retailers who no longer held licences. Semistructured interviews were conducted to explore business demographics and the reasons they stopped selling tobacco. Interview findings were analysed using a thematic framework. RESULTS: Twenty former tobacco retailers participated, representing all business types except specialist tobacconists and large supermarkets. Retailers gave multiple reasons for ending tobacco sales, related to business considerations, security, tobacco regulations, ethics and health. Most often, the decision was business-related; health or ethical considerations were rarely a factor. Most retailers felt they played no role in mitigating tobacco-related harm. CONCLUSIONS: This study provides insights into factors that make tobacco sales unattractive or unfeasible for low-volume outlets and may inform supply-focused tobacco control policy. A campaign that emphasises the possible business benefits of ending tobacco sales in favour of other higher-margin products may support retailers to transition away from tobacco sales. The regulatory obligations of selling tobacco are disincentives and create a less favourable retail environment.

Public Health Messaging During Extreme Smoke Events: Are We Hitting the Mark?

Background: Emergency services working to protect communities from harm during wildfires aim to provide regular public advisories on the hazards from fire and smoke. However, there are few studies evaluating the success of public health communications regarding the management of smoke exposure. We explored the responses to smoke-related health advisories of people living in a severely smoke-affected region during extensive wildfires in Tasmania, Australia early in 2019. We also evaluated the acceptability of portable high efficiency particle air (HEPA) cleaners used in study participant's homes during the smoky period. Methods: We conducted semi-structured interviews with 24 households in the Huon Valley region of Tasmania following a severe smoke episode. These households were initially recruited into a HEPA cleaner study. Interviews were recorded, transcribed, and analyzed for common themes using an inductive framework approach. Results: Public health messaging during the 2019 wildfire event in Tasmania was widely shared and understood, with social media playing a central role. However, some participants expressed concerns about the timeliness and effectiveness of the recommended interventions, and some would have appreciated more detailed information about the health risks from smoke. Public messages and actions to protect households from wildfire threat were, at times, contradictory or dominated in coverage over the smoke messaging, and many participants were conflicted with the multiple public messages and action relating to the more serious perceived threat from the fire. Conclusions: Public messaging about smoke and health should continue to use multiple avenues of communication, with a focus on simple messages provided through social media. Messaging about the smoke hazard should be available from a trusted central source regarding all aspects of the wildfire emergency, with links to more detailed information including local air quality data alongside interpretation of the associated health risks.

Whole-Genome Sequencing of Salmonella Mississippi and Typhimurium Definitive Type 160, Australia and New Zealand.

We used phylogenomic and risk factor data on isolates of Salmonella enterica serovars Mississippi and Typhimurium definitive type 160 (DT160) collected from human, animal, and environmental sources to elucidate their epidemiology and disease reservoirs in Australia and New Zealand. Sequence data suggested wild birds as a likely reservoir for DT160; animal and environmental sources varied more for Salmonella Mississippi than for Salmonella Typhimurium. Australia and New Zealand isolates sat in distinct clades for both serovars; the median single-nucleotide polymorphism distance for DT160 was 29 (range 8-66) and for Salmonella Mississippi, 619 (range 565-737). Phylogenomic data identified plausible sources of human infection from wildlife and environmental reservoirs and provided evidence supporting New Zealand-acquired DT160 in a group of travelers returning to Australia. Wider use of real-time whole-genome sequencing in new locations and for other serovars may identify sources and routes of transmission, thereby aiding prevention and control.

New and old hotspots for rickettsial spotted fever acquired in Tasmania, 2012-2017.

OBJECTIVE: To describe the epidemiology and clinical characteristics of Tasmania-acquired rickettsial disease notified to the Department of Health in Tasmania from 2012 to 2017 inclusive. METHODS: Data on rickettsiosis cases acquired and notified in Tasmania between 1 January 2012 and 31 December 2017 were analysed descriptively. RESULTS: Eighteen cases of rickettsial infection notified in Tasmania 2012-17 and likely acquired in the state met one of three case definitions: 12 confirmed (67%), four probable (22%), and two possible (11%). The mean number of cases per year was 3.0 (population rate 0.6 per 100,000 population/year); 60% of cases occurred in November and December. Cases were more commonly older males. Fever, lethargy, and rash were commonly reported symptoms. Thirteen cases were likely acquired on Flinders Island, three around Great Oyster Bay and two in the Midlands. CONCLUSIONS: This study extends our knowledge of the epidemiology of rickettsial disease in Tasmania. This is the first account including confirmed cases acquired in the Midlands of Tasmania. Implications for public health: Increased knowledge and awareness of epidemiology of rickettsial infection in Tasmania is essential for timely diagnosis and appropriate treatment. These findings bear wider relevance outside Tasmania because visitors may also be at risk.

The retail availability of tobacco in Tasmania: evidence for a socio-economic and geographical gradient.

OBJECTIVES: To describe the retail availability of tobacco and to examine the association between tobacco outlet density and area-level remoteness and socio-economic status classification in Tasmania. DESIGN: Ecological cross-sectional study; analysis of tobacco retail outlet data collected by the Department of Health and Human Services (Tasmania) according to area-level (Statistical Areas Level 2) remoteness (defined by the Remoteness Structure of the Australian Statistical Geographical Standard) and socio-economic status (defined by the 2011 Australian Bureau of Statistics Index of Relative Socioeconomic Advantage and Disadvantage). MAIN OUTCOME MEASURE: Tobacco retail outlet density per 1000 residents. RESULTS: On 31 December 2016, there were 1.54 tobacco retail outlets per 1000 persons. The density of outlets was 79% greater in suburbs or towns in outer regional, remote and very remote Tasmania than in inner regional Tasmania (rate ratio [RR], 1.79; 95% confidence Interval [CI], 1.29-2.50; P < 0.001). Suburbs or towns in Tasmania with the greatest socio-economic disadvantage had more than twice the number of tobacco outlets per 1000 people as areas of least disadvantage (RR, 2.30; 95% CI, 1.32-4.21; P = 0.014). CONCLUSIONS: A disproportionate concentration of tobacco retail outlets in regional and remote Tasmania and in areas of lowest socio-economic status is evident. Our findings are consistent with those of analyses in New South Wales and Western Australia. Progressive tobacco retail restrictions have been proposed as the next frontier in tobacco control. However, the intended and unintended consequences of such policies need to be investigated, particularly for socio-economically deprived and rural areas.

An Outbreak of Paralytic Shellfish Poisoning in Tasmania.

Paralytic shellfish poisoning (PSP) is a rare illness caused by eating shellfish containing paralytic shellfish toxins (PST). Toxins are produced during harmful algal blooms, which occur most years on the east coast of Tasmania. Contaminated seafood looks and tastes normal and toxins are not destroyed by cooking or freezing. Commercial shellfish farms are monitored for harmful algae and shellfish toxins, but wild shellfish are not and pose a potential public health risk. A case of PSP was documented in Tasmania in 2011, and we are aware of anecdotal reports of cases in the 1980s and 1990s. We are not aware of cases elsewhere in Australia but harmful algal blooms have been detected in Victoria, South Australia and New South Wales. Routine monitoring of commercial shellfish in 2015 detected a large bloom of Alexandrium tamarense on the east coast of Tasmania, which can cause PSP. Between 2 and 12 October 2015, four cases of PSP were identified. All were adults who ate wild mussels from the east coast of Tasmania and had onset of numbness or tingling of the face and muscle weakness from 30 minutes to 12 hours later. Two cases were briefly hospitalised, both recovered. Since the outbreak, permanent signage at locations where shellfish are frequently recreationally foraged has been erected. Additional alerts are released during high risk periods based on surveillance of commercial sites by the Tasmanian Shellfish Quality Assurance Program. Several states in Australia are at risk of cases of PSP. We recommend active surveillance and multi-jurisdictional collaboration to manage this risk.

Increasing Antimicrobial Resistance in Nontyphoidal Salmonella Isolates in Australia from 1979 to 2015.

Australia has high and increasing rates of salmonellosis. To date, the serovar distribution and associated antimicrobial resistance (AMR) patterns of nontyphoidal Salmonella enterica (NTS) in Australia have not been assessed. Such information provides critical knowledge about AMR in the food chain and informs decisions about public health. We reviewed longitudinal data on NTS in two Australian states over a 37-year period, between 1979 and 2015, and antimicrobial resistance since 1984. Overall, 17% of isolates were nonsusceptible to at least one antimicrobial, 4.9% were nonsusceptible to ciprofloxacin, and 0.6% were nonsusceptible to cefotaxime. In total, 2.5% of isolates were from invasive infections, with no significant difference in AMR profiles between invasive and noninvasive isolates. Most isolates with clinically relevant AMR profiles were associated with travel, particularly to Southeast Asia, with multiple "incursions" of virulent and resistant clones into Australia. Our findings represent the largest longitudinal surveillance system for NTS in Australia and provide valuable public health knowledge on the trends and distribution of AMR in NTS. Ongoing surveillance is critical to identify local emergence of resistant isolates.

A novel public health threat - high lead solder in stainless steel rainwater tanks in Tasmania.

OBJECTIVE: We identified two water tanks in Tasmania with water lead concentrations exceeding the Australian Drinking Water Guidelines (ADWG) limit; they had been constructed with stainless steel and high-lead solder from a single manufacturer. An investigation was initiated to identify all tanks constructed by this manufacturer and prevent further exposure to contaminated water. METHODS: To identify water tanks we used sales accounts, blood and water lead results from laboratories, and media. We analysed blood and water lead concentration results from laboratories and conducted a nested cohort study of blood lead concentrations in children aged <18 years. RESULTS: We identifed 144 tanks constructed from stainless steel and high lead solder. Median water lead concentrations were significantly higher in the stainless steel tanks (121µg/L) than in the galvanised tanks (1µg/L). Blood lead concentrations ranged from 1 to 26µg/dL (median 5µg/dL); of these, 77% (n=50) were below the then-recommended health-related concentration of 10µg/dL. Concentrations in the 15 people (23%) above this limit ranged from 10-26µg/dL, with a median of 14µg/dL. The median blood lead concentration in the nested cohort of children was initially 8.5µg/dL, dropping to 4.5µg/dL after follow-up. CONCLUSIONS: Lead concentrations in the water tanks constructed from stainless steel and high-lead solder were up to 200 times above the recommended ADWG limits. Implications for public health: This investigation highlights the public health risk posed by use of non-compliant materials in constructing water tanks.

Increasing Incidence of Salmonella in Australia, 2000-2013.

Salmonella is a key cause of foodborne gastroenteritis in Australia and case numbers are increasing. We used negative binomial regression to analyze national surveillance data for 2000-2013, for Salmonella Typhimurium and non-Typhimurium Salmonella serovars. We estimated incidence rate ratios adjusted for sex and age to show trends over time. Almost all states and territories had significantly increasing trends of reported infection for S. Typhimurium, with states and territories reporting annual increases as high as 12% (95% confidence interval 10-14%) for S. Typhimurium in the Australian Capital Territory and 6% (95% CI 5-7%) for non-Typhimurium Salmonella in Victoria. S. Typhimurium notification rates were higher than non-Typhimurium Salmonella rates in most age groups in the south eastern states of Australia, while non-Typhimurium rates were higher in most age groups elsewhere. The S. Typhimurium notification rate peaked at 12-23 months of age and the non-Typhimurium Salmonella notification rate peaked at 0-11 months of age. The age-specific pattern of S. Typhimurium cases suggests a foodborne origin, while the age and geographic pattern for non-Typhimurium may indicate that other transmission routes play a key role for these serovars.

An outbreak of norovirus linked to oysters in Tasmania.

Norovirus is the most commonly reported virus in shellfish related gastroenteritis outbreaks. In March 2013 an investigation was conducted following the receipt of reports of gastroenteritis after the consumption of oysters at private functions in Tasmania. Cases were ascertained through general practitioners, emergency departments, media releases and self-reporting. Of the 306 cases identified in Tasmania, ten faecal specimens were collected for laboratory testing and eight were positive for norovirus (GII.g). The most common symptoms were vomiting (87%), diarrhoea (85%), myalgia (82%) and fever (56%). The implicated oysters were traced to a single lease from which they were harvested and distributed locally and interstate. Nationally 525 cases were identified from Tasmania (306), Victoria (209), New South Wales (8) and Queensland (2). This report highlights the consequences of norovirus outbreaks in shellfish, even with rapid identification, trace back and removal of the implicated product from the market.

Proportion of illness acquired by foodborne transmission for nine enteric pathogens in Australia: an expert elicitation.

BACKGROUND: Estimates of the burden of illness acquired from food inform public health policy and prioritize interventions. A key component of such estimates is the proportion of illnesses that are acquired by foodborne transmission. In view of the shortage of requisite data, these proportions are commonly obtained through a process known as expert elicitation. We report findings from an elicitation process used to assess the importance of the foodborne transmission route for nine pathogens in Australia, circa 2010. MATERIALS AND METHODS: Eleven experts were asked to estimate the proportion of illness acquired by five transmission routes: food, environmental, water, person, and zoonotic, together with a 90% certainty interval for foodborne transmission. Foodborne estimates and intervals from each expert were combined using both modified triangular and Program Evaluation and Review Technique (PERT) distributions, in @Risk version 6, to generate final distributions from which median estimates and 95% Credible Intervals (CrI) were calculated. RESULTS: Shiga toxin-producing Escherichia coli (STEC) was the only pathogen believed to have an important zoonotic transmission route, while norovirus, hepatitis A virus, non-STEC pathogenic E. coli, and Shigella spp. were all thought to be primarily spread from person to person. Foodborne transmission was the main route for Clostridium perfringens (98%, CrI: 84-100), Listeria monocytogenes (98%, CrI: 86-100), nontyphoidal Salmonella spp. (72%, CrI: 50-87), and Campylobacter spp. (77%, CrI: 60-90). Foodborne estimates using the modified triangular distribution had wider CrI than these calculated using the PERT distribution. CONCLUSIONS: Foodborne proportions for most pathogens in this study were the same or lower than those estimated circa 2000 in Australia, with the greatest decline for non-STEC pathogenic E. coli. Inclusion of certainty intervals from experts helps to quantify the precision of foodborne proportions. A decline in estimates of the foodborne proportion for common pathogens will influence final estimates of the burden of illness acquired from food.

Surveillance for outbreaks of gastroenteritis in long-term care facilities, Australia, 2002-2008.

BACKGROUND: Each year in Australia, health departments investigate hundreds of gastroenteritis outbreaks. Long-term care facilities (LTCFs) for elderly persons are a common setting for these outbreaks and can result in potentially serious outcomes. METHODS: We established surveillance for gastroenteritis outbreaks in 2001, and analyzed data on outbreaks occurring from 1 July 2002 through 30 June 2008 to estimate the incidence in Australian LTCFs and residents. We summarized outbreaks by mode of transmission and etiological agent. We used negative binomial regression to examine variation in the number of fecal specimens collected in outbreaks-a marker of investigation intensity. RESULTS: During surveillance, 3257 (52%) of 6295 outbreaks of gastroenteritis and foodborne disease in Australia were reported in LTCFs. These outbreaks affected 84,769 people, with 1577 people hospitalized and 209 deaths. There were 0.19 (95% confidence interval, 0.14-0.26) residents affected per 1000 bed days and 16.8 (95% confidence interval, 12.4-22.7) outbreaks per 100 LTCFs annually. LTCF outbreaks were most commonly transmitted from person to person. Only 43 (1.3% ) of 3257 outbreaks were foodborne, although 47 (6.4%) of 733 residents were hospitalized and 20 (2.7%) of 733 died. Norovirus was responsible for 1136 (35%) of all 3257 outbreaks. Higher numbers of fecal specimens per outbreak were collected in 4 Australian States, in later years of surveillance, and where the etiology was identified. CONCLUSIONS: Norovirus outbreaks spread from person to person are common in LTCFs, although clinicians should be alert for foodborne outbreaks with more serious consequences. There is a need to identify effective infection control measures to assist facilities in managing outbreaks of gastroenteritis.