Lessons from a COVID-19 outbreak in the disability support sector, Australian Capital Territory, August 2021

Abstract

People with disability are at higher risk of severe outcomes from SARS-CoV-2 infection. Due to complex client needs and available staffing, disability support providers (DSP) were limited in their ability to mitigate the introduction of SARS-CoV-2 into disability support settings. This report describes the characteristics of a Delta variant outbreak associated with a single DSP in Canberra, Australian Capital Territory (ACT), in August 2021. We calculated attack rates for workplace exposure sites and households, using the number of people present at workplaces and households as the denominator. Thirty confirmed cases were identified, comprised of 13 support workers, six clients, and 11 household and other contacts. The median age of cases was 30.5 years (range 1 to 80 years) and 5 cases (17%) were hospitalised. No cases were admitted to an intensive care unit (ICU) or died. Twenty-two percent of people in close contact with confirmed SARS-CoV-2 cases in this cluster (23/103) subsequently tested positive to SARS-CoV-2. Investigations identified multiple primary cases, with one primary case the likely infection source for at least 17 other cases. Despite the majority being eligible for vaccination, only two cases were fully vaccinated (two doses > 14 days before exposure). The mean secondary attack rate at workplace sites (15% or 12/80 close contacts infected) was lower than the tertiary attack rate (47.8% or 11/23 close contacts infected). The overall risk of contracting SARS-CoV-2 in DSP-related work sites was lower than for household settings (relative risk: 0.42; 95% confidence interval: 0.21-0.82). These findings demonstrate the importance of ongoing collaboration between governments and the disability support sector. Development and delivery of targeted health messaging to people with disability and to disability support workers, regarding infection control in the home setting, and identification of enablers for vaccination, should be the highest priorities from this collaboration.

How do general practitioners test and treat gonococcal infections in the Australian Capital Territory? Implications for disease surveillance and control

The incidence of Neisseria gonorrhoeae (gonorrhoea) and Treponema pallidum (syphilis) infections in the Australian Capital Territory (ACT) has increased since 2014 in people reporting heterosexual exposure. This population is more likely to present to general practice rather than to specialised sexual health clinics, with potential implications for disease surveillance and control. This study aimed to explore: conformity of self-reported clinical practice with sexually transmitted infection guidelines in general practice; gaps in sexual health knowledge and skills; and areas for improved support from ACT Health Communicable Disease Control. A cross-sectional survey of general practitioners (GPs) and nurse practitioners (NPs) practicing in the ACT was conducted in December 2020, using a 17-item questionnaire and semi-structured interviews. Twenty-three GPs and one NP returned completed surveys (response rate 5.3%); four GPs and one NP participated in interviews. In its complex setting of competing demands, GP practice may not always meet national guidelines. In response to clinical vignettes, although all GPs ordered investigations for gonorrhoea, only 25% of these met the gold-standard by including endocervical or vaginal swabs. With respect to assessing antimicrobial sensitivities to guide treatment, only 58% correctly reported following up a positive gonococcal polymerase chain reaction test with a culture. Around two-thirds of respondents (62.5%) identified the appropriate antibiotic therapy and 75% correctly identified the responsibility of the diagnosing clinician to discuss contact tracing with the patient. Suggestions for increased support focussed on education, communication efficiency, and providing a ‘safety net’ for follow up.

Genomic Evidence of In-Flight SARS-CoV-2 Transmission, India to Australia, April 2021

Epidemiologic and genomic investigation of SARS-CoV-2 infections associated with 2 repatriation flights from India to Australia in April 2021 indicated that 4 passengers transmitted SARS-CoV-2 to >11 other passengers. Results suggest transmission despite mandatory mask use and predeparture testing. For subsequent flights, predeparture quarantine and expanded predeparture testing were implemented.

Retrospective analysis of multidrug-resistant tuberculosis case notifications in Australia (1999-2018)

This study describes the epidemiology and treatment outcomes of multidrug-resistant tuberculosis (MDR-TB) cases notified in Australia between 1999 and 2018, and investigates whether current data fields in the national tuberculosis (TB) dataset allow description and measurement of surveillance information pertaining to the diagnosis and clinical management of MDR-TB. In May 2019, de-identified demographic, clinical, laboratory, drug susceptibility, treatment, risk factor and outcome data for all MDR-TB case notifications were extracted from the Australian National Notifiable Disease Surveillance System. The dataset included ten treatment outcome categories, which were aggregated to four categorical outcomes for descriptive and inferential analyses. The majority of cases were overseas-born (91%). Absolute case numbers increased over time; however, the MDR-TB notification rate remained fairly stable during the study period. Treatment success was achieved in nearly two-thirds of cases (62.1%). Whilst timeframes between initial presentation, specimen collection, case notification and treatment commencement were calculated, current data fields in the national dataset precluded measurement and description of other parameters deemed important for MDR-TB surveillance. This study demonstrates that while Australia's MDR-TB burden is low, cases will continue to occur until TB control improves in countries with which Australia shares cultural and migration links. Australia should continue to support national and regional TB control programmes to sustain progress towards national elimination of TB. This study's findings support a review of data fields in the national TB dataset with potential expansion or adjustment to improve national data reporting, including the monitoring of evidence-based recommendations for the prevention and management of MDR-TB.

An outbreak of Bacillus cereus toxin-mediated emetic and diarrhoeal syndromes at a restaurant in Canberra, Australia 2018

A cluster of gastrointestinal illness was detected following receipt of a complaint of becoming ill after a multi-course dinner at a restaurant in Canberra, Australian Capital Territory (ACT), Australia. The complaint led to an investigation by ACT Health. Food samples retained by the restaurant for microbiological analysis returned an unsatisfactory level of Bacillus cereus in beef (19,000 colony forming units/gram [cfu/g]) and a satisfactory level in arancini (50 cfu/g). These positive samples underwent whole genome sequencing and genes encoding diarrhoeal toxins were detected with no laboratory evidence of the emetic toxin. No stool specimens were collected. A cohort study was undertaken and 80% (33/41) of patrons took part in a structured interview. There was no significant difference in age or sex between those ill and not ill. Due to universal exposure most foods were unable to be statistically analysed and no significant results were found from the food history. The ill cohort diverged into two distinct groups based on incubation period and symptoms suggesting this outbreak involved B. cereus intoxication with both diarrhoeal and potentially emetic toxins. Some hygiene practices during food preparation were noted to be inadequate and heating and cooling procedures were unverified when questioned. A combination of the incubation periods and symptom profile, food laboratory evidence, and genomic sequencing of the B. cereus diarrhoeal gene suggest a probable aetiology of B. cereus intoxication. Public health action included the restaurant rectifying hygiene practices and documenting heating/cooling procedures.

Identification of Biological Hazards in Produce Consumed in Industrialized Countries: A Review

Microbial contamination of fresh produce (fresh fruits and vegetables) poses serious public health concerns worldwide. This study was conducted as a comprehensive analysis of biological hazards in the global fresh produce chain. Data about produce-related outbreaks and illness were collected from the annual reports and databases of foodborne outbreak surveillance systems in different regions and countries from 2010 to 2015. The global patterns of and regional differences in documented outbreaks and cases were analyzed, and produce commodities and pathogens of greatest concern were identified. Data on sporadic illnesses were also collected through a comprehensive literature review of case-control studies. We found 988 produce-related outbreaks (with known agents) and 45,723 cases in all regions and countries. The numbers of produce-related outbreaks per million person-years were approximately 0.76, 0.26, 0.25, 0.13, 0.12, and 0.05 in New Zealand, Australia, the United States, the European Union, Canada, and Japan, respectively. The top three food categories and pathogens contributing to produce-related outbreaks were vegetables and nonfruits (i.e., food other than fruits; 27.0%), unspecified vegetables (12.2%), and vegetable row crops (11.7%) and norovirus (42.4%), Salmonella enterica (19.9%), and Staphylococcus aureus (7.9%), respectively. Produce consumption was identified as a protective factor, a risk factor, and either a protective or risk factor for sporadic illnesses in 11, 5, and 5 studies, respectively, among 21 case-control studies. Risks associated with produce consumption in the United States and the European Union have been linked to various factors such as irrigation water, cross-contamination, storage time and temperature abuse, infected food handlers, and unprocessed contaminated ingredients. The results of the current study indicate the complexity of produce products consumed across the globe and the difficulty in tracing illnesses back to specific food ingredients.

OzFoodNet quarterly report, 1 April to 30 June 2015

The Australian Government Department of Health established the OzFoodNet network in 2000 to collaborate nationally to investigate foodborne disease. In each Australian state and territory, OzFoodNet epidemiologists investigate outbreaks of enteric infection. In addition, OzFoodNet conducts studies on the burden of illness and coordinates national investigations into outbreaks of foodborne disease. This quarterly report documents investigations of outbreaks of gastrointestinal illness and clusters of disease potentially related to food, which commenced in Australia between 1 April and 30 June 2015. Data were received from OzFoodNet epidemiologists in all Australian states and territories. The data in this report are provisional and subject to change. During the 2nd quarter of 2015 (1 April to 30 June), OzFoodNet sites reported 352 outbreaks of enteric illness, including those transmitted by contaminated food or water. Outbreaks of gastroenteritis are often not reported to health authorities, which results in current figures under-representing the true burden of enteric disease outbreaks within Australia. There were 5,214 people affected in these outbreaks and 192 hospitalisations. There were 11 deaths reported during these outbreaks. This represents a decrease in the number of people affected compared with the 5-year average from 2010 to 2014 for the 2nd quarter (8,191). The majority of reported outbreaks of gastrointestinal illness in Australia are due to person-to-person transmission. In this quarter, 72% (255/352) of outbreaks were transmitted via this route (see Table 1). This percentage was similar to the same quarter in 2014 (73%, 305/419) but the total number is lower than the 5-year average (2nd quarter, 2010-2014) of 360 outbreaks transmitted person-to-person. Of the person-to-person outbreaks in the 2nd quarter of 2015, 47% (119/255) occurred in child care facilities and 40% (102/255) occurred in aged care facilities.

OzFoodNet quarterly report, 1 July to 30 September 2015

The Australian Government Department of Health established the OzFoodNet network in 2000 to collaborate nationally to investigate foodborne disease. In each Australian state and territory, OzFoodNet epidemiologists investigate outbreaks of enteric infection. In addition, OzFoodNet conducts studies on the burden of illness and coordinates national investigations into outbreaks of foodborne disease. This quarterly report documents investigations of outbreaks of gastrointestinal illness and clusters of disease potentially related to food, which commenced in Australia between 1 July and 30 September 2015.

Hepatitis E virus infections in travellers: assessing the threat to the Australian blood supply

BACKGROUND

In many developed countries hepatitis E virus (HEV) infections have occurred predominantly in travellers to countries endemic for HEV. HEV is a potential threat to blood safety as the virus is transfusion-transmissible. To minimise this risk in Australia, individuals diagnosed with HEV are deferred. Malarialdeferrals, when donors are restricted from donating fresh blood components following travel toanareain which malaria is endemic, probably also decrease the HEV risk, by deferring donors who travel to many countries also endemic for HEV. The aim of this study is to describe overseas-acquired HEV cases in Australia, in order to determine whether infection in travellers poses a risk to Australian blood safety.

MATERIALS AND METHODS

Details of all notified HEV cases in Australia from 2002 to 2014 were accessed, and importation rates estimated. Countries in which HEV was acquired were compared to those for which donations are restricted following travel because of a malaria risk.

RESULTS

Three hundred and thirty-two cases of HEV were acquired overseas. Travel to India accounted for most of these infections, although the importation rate was highest for Nepal and Bangladesh. Countries for which donations are restricted following travel due to malaria risk accounted for 94% of overseas-acquired HEV cases.

DISCUSSION

The vast majority of overseas-acquired HEV infections were in travellers returning from South Asian countries, which are subject to donation-related travel restrictions for malaria. This minimises the risk HEV poses to the Australian blood supply.

OzFoodNet into the future: the rapid evolution of foodborne disease surveillance in Australia

OzFoodNet is Australia's national enhanced foodborne disease surveillance network. OzFoodNet is currently evolving in order to meet the most significant challenges faced since it commenced in 2000: the transition to culture independent diagnostic tests and the introduction of whole genome sequencing for typing of enteric pathogens. This has changed the nature of foodborne disease surveillance and outbreak investigation in Australia.

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.

Outbreak-related Hendra virus infection in a NSW pet dog

Hendra virus (HeV) infection is a zoonosis of importance in Australia. An outbreak of HeV occurred on the mid-north coast region of New South Wales (NSW) in June and July 2013. Four unvaccinated horses on four separate properties were confirmed to have HeV infection. A pet dog that had close contact with one of the horses was also confirmed to be infected with HeV. This paper documents the response to the canine infection and the resulting change to the public health management of HeV infection.