Changes in isolation guidelines for CPE patients results in only mild reduction in required hospital beds.

Background: Carbapenemase-producing Enterobacterales (CPE) are an emerging public health concern globally as they are resistant to a broad spectrum of antibiotics. Colonisation with CPE typically requires patients to be managed under 'contact precautions', which creates additional physical bed demands in healthcare facilities.

Methods: This study examined the potential impact of revised isolation guidelines introduced in late 2023 in Victoria, Australia, that relaxed the requirement for indefinite isolation of CPE-colonised patients in contact precautions, based on admission of CPE-diagnosed cases prior to the guideline change.

Carbapenemase-producing enterobacterales colonisation status does not lead to more frequent admissions: a linked patient study.

Background: Hospitals in any given region can be considered as part of a network, where facilities are connected to one another - and hospital pathogens potentially spread - through the movement of patients between them. We sought to describe the hospital admission patterns of patients known to be colonised with carbapenemase-producing Enterobacterales (CPE), and compare them with CPE-negative patient cohorts, matched on comorbidity information.

Methods: We performed a linkage study in Victoria, Australia, including datasets with notifiable diseases (CPE notifications) and hospital admissions (admission dates and diagnostic codes) for the period 2011 to 2020.

Opportunities to strengthen respiratory virus surveillance systems in Australia: lessons learned from the COVID-19 response.

Disease surveillance data was critical in supporting public health decisions throughout the coronavirus disease 2019 (COVID-19) pandemic. At the same time, the unprecedented circumstances of the pandemic revealed many shortcomings of surveillance systems for viral respiratory pathogens. Strengthening of surveillance systems was identified as a priority for the recently established Australian Centre for Disease Control, which represents a critical opportunity to review pre-pandemic and pandemic surveillance practices, and to decide on future priorities, during both pandemic and inter-pandemic periods.

Modelling the impact of hybrid immunity on future COVID-19 epidemic waves.

Background: Since the emergence of SARS-CoV-2 (COVID-19), there have been multiple waves of infection and multiple rounds of vaccination rollouts. Both prior infection and vaccination can prevent future infection and reduce severity of outcomes, combining to form hybrid immunity against COVID-19 at the individual and population level. Here, we explore how different combinations of hybrid immunity affect the size and severity of near-future Omicron waves.

Estimating the impact of test-trace-isolate-quarantine systems on SARS-CoV-2 transmission in Australia.

Background: Australian states and territories used test-trace-isolate-quarantine (TTIQ) systems extensively in their response to the COVID-19 pandemic in 2020-2021. We report on an analysis of Australian case data to estimate the impact of test-trace-isolate-quarantine systems on SARS-CoV-2 transmission.

Methods: Our analysis uses a novel mathematical modelling framework and detailed surveillance data on COVID-19 cases including dates of infection and dates of isolation.

The incidence of nosocomial bloodstream infection and urinary tract infection in Australian hospitals before and during the COVID-19 pandemic: an interrupted time series study.

Background: The COVID-19 pandemic has had a significant impact on healthcare including increased awareness of infection prevention and control (IPC). The aim of this study was to explore if the heightened awareness of IPC measures implemented in response to the pandemic influenced the rates of healthcare associated infections (HAI) using positive bloodstream and urine cultures as a proxy measure.

Methods: A 3 year retrospective review of laboratory data from 5 hospitals (4 acute public, 1 private) from two states in Australia was undertaken.

COVID-19 in low-tolerance border quarantine systems: Impact of the Delta variant of SARS-CoV-2.

In controlling transmission of coronavirus disease 2019 (COVID-19), the effectiveness of border quarantine strategies is a key concern for jurisdictions in which the local prevalence of disease and immunity is low. In settings like this such as China, Australia, and New Zealand, rare outbreak events can lead to escalating epidemics and trigger the imposition of large-scale lockdown policies. Here, we develop and apply an individual-based model of COVID-19 to simulate case importation from managed quarantine under various vaccination scenarios.

Understanding how Victoria, Australia gained control of its second COVID-19 wave.

During 2020, Victoria was the Australian state hardest hit by COVID-19, but was successful in controlling its second wave through aggressive policy interventions. We calibrated a detailed compartmental model of Victoria's second wave to multiple geographically-structured epidemic time-series indicators. We achieved a good fit overall and for individual health services through a combination of time-varying processes, including case detection, population mobility, school closures, physical distancing and face covering usage.

Risk mapping for COVID-19 outbreaks in Australia using mobility data.

COVID-19 is highly transmissible and containing outbreaks requires a rapid and effective response. Because infection may be spread by people who are pre-symptomatic or asymptomatic, substantial undetected transmission is likely to occur before clinical cases are diagnosed. Thus, when outbreaks occur there is a need to anticipate which populations and locations are at heightened risk of exposure.

Bringing evidence from press release to the clinic in the era of COVID-19.

The urgent need to develop effective therapeutics and disseminate information from clinical studies has led to data from clinical trials being made available by alternate methods prior to peer-reviewed publication, including press releases, social media and pre-print papers. While this allows clinicians more open access to these data, a trust has to be placed with the investigators releasing these data without the availability of scientifically rigorous peer review. The examples of results from trials studying dexamethasone and hydroxychloroquine for treatment of COVID-19 have had contrasting outcomes, including the potential for significant numbers of lives saved with the early release of results from the RECOVERY trial studying dexamethasone contrasting with unsubstantiated data being presented from trials studying hydroxychloroquine.

Estimation of the force of infection and infectious period of skin sores in remote Australian communities using interval-censored data.

Prevalence of impetigo (skin sores) remains high in remote Australian Aboriginal communities, Fiji, and other areas of socio-economic disadvantage. Skin sore infections, driven primarily in these settings by Group A Streptococcus (GAS) contribute substantially to the disease burden in these areas. Despite this, estimates for the force of infection, infectious period and basic reproductive ratio-all necessary for the construction of dynamic transmission models-have not been obtained.

High burden of infectious disease and antibiotic use in early life in Australian Aboriginal communities.

Objective: To quantify the childhood infectious disease burden and antibiotic use in the Northern Territory's East Arnhem region through synthesis and analysis of historical data resources.

Methods: We combined primary health clinic data originally reported in three separate publications stemming from the East Arnhem Healthy Skin Project (Jan-01 to Sep-07). Common statistical techniques were used to explore the prevalence of infectious conditions and the seasonality of infections, and to measure rates of antibiotic use.

Indigenous Australian household structure: a simple data collection tool and implications for close contact transmission of communicable diseases.

Households are an important location for the transmission of communicable diseases. Social contact between household members is typically more frequent, of greater intensity, and is more likely to involve people of different age groups than contact occurring in the general community. Understanding household structure in different populations is therefore fundamental to explaining patterns of disease transmission in these populations.

Choice of Antiviral Allocation Scheme for Pandemic Influenza Depends on Strain Transmissibility, Delivery Delay and Stockpile Size.

Recently, pandemic response has involved the use of antivirals. These antivirals are often allocated to households dynamically throughout the pandemic with the aim being to retard the spread of infection. A drawback of this is that there is a delay until infection is confirmed and antivirals are delivered.