Household transmission investigation: Design, reporting and critical appraisal.

Background: Household transmission investigations (HHTIs) contribute timely epidemiologic knowledge in response to emerging pathogens. HHTIs conducted in the context of the COVID-19 pandemic in 2020-21 reported variable methodological approaches, producing epidemiological estimates that vary in meaning, precision and accuracy. Because specific tools to assist with the optimal design and critical appraisal of HHTIs are not available, the aggregation and pooling of inferences from HHTIs to inform policy and interventions may be challenging.

Evaluation of the Australian first few X household transmission project for COVID-19.

Background: The Australian First Few X (FFX) Household Transmission Project for COVID-19 was the first prospective, multi-jurisdictional study of its kind in Australia. The project was undertaken as a partnership between federal and state health departments and the Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE) and was active from April to October 2020.

Methods: We aimed to identify and explore the challenges and strengths of the Australian FFX Project to inform future FFX study development and integration into pandemic preparedness plans.

Influenza epidemiology and burden of disease in Mongolia, 2013-2014 to 2017-2018.

Background: Mongolia is a vast, sparsely populated country in central Asia. Its harsh climate and nomadic lifestyle make the population vulnerable to acute respiratory infections, particularly influenza. Evidence on the morbidity, mortality and socioeconomic impact of influenza in Mongolia is scarce; however, routine surveillance for influenza-like illness (ILI), severe acute respiratory infection (SARI) and laboratory-detected influenza is conducted.

Intraseason decline in influenza vaccine effectiveness during the 2016 southern hemisphere influenza season: A test-negative design study and phylogenetic assessment.

Background: We estimated the effectiveness of seasonal inactivated influenza vaccine and the potential influence of timing of immunization on vaccine effectiveness (VE) using data from the 2016 southern hemisphere influenza season.

Methods: Data were pooled from three routine syndromic sentinel surveillance systems in general practices in Australia. Each system routinely collected specimens for influenza testing from patients presenting with influenza-like illness.

Epidemic forecasts as a tool for public health: interpretation and (re)calibration.

Objective: Recent studies have used Bayesian methods to predict timing of influenza epidemics many weeks in advance, but there is no documented evaluation of how such forecasts might support the day-to-day operations of public health staff.

Methods: During the 2015 influenza season in Melbourne, Australia, weekly forecasts were presented at Health Department surveillance unit meetings, where they were evaluated and updated in light of expert opinion to improve their accuracy and usefulness.

Results: Predictive capacity of the model was substantially limited by delays in reporting and processing arising from an unprecedented number of notifications, disproportionate to seasonal intensity.

Low interim influenza vaccine effectiveness, Australia, 1 May to 24 September 2017.

In 2017, influenza seasonal activity was high in the southern hemisphere. We present interim influenza vaccine effectiveness (VE) estimates from Australia. Adjusted VE was low overall at 33% (95% confidence interval (CI): 17 to 46), 50% (95% CI: 8 to 74) for A(H1)pdm09, 10% (95% CI: -16 to 31) for A(H3) and 57% (95% CI: 41 to 69) for influenza B.

Influenza testing trends in sentinel surveillance general practices in Victoria 2007 to 2014.

The Victorian Sentinel Practice Influenza Network conducts syndromic surveillance for influenza-like illness (ILI), with testing for laboratory confirmation of a proportion of cases at the discretion of general practitioners. The aim of this study was to evaluate the consistency of sentinel general practitioners' swabbing practice within and between influenza seasons. Aggregated, weekly, non-identified data for May to October each year from 2007 to 2014 were used to calculate the proportion of patients presenting with ILI (defined as cough, fever and fatigue), proportion of ILI patients swabbed and proportion of swabs positive for influenza.

Effectiveness of seasonal influenza vaccine in Australia, 2015: An epidemiological, antigenic and phylogenetic assessment.

Background: A record number of laboratory-confirmed influenza cases were notified in Australia in 2015, during which type A(H3) and type B Victoria and Yamagata lineages co-circulated. We estimated effectiveness of the 2015 inactivated seasonal influenza vaccine against specific virus lineages and clades.

Methods: Three sentinel general practitioner networks conduct surveillance for laboratory-confirmed influenza amongst patients presenting with influenza-like illness in Australia.

Transmission of the First Influenza A(H1N1)pdm09 Pandemic Wave in Australia Was Driven by Undetected Infections: Pandemic Response Implications.

Background: During the first wave of influenza A(H1N1)pdm09 in Victoria, Australia the rapid increase in notified cases and the high proportion with relatively mild symptoms suggested that community transmission was established before cases were identified. This lead to the hypothesis that those with low-level infections were the main drivers of the pandemic.

Methods: A deterministic susceptible-infected-recovered model was constructed to describe the first pandemic wave in a population structured by disease severity levels of asymptomatic, low-level symptoms, moderate symptoms and severe symptoms requiring hospitalisation.

Understanding influenza vaccine protection in the community: an assessment of the 2013 influenza season in Victoria, Australia.

Background: The influenza virus undergoes frequent antigenic drift, necessitating annual review of the composition of the influenza vaccine. Vaccination is an important strategy for reducing the impact and burden of influenza, and estimating vaccine effectiveness (VE) each year informs surveillance and preventative measures. We aimed to describe the influenza season and to estimate the effectiveness of the influenza vaccine in Victoria, Australia, in 2013.

Systematic review of influenza A(H1N1)pdm09 virus shedding: duration is affected by severity, but not age.

Duration of viral shedding following infection is an important determinant of disease transmission, informing both control policies and disease modelling. We undertook a systematic literature review of the duration of influenza A(H1N1)pdm09 virus shedding to examine the effects of age, severity of illness and receipt of antiviral treatment. Studies were identified by searching the PubMed database using the keywords 'H1N1', 'pandemic', 'pandemics', 'shed' and 'shedding'.

A cross sectional survey of attitudes, awareness and uptake of the parental pertussis booster vaccine as part of a cocooning strategy, Victoria, Australia.

Background: The Victorian Government Department of Health funded a diphtheria, tetanus and acellular pertussis vaccine for parents of infants from June 2009 to June 2012 as part of a cocooning strategy for the control of pertussis. The aim of this study was to assess parents' attitudes and awareness of the vaccination program, and to estimate vaccine uptake.

Methods: A cross-sectional survey of 253 families with a child born in the first quarter of 2010 residing within five metropolitan and four rural local government areas in Victoria was conducted.

The spread of influenza A(H1N1)pdm09 in Victorian school children in 2009: implications for revised pandemic planning.

Background: Victoria was the first state in Australia to experience community transmission of influenza A(H1N1)pdm09. We undertook a descriptive epidemiological analysis of the first 1,000 notified cases to describe the epidemic associated with school children and explore implications for school closure and antiviral distribution policy in revised pandemic plans.

Methods: Records of the first 1,000 laboratory-confirmed cases of influenza A(H1N1)pdm09 notified to the Victorian Government Department of Health between 20 May and 5 June 2009 were extracted from the state's notifiable infectious diseases database.

Leave entitlements, time off work and the household financial impacts of quarantine compliance during an H1N1 outbreak.

Background: The Australian state of Victoria, with 5.2 million residents, enforced home quarantine during a H1N1 pandemic in 2009. The strategy was targeted at school children.

Moderate influenza vaccine effectiveness with variable effectiveness by match between circulating and vaccine strains in Australian adults aged 20-64 years, 2007-2011.

Background: Influenza vaccines are licensed annually based on immunogenicity studies. We used five sequential years of data to estimate influenza vaccine effectiveness (VE), the critical outcome in the field.

Methods: Between 2007 and 2011, we performed annual prospective test-negative design case-control studies among adults aged 20-64 years recruited from sentinel general practices in the Australian state of Victoria.