Differential COVID-19 case ascertainment by age and vaccination status in Victoria, Australia: a serosurveillance and record linkage study.

Objectives: To compare serological evidence of prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with linked coronavirus disease 2019 (COVID-19) case notification data in Victoria, Australia, and to determine SARS-CoV-2 neutralisation activity based on prior infection and vaccination history.

Design, Setting, Participants: Four cross-sectional serological surveys were conducted between 30 June and 31 October 2022 (a period of Omicron BA.4/BA.

Hepatitis B clinical care provision in pregnancy: A whole-of-population linkage study in Victoria, Australia.

Background And Aim: Pregnancy is a key setting for engagement in chronic hepatitis B (CHB) care, due to the implications for transmission to the infant and antenatal diagnosis representing an opportunity for ongoing follow-up. This study aimed to identify the coverage and predictors of clinical care for women with CHB during and after pregnancy in a population-level cohort.

Methods: Notified CHB cases in Victoria, Australia, were linked with hospitalizations, medical services, and prescribing data, covering the period 1991-2018.

The cascade of care for hepatitis C in Victoria, Australia: a data linkage cohort study.

Background: Highly effective hepatitis C therapies are available in Australia. However, people living with hepatitis C face various barriers to accessing care and treatment.

Aims: To identify gaps in the cascade of care for hepatitis C and generate estimates of the number living with untreated infection according to population group, using a representative longitudinal study population.

The relative effectiveness of three and four doses of COVID-19 vaccine in Victoria, Australia: A data linkage study.

Background: The Coronavirus Disease 2019 (COVID-19) pandemic led to extensive vaccination campaigns worldwide, including in Australia. Immunity waning and the emergence of new viral variants pose challenges to the effectiveness of vaccines. Our study aimed to assess the relative effectiveness (rVE) of 3 and 4 compared with 2 doses of COVID-19 vaccine.

Excess mortality among people with communicable diseases over a 30-year period, Victoria, Australia: a whole of population cohort study.

Background: Understanding mortality burden associated with communicable diseases is key to informing resource allocation, disease prevention and control efforts, and evaluating public health interventions. We quantified excess mortality among people notified with communicable diseases in Victoria, Australia.

Methods: Cases of communicable disease notified in Victoria between 1 January 1991 and 31 December 2021 were linked to the death registry.

Missed opportunities for diagnosis of hepatitis B and C in individuals diagnosed with decompensated cirrhosis or hepatocellular carcinoma.

Background And Aim: This study aimed to assess utilization of health-care services in people with decompensated cirrhosis (DC) or hepatocellular carcinoma (HCC) and a "late diagnosis" of hepatitis B or hepatitis C.

Methods: Hepatitis B and C cases during 1997-2016 in Victoria, Australia, were linked with hospitalizations, deaths, liver cancer diagnoses, and medical services. A late diagnosis was defined as hepatitis B or hepatitis C notification occurring after, at the same time, or within 2 years preceding an HCC/DC diagnosis.

Uptake of perinatal immunoprophylaxis for infants born to women with a record of hepatitis B in Victoria (2009-2017).

Background: Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) remains one of the leading causes of transmission worldwide. An estimated 90 % of infants who are exposed to HBV and do not receive appropriate post exposure immunoprophylaxis will go on to develop chronic hepatitis B (CHB). In Australia, universal birth dose vaccination was adopted in 2000 and universal antenatal screening for hepatitis B was introduced in the 1990 s, however up to 10 % of women may have missed screening.

Mapping the delivery of interventions for vaccine-preventable infections in pregnancy in Victoria, Australia.

Background: Standard care for pregnant women includes universal screening for hepatitis B, and administration of influenza and pertussis vaccination to women and hepatitis B infant vaccination. This study explored how perinatal services relating to the prevention of these vaccine-preventable diseases are delivered to women and their infants in Victoria, Australia.

Methods: Two online surveys investigated service delivery for the prevention of influenza, pertussis and hepatitis B to identify barriers to optimal care during January-June 2021; (1) The Birthing Hospitals Survey captured facility-level information about service delivery for influenza and pertussis vaccination, and interventions to prevent mother-to-child-transmission of chronic hepatitis B (CHB); and (2) The Healthcare Providers Survey captured individual staff perceptions and knowledge in community and hospital settings.

Associations between COVID-19 and hospitalisation with respiratory and non-respiratory conditions: a record linkage study.

Objectives: To assess associations between SARS-CoV-2 infection and the incidence of hospitalisation with selected respiratory and non-respiratory conditions in a largely SARS-CoV-2 vaccine-naïve population .

Design, Setting, Participants: Self-control case series; analysis of population-wide surveillance and administrative data for all laboratory-confirmed COVID-19 cases notified to the Victorian Department of Health (onset, 23 January 2020 - 31 May 2021; ie, prior to widespread vaccination rollout) and linked hospital admissions data (admission dates to 30 September 2021).

Main Outcome Measures: Hospitalisation of people with acute COVID-19; incidence rate ratios (IRRs) comparing incidence of hospitalisations with defined conditions (including cardiac, cerebrovascular, venous thrombo-embolic, coagulative, and renal disorders) from three days before to within 89 days of onset of COVID-19 with incidence during baseline period (60-365 days prior to COVID-19 onset).

Maternal Vaccination and Infant Influenza and Pertussis.

Background And Objectives: Infant influenza and pertussis disease causes considerable morbidity and mortality worldwide. We examined the effectiveness of maternal influenza and pertussis vaccines in preventing these diseases in infants.

Methods: This inception cohort study comprised women whose pregnancies ended between September 1, 2015, and December 31, 2017, in Victoria, Australia.

Changes in infection-related hospitalizations in children following pandemic restrictions: an interrupted time-series analysis of total population data.

Background: Infectious diseases are a leading cause of hospitalization during childhood. The various mitigation strategies implemented to control the coronavirus disease (COVID-19) pandemic could have additional, unintended benefits for limiting the spread of other infectious diseases and their associated burden on the health care system.

Methods: We conducted an interrupted time-series analysis using population-wide hospitalization data for the state of Victoria, Australia.

An evaluation of enhanced surveillance of hospitalised COVID-19 patients to inform the public health response in Victoria.

Background: Public health surveillance is crucial for supporting a rapid and effective response to public health emergencies. In response to the coronavirus disease (COVID-19) pandemic, an enhanced surveillance system of hospitalised COVID-19 patients was established by the Victorian Department of Health and Human Services (DHHS) and the Victorian Healthcare Associated Infection Surveillance System Coordinating Centre. The system aimed to reduce workforce capacity constraints and increase situational awareness on the status of hospitalised patients.

Influenza and pertussis vaccination of women during pregnancy in Victoria, 2015-2017.

Objectives: To assess variations by time of year and hospital in the uptake of influenza and pertussis vaccinations by pregnant women in Victoria; to identify factors associated with vaccination uptake.

Design, Setting: Retrospective analysis of data in the Victorian Perinatal Data Collection (VPDC), a population surveillance system for obstetric conditions, procedures, and pregnancy and birth outcomes.

Participants: Women whose pregnancies ended in a live or stillbirth during July 2015 - June 2017.

Use of data linkage to improve communicable disease surveillance and control in Australia: existing practices, barriers and enablers.

Objectives: To review the use of data linkage by Australian state and territory communicable disease control units, and to identify barriers to and enablers of data linkage to inform communicable disease surveillance and control activities.

Methods: Semi-structured telephone interviews were carried out with one key informant from communicable disease control units in all eight Australian states and territories between October 2017 and January 2018.

Results: Key informants from all Australian states and territories participated in the interview.

The Rise of Imported Dengue Infections in Victoria, Australia, 2010⁻2016.

Dengue notifications have increased dramatically over the past seven years in Victoria, Australia-a trend which has been seen nationally and reflects increased cases internationally. We reviewed the epidemiology of dengue among Victorian travellers, changes in diagnostic methods and describe the burden placed on local health systems resulting from this disease of public health importance. Cases of dengue notified to the Department of Health and Human Services in Victoria, Australia, between 1 January 2010 and 31 December 2016 were included in this review.

Effectiveness of parental cocooning as a vaccination strategy to prevent pertussis infection in infants: A case-control study.

Background: During a pertussis epidemic in 2009, the Department of Health, Victoria, Australia, implemented a cocoon program offering parents of new babies a funded-dose of pertussis-containing vaccine. We assessed vaccine effectiveness (VE) of the program in reducing pertussis infection in infants.

Methods: Using a matched case-control design, infants aged <12 months that were notified with pertussis between 1 January 2010 and 31 December 2011, and born during the time that the cocoon program was in place, were identified.

Using data linkage to improve the completeness of Aboriginal and Torres Strait Islander status in communicable disease notifications in Victoria.

Objective: The burden of notifiable diseases in Aboriginal and Torres Strait Islander Victorians cannot be accurately estimated due to under-reporting of Indigenous status. We used data linkage to improve completeness of Indigenous status in people notified with viral hepatitis and gonococcal infection.

Methods: Notifications made between 2009 and 2010 were linked with Victorian hospitalisation data (1997-2011).

Uptake of a government-funded pertussis-containing booster vaccination program for parents of new babies in Victoria, Australia.

Introduction: An epidemic of Bordetella pertussis in Victoria, Australia, led to the implementation of a Government-funded vaccination program for parents of new babies. The rationale was to protect unimmunised infants from infection by vaccinating parents with a pertussis-containing vaccine. This is known as cocooning.

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.

Small area analysis of ambulatory care sensitive conditions in Victoria, Australia.

Ambulatory care sensitive conditions (ACSCs) are used as a measure of access to primary health care. The purpose of this study was to identify factors associated with variation in ACSC admissions at a small area level in Victoria, Australia. The study was ecologic, using Victorian Primary Care Partnerships (PCPs) as the unit of analysis.

A multistate outbreak of hepatitis A associated with semidried tomatoes in Australia, 2009.

Background: A large outbreak of hepatitis A affected individuals in several Australian states in 2009, resulting in a 2-fold increase in cases reported to state health departments compared with 2008. Two peaks of infection occurred (April-May and September-November), with surveillance data suggesting locally acquired infections from a widely distributed food product.

Methods: Two case-control studies were completed.

Syndromic surveillance for influenza in two hospital emergency departments. Relationships between ICD-10 codes and notified cases, before and during a pandemic.

Background: Interest in the use of emergency department (ED) data by syndromic surveillance systems to detect influenza outbreaks has been growing. Evaluations of these systems generally focus on events during influenza seasons. The aims of this study were to identify which emergency department disease codes best correlated with confirmed influenza cases and to determine if these same codes would be useful in the non-influenza season.