Acute hepatitis of unknown aetiology in children: evidence for and against causal relationships with SARS-CoV-2, HAdv and AAV2.

Background: The cause of acute paediatric hepatitis of unknown aetiology (2022) has not been established despite extensive investigation.

Objective: To summarise the evidence for and against a causal role for human adenovirus (HAdv), adeno-associated virus 2 (AAV-2) and SARS-CoV-2 in outbreaks of paediatric hepatitis in 2022.

Methods: We appraised and summarised relevant evidence for each of the Bradford Hill criteria for causality using quantitative (statistical modelling) and qualitative (narrative coherence) approaches.

Influenza cases in nine aged care facilities in Sydney, Australia over a three-year surveillance period, 2018-2020.

Background: Influenza outbreaks in aged care facilities are a major public health concern. In response to the severe 2017 influenza season in Australia, enhanced influenza vaccines were introduced from 2018 onwards for those over 65 and more emphasis was placed on improving vaccination rates among aged care staff. During the COVID-19 pandemic, these efforts were then further escalated to reduce the additional burden that influenza could pose to facilities.

Evidence for Residual Immunity to Smallpox After Vaccination and Implications for Re-emergence.

Introduction: Smallpox has been eradicated but advances in synthetic biology have increased the risk of its re-emergence. Residual immunity in individuals who were previously vaccinated may mitigate the impact of an outbreak, but there is a high degree of uncertainty about the duration and degree of residual immunity. Both cell-mediated and humoral immunity are thought to be important but the exact mechanisms of protection are unclear.

Health system capacity in Sydney, Australia in the event of a biological attack with smallpox.

Planning for a re-emergent epidemic of smallpox requires surge capacity of space, resources and personnel within health systems. There are many uncertainties in such a scenario, including likelihood and size of an attack, speed of response and health system capacity. We used a model for smallpox transmission to determine requirements for hospital beds, contact tracing and health workers (HCWs) in Sydney, Australia, during a modelled epidemic of smallpox.

Epidemic intelligence needs of stakeholders in the Asia-Pacific region.

Objective: To understand the global outbreak surveillance needs of stakeholders involved in epidemic response in selected countries and areas in the Asia-Pacific region to inform development of an epidemic observatory, Epi-watch.

Methods: We designed an online, semi-structured stakeholder questionnaire to collect information on global outbreak surveillance sources and limitations from participants who use epidemic intelligence and outbreak alert services in their work in government and nongovernment organizations in the Asia-Pacific region.

Results: All respondents agreed that it was important to remain up to date with global outbreaks.