Intense interseasonal influenza outbreaks, Australia, 2018/19
Eurosurveillance·
- DOI
- 10.2807/1560-7917.es.2019.24.33.1900421
- PMID
- —
- PMCID
- —
- OpenAlex
- W2968124252
- Study type
- Journal article
- Publisher
- European Centre for Disease Control and Prevention (ECDC)
- Article type
- journal-article
- Integrity
- current
Why this research matters now
These unprecedented interseasonal outbreaks followed a mild 2018 influenza season and highlight the need for year-round influenza surveillance even in temperate climates with strong seasonal patterns. The event underscores that interseasonal influenza activity can reach levels comparable to or exceeding typical seasonal peaks.
Structured evidence summary
Research question
The study examined the epidemiological extent of the unusually large 2018/19 interseasonal influenza outbreaks in Australia and investigated the genetic, antigenic, and structural properties of the responsible viruses.
Study design
This was an observational study combining epidemiological and virological surveillance data from multiple Australian health agencies, sentinel outpatient surveillance, public health laboratories, and WHO and Singaporean research centers.
Population and setting
The study covered influenza cases across Australia during the interseasonal period from November 2018 to May 2019, including institutional outbreaks, hospitalized patients, and deaths.
Main findings
A record 85,286 laboratory-confirmed influenza cases occurred during the November 2018 to May 2019 interseasonal period, representing five times the previous three-year average. The outbreaks also produced more institutional outbreaks, hospitalizations, and deaths than typically observed during interseasonal periods, and led to a very early start to the 2019 influenza season.
Public-health relevance
These unprecedented interseasonal outbreaks followed a mild 2018 influenza season and highlight the need for year-round influenza surveillance even in temperate climates with strong seasonal patterns. The event underscores that interseasonal influenza activity can reach levels comparable to or exceeding typical seasonal peaks.
Important limitations
The authors note that the reasons for this unusual event have not been fully elucidated. This summary relies on the supplied single-article abstract and metadata; access to the full paper would enable more complete interpretation of methods, data quality, and analytical limitations.
GIDS interpretation
This paper was classified under influenza surveillance and outbreak investigation topics for Australia. It documents an atypical interseasonal event that may inform detection thresholds and alert criteria for similar anomalies in temperate-climate surveillance systems.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 8 auditable classifier relationships to diseases, places, topics, and study design.