El Niño Southern Oscillation, overseas arrivals and imported chikungunya cases in Australia: A time series analysis
PLOS Neglected Tropical Diseases·
- DOI
- 10.1371/journal.pntd.0007376
- PMID
- 31107863
- PMCID
- PMC6544329
- OpenAlex
- —
- Study type
- Journal article
- Publisher
- Public Library of Science (PLoS)
- Article type
- journal-article
- Integrity
- current
Why this research matters now
Findings are relevant for anticipating periods of higher importation risk and considering climatic drivers of overseas chikungunya activity when planning Australian preparedness, given the presence of suitable local vectors.
Structured evidence summary
Research question
The study investigates whether overseas arrivals and the El Niño Southern Oscillation are associated with monthly imported chikungunya cases in Australia.
Study design
Time series analysis using seasonal decomposition of monthly imported case and arrival counts, with wavelet coherence analysis examining transient relationships between cases and the Southern Oscillation Index.
Population and setting
Monthly imported chikungunya cases reported in Australia and monthly overseas arrivals to Australia, examined over a multi-year period.
Main findings
The number and geographical range of source countries for imported cases increased over time, and monthly imported cases showed an unstable increasing trend compared with a more stable increase in overseas arrivals. Both series displayed substantial seasonality, with strongest peaks in January followed by October and July. Wavelet coherence analysis identified four periods (2009–2010, 2012, 2014, and 2015–2016) of significant transient coherence between monthly imported cases and a 6-month lagged moving average of the Southern Oscillation Index.
Public-health relevance
Findings are relevant for anticipating periods of higher importation risk and considering climatic drivers of overseas chikungunya activity when planning Australian preparedness, given the presence of suitable local vectors.
Important limitations
The summary is limited to the supplied single-article abstract and metadata; decision-grade interpretation requires the original paper. The abstract notes that imported case counts showed an unstable trend, suggesting sensitivity to reporting or case ascertainment, but does not enumerate explicit study limitations.
GIDS interpretation
The paper provides contextual evidence on seasonal and climatic correlates of chikungunya importation to Australia and may support discovery of travel- and climate-linked import patterns; it does not by itself constitute confirmation of any active surveillance signal.
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.