Analyzing climate variations at multiple timescales can guide Zika virus response measures

Area of Science:

• Environmental Science
• Epidemiology
• Climate Science

Background:

• The 2014-2016 Zika virus (ZIKV) emergence coincided with severe drought and high temperatures, linked to El Niño and climate change.
• Previous studies suggest ZIKV transmission is sensitive to climate seasonality and variability, but quantitative assessments are lacking.

Purpose of the Study:

• To quantitatively assess the climate conditions conducive to the 2014-2016 Zika virus epidemic in Latin America.
• To inform the development of climate-informed prevention and control strategies for ZIKV.

Main Methods:

• Employed a novel timescale-decomposition methodology to analyze climate anomalies.
• Differentiated contributions of El Niño, climate change, and other climate variability (year-to-year, decadal).

Main Results:

• Extreme climate anomalies were driven by a combination of climate signals across multiple timescales.
• Brazilian drought (2013-2015) primarily resulted from year-to-year and decadal variability, with minimal long-term trend contribution.
• Warm temperatures (2014-2015) stemmed from the compound effect of climate change, decadal, and year-to-year variability.

Conclusions:

• ZIKV response strategies in Brazil during the 2015-2016 El Niño event may need revision due to expected rainfall changes (La Niña).
• Sustained warm temperatures are anticipated due to long-term and decadal climate signals, impacting future ZIKV risk.