Synchronized dynamics of dengue across the Americas

Area of Science:

• Epidemiology
• Climate Science
• Public Health

Background:

• Dengue is a widespread tropical disease with poorly understood regional dynamics.
• Understanding dengue's seasonal and multiannual trends is crucial for effective control.

Purpose of the Study:

• To examine seasonal and multiannual dengue trends across the Americas.
• To identify underlying mechanisms driving regional dengue dynamics.
• To assess the synchrony and spatial coherence of dengue epidemics.

Main Methods:

• Utilized monthly dengue surveillance data from 241 subnational locations in 14 countries (1985-2018).
• Employed wavelet analysis to identify seasonal (8-16 months) and multiannual (17+ months) dengue patterns.
• Assessed spatial and temporal coherence of dengue cycles, comparing them with climate variables (temperature, rainfall) and El Niño Southern Oscillation (ENSO).

Main Results:

• Identified strong regional synchrony in dengue dynamics at both seasonal and multiannual scales.
• Seasonal dengue trends correlated with local climate patterns and neighboring locations' dynamics.
• Multiannual epidemics showed high synchrony across vast distances (up to 10,000 km) with a 6-month lag, influenced by climate variability and human movement.

Conclusions:

• Dengue dynamics in the Americas are regionally synchronized, not isolated to individual countries.
• Regional climate variability and human movement are key drivers of widespread dengue epidemics.
• Findings support enhanced early warning systems and emphasize the importance of international collaboration for dengue preparedness and response.