Complex Epidemiological Dynamics of Eastern Equine Encephalitis Virus in Florida

Area of Science:

• Veterinary Entomology
• Epidemiology
• Molecular Virology

Background:

• Eastern equine encephalitis virus (EEEV) causes severe disease in horses and humans.
• Florida is a significant origin of EEEV epidemics in the United States.
• Understanding EEEV dynamics in Florida is crucial for public health.

Purpose of the Study:

• To characterize the epidemiological and evolutionary dynamics of EEEV in Florida.
• To identify seasonal patterns and regional variations in EEEV activity.
• To investigate the genetic diversity and dispersal of EEEV within Florida.

Main Methods:

• Analysis of sentinel chicken seroconversion rates from 2005-2016.
• Phylogenetic analysis of EEEV genome sequences (1986-2014) from various hosts and regions.
• Correlation analysis between genetic variation and host source.

Main Results:

• Significant seasonality of EEEV activity observed in Florida, with regional variations.
• Extensive genetic diversity and spatial dispersal of EEEV across Florida.
• The Panhandle region showed less seasonality and more viral clustering, suggesting a potential source.
• No significant association found between EEEV genetic variation and host source.

Conclusions:

• EEEV exhibits complex epidemiological dynamics in Florida.
• The Panhandle region may serve as a persistent source of EEEV with year-round transmission.
• Findings support targeted control strategies for EEEV and other mosquito-borne diseases.