The crab hole mosquito blues.

Area of Science:

• Veterinary Virology
• Epidemiology
• Molecular Biology

Background:

• Venezuelan equine encephalomyelitis (VEE) has caused recurrent epizootics in South America since the 1920s.
• VEE virus was first isolated in 1937, distinguishing it from North American equine encephalomyelitis viruses.
• Distinct epizootic and sylvatic strains of VEE virus were identified in different ecosystems.

Observation:

• Epizootic VEE virus strains were classified as subtype I (variants A/B, C).
• Sylvatic (enzootic) VEE virus strains were classified as subtype I (variants D, E, F) and subtypes II, III, IV.
• In 1969, VEE variant I-A/B spread from South America to Central America, affecting multiple countries.

Findings:

• The 1969 VEE outbreak represented an unprecedented geographic expansion of the virus.
• This epizootic event involved the movement of VEE virus from South America to Central America and into Mexico and the United States.
• The VEE outbreak continued to affect equids and humans until 1972.

Implications:

• Understanding VEE virus ecology and strain diversity is crucial for predicting and controlling future outbreaks.
• The 1969 event highlights the potential for rapid, long-range dissemination of VEE virus.
• Effective surveillance and response strategies are necessary to mitigate the impact of VEE on animal and human health.