Venezuelan equine encephalomyelitis and African horse sickness. Current status and review.

This research article discusses the threat posed by two arthropod-borne diseases, Venezuelan equine encephalomyelitis (VEE) and African horse sickness (AHS), to the livestock industry, specifically in the North American and Caribbean regions. The authors underscore the need for vigilance, preparedness, surveillance and research in order to prevent these diseases and protect the world agricultural marketplace.

Detailed Explanation of the Article

Arbovirus Diseases and Livestock

• The research deals with ‘arbovirus’ diseases; a group of viruses that are transmitted by arthropods, such as mosquitoes and ticks. These diseases can have a serious effect on livestock and thus a significant impact globally.
• The authors highlight the challenge in preventing such diseases from being introduced into new areas, and controlling them once they have been introduced. They stress that this requires cooperation from all involved parties, including the livestock industry, regulatory agencies and researchers.

Prevention Versus Zero Risk

• The authors suggest the best way to protect livestock industries is to prevent the introduction of exotic diseases. However, they also add that a ‘zero risk’ strategy, involving complete restriction on animal imports and exports, is not feasible in the modern interconnected world.
• They propose a balanced approach that makes scientifically informed and fact-based regulatory decisions. This must be combined with vigilance and preparedness, as well as surveillance and research.

Concerns About VEE and AHS

• The two specific diseases that the authors focus on are Venezuelan equine encephalomyelitis (VEE) and African horse sickness (AHS), which they note are of current concern to the livestock industries and regulatory officials in North America and the Caribbean.
• They discuss the history of VEE outbreaks in equines in the Western Hemisphere, while mentioning that recent epizootic activity has not been documented. Despite this, they signal that equine nonpathogenic VEE virus subtypes do exist in tropical countries of the hemisphere, and the relationship between these and severe disease-causing virus subtypes remains unclear.
• The authors also share data on AHS, a disease confined mainly to Africa, the Middle East, and the Indian subcontinent, but had outbreaks in Spain in 1966 and between 1987-1990.
• The recurrence of AHS in Spain over the last four years has raised concerns about the potential introduction into vector species (organisms that transmit diseases from one host to another) and equines in the Western Hemisphere.

Conclusion

• The article concludes by stressing the importance of addressing current VEE and AHS virus activity and the potential for outbreaks in the Western Hemisphere.