Comparative Genome Analysis of All Nine African Horse Sickness Serotypes Isolated From Equine Fatalities in Kenya and South Africa.

The research article covers a detailed genome analysis of all nine African Horse Sickness (AHS) serotypes found in equine fatalities in Kenya and South Africa, comparing these to the strains previously used in vaccines in order to evaluate their efficacy and safety.

Background of African Horse Sickness (AHS)

• AHS is an endemic viral disease affecting equids, particularly prevalent in sub-Saharan countries. The disease is caused by a virus from the genus Orbivirus, family Reoviridae.
• The virus which causes AHS is known as the African horse sickness virus (AHSV). Its genome comprises ten double-stranded RNA (dsRNA) segments that collectively encode for seven structural and four nonstructural proteins.
• An inactivated AHS vaccine, containing all the nine serotypes, has previously been produced at the Central Veterinary Research Laboratory (CVRL) in Dubai. The efficacy and safety of this vaccine have been substantiated in the past.

Study Methodology and Sample Collection

• The study encompassed the collection of 102 samples over the past 20 years from horse fatalities in seven different parts of Kenya.
• All the nine AHSV serotypes were isolated from these samples. The study also utilized the nine AHSV serotypes isolated in South Africa.
• The vaccines produced by CVRL are in use in select African countries, thus making the genome comparison study of the isolated AHSV serotypes highly significant.

Genome Comparison and Findings

• The study carried out a genome comparison of the isolated nine AHSV serotypes from horsing fatalities in Kenya and South Africa.
• Finally, the research confirmed the hypothesized serotypes of the newly sequenced AHSV field strains from Kenya. These field strains show substantial sequence homologies with recently isolated AHSV field strains.

Implications of the Study

• These findings may have important implications for the ongoing development and efficacy evaluation of vaccines against AHSV. It emphasizes the need for vaccines to evolve according to the shifts and changes in viral genomes.
• The comparison of the genome sequences can provide valuable insight into the evolution of the virus and offer a better understanding of its diversity, which can assist in improving preventive measures and treatments.