Epidemiological investigation and analysis of the NS5B gene and protein variability of non-primate hepacivirus in several horse cohorts in Rio de Janeiro state, Brazil.

This study is about the prevalence, risk factors and genetic variability of the Hepacivirus A, found in horses and donkeys, in various horse cohorts throughout the state of Rio de Janeiro, Brazil. It examines potential risk factors and the diversity of the virus’s NS5B gene and protein.

Overview of Hepacivirus A and its Importance

• The Hepacivirus A, also known as non-primate hepacivirus, is found in horses and donkeys and is closely related to the human Hepatitis C Virus (HCV).
• Studying this virus in equines (horses and donkeys) provides a practical large animal model for understanding the therapy, pathogenesis and prophylaxis of HCV in humans.
• Despite considerable research efforts, important issues including risk factors, virus distribution and genetic variability of Hepacivirus A have not been fully understood.
• This knowledge gap also has implications for equine welfare.

Aim and Approach of the Research

• The study aimed to investigate potential risk factors associated with Hepacivirus A infection among different horse cohorts in Rio de Janeiro and to assess the variability of the viral NS5B gene and protein.
• The researchers detected Hepacivirus A RNA in horse cohorts from all geographical regions of the state irrespective of the horse’s breed or activity.
• To understand the connection between risk factors and infection, researchers considered parameters like geographical location and age of female horses.

Findings from the Study

• The presence of Hepacivirus A varies across the state ranging between 4.0% and 27.5%.
• Risk factors such as geographical location and age of female horses showed a significant association with the presence of the virus RNA.
• A subtype of virus, subtype 2, was found circulating in all regions of the state.
• The NS5B gene sequences grouped according to geographical origin whereas NS5B fragments did not permit such grouping.
• Notably, the predicted NS5B protein displayed high conservation, especially in the thumb domain.

Conclusions and Future Directions

• The study suggests a likely connection between reproduction practices and the spread of the virus, given the higher frequency of Hepacivirus A RNA detection in horses bred for reproduction as well as in young females.
• Additional studies are needed to provide more insights into the distribution of this genetically conserved hepacivirus.