Investigation of equine influenza virus in two geographical regions of Pakistan.

This research article examines the level of prevalence (seroprevalence) of the equine influenza virus (H3N8) in two regions of Pakistan where vaccination is not common practice. Findings indicate that the virus is present in equine species in these areas, despite no strain being isolated from nasal swabs.

Objective and Methodology

• The main goal of this study was trying to clarify the extent of the equine influenza virus (H3N8) in two distinct geographical areas of Pakistan, particularly in places where vaccination is rarely done.
• In the scope of this research, 315 animals from the Equidae family were surveyed. Both blood samples and nasal swabs were collected from each animal.
• Two kinds of tests were conducted – ELISA (Enzyme-Linked Immunosorbent Assay) and Hemagglutination Inhibition – to determine whether these animals had the virus or antibodies against it.

Results of the study

• The seroprevalence of Equine Influenza Virus (EIV) was found to be 10 and 8.39 in the two studied districts meaning that about 8 to 10 percent of animals tested positive for exposure to EIV.
• Out of the 29 ELISA positive sera, 24.1% demonstrated antibodies against the H1 strain, and the remaining 75.9% against the H3 strain of influenza.
• When further categorized into species, the antibody titer (concentration) against H1 strain was 7.5 in horses and 9.0 in donkeys, while mules showed no antibodies. For the H3 strain, horses, donkeys, and mules showed antibody titers of 7.12, 6.9, and 6.0 respectively.
• Intriguingly, no strain of the influenza virus was isolated from the nasal swabs, despite high antibody titers of H1 and H3 in the blood samples of the same animals.

Conclusion

• The study concludes that influenza viruses are present in equine species in the studied areas of Pakistan. It also emphasizes the importance of sustained surveillance to prevent future outbreaks and keep their spread under control.