In vitro comparison of acyclovir, ganciclovir and cidofovir against equid alphaherpesvirus 3 and evaluation of their efficacy against six field isolates.

The research article is about testing three antiviral compounds (acyclovir, ganciclovir and cidofovir) in fighting the Equid alphaherpesvirus 3 (EHV3). The findings suggest ganciclovir as the most potent antiviral compound to reduce EHV3 replication.

Objective of the Study

• The research aimed to explore the efficacy of three antiviral compounds – acyclovir, ganciclovir, and cidofovir – in curbing the Equid alphaherpesvirus 3 (EHV3), responsible for Equine Coital Exanthema (ECE). These compounds have previously been effective against alphaherpesviruses that affect humans and animals.

Background Information

• EHV3 instigates ECE, a highly contagious venereal disease characterised by the emergence of papules, vesicles, pustules, and ulcers on the external genitalia of mares and stallions. After infection, the virus often remains latent with the potential for reactivation and subclinical re-excretion.
• Currently, no vaccines are available for ECE, and prevention strategies include clinical examination of mares before mating. This segregation based upon clinical signs does not completely eliminate contagion risk, thus necessitating a specific EHV3 treatment.

Methodology

• To verify the efficacy of the three antiviral compounds against EHV3, three parameters were analyzed in vitro: reduction of plaque size, reduction of plaque number, and reduction of viral production. The in vitro assessment helps model the potential impact these compounds could have within an organism.
• A parallel investigation was also conducted where effectiveness of the compounds, at an optimum concentration, was tested for six different EHV3 field isolates from Argentina. This aspect helps to generalize the findings beyond a solitary strain of EHV3.

Key Findings

• Based on the research, ganciclovir emerged as the most potent antiviral compound in reducing EHV3 replication in vitro. This indicates its potential as a candidate for prevention and treatment of ECE in mares and stallions.