[Equine influenza in Czechoslovakia during the 1973 epizootic].

This research focuses on the outbreak of equine influenza that occurred in Czechoslovakia in 1973 and was caused by the A equi 1/Praha 56 virus. The study highlights the effectiveness of the french Grippeguin vaccine, as well as interesting anomalies observed in unvaccinated mares and young foals.

Epidemiology of the Epizootic and Initial Detection

• The document discusses an expansive outbreak of equine influenza in Europe that also affected Czechoslovakia. It commenced from Slovakia, where equine cases were isolated following international travel, and subsequently disseminated through racehorses nationally.

Identification of the Infectious Agent

• Veterinary scientists utilized serological testing, specifically the IH (immunohistochemical) test, to identify the causative virus. The strain was found to be A equi 1/Praha 56, reinforcing this as the etiological factor of the epidemic.

Interception and Cure

• The researchers applied the Grippeguin vaccine, imported from France, to intervene with the epidemic. The vaccine was found effective, and this incident reaffirmed the utility of vaccination in safeguarding horses from equine influenza.

Incidental Findings and Unanswered Questions

• Likewise noteworthy were two mares on one farm that did not exhibit clinical signs of the disease despite not being vaccinated and being in the epicenter of the infection.
• Fascinatingly, these mares were cohabitated with one-year-old foals that had been immunized against equine flu prior to being transported to a training stables in autumn 1972.
• The disease also did not manifest in their offspring (aged three and five months) who were situated in the heart of the infection zone.
• This observation brings the understanding of immunity to equine flu into question, indicating that natural resistance or maternal antibodies may play a larger part in immunity than previously understood.