Although documentary evidence is lacking, it has long been suspected that epidemic human strains of influenza virus may, at times, emerge from animal reservoirs.
There is indeed some suggestion that, historically, at least one period of human epidemic (1880-1890) may have arisen from horses. Natural transmission of current equine influenza strains to man has not been documented, although infection in man with equine strains can be produced experimentally.
To assess the potential of current equine influenza strains to produce human disease, investigators at the National Institute of Allergy and Infectious Diseases studied the effect in human volunteers and horses of strain A/equine 2 virus.
Reporting their findings to the annual meeting of the American Society for Microbiology, Robert H. Alford, MD, said sporadic human infection and mild illness due to the equine virus may occur but that it does not appear to have epidemic potential for man.
"However, no protection