Wells, Diana L., Hopfensperger, Daniel J., Arden, Nancy H., Harmon, Maurice W., Davis, Jeffrey P., Tipple, Margaret A., and Schonberger, Lawrence B.
The deadly influenza of 1918-1919 is believed to have been caused by the swine influenza virus (SIV) or a related virus. This disease affects swine and turkeys, and is a common cause of respiratory disease among these animals during the winter. Since the isolation of SIV from a human subject in 1974, at least 11 other outbreaks of the infection have been noted. The fear of another pandemic led to the massive swine flu vaccination effort by the federal government in 1976 and 1977. In a recent case in October 1988, a pregnant woman and her husband attended an agricultural fair. A few days later, both became ill. The woman was put on a mechanical ventilator; a healthy baby was born, but the woman died of respiratory arrest. The SIV virus of the type seen in ill swine in Wisconsin was detected. Through interviews conducted later it was determined that 40 to 60 percent of swine exhibitors had influenza-like illness (ILI) during the fair. The dead woman had been infected either directly from the pigs, or by transmission from the pigs to her husband, and then to her. Existing regulations for agricultural fairs in Wisconsin bar infected animals from being exhibited. However, SIV infection is transmitted rapidly, and swine who become ill after arrival may already spread the infection to other swine. It may be necessary to close pig barns to the public as soon as infection is detected. Priority should be given to the development of a SIV vaccine for swine; one already exists for turkeys. This would not only benefit the farmers, who lose money on sick swine, but all humans who come in contact with the pigs. (Consumer Summary produced by Reliance Medical Information, Inc.)