It has long been known that avian and swine strains of flu can spread to humans, with avian strains appearing to be more dangerous than swine strains.
"The concern is that swine viral strains could adapt into a form that results in efficient human-to-human transmission," said Dr. Joan Robinson, a University of Alberta professor and lead author of the study. "Early recognition that swine strains are becoming more virulent might expedite both implementation of ideal infection control precautions for symptomatic cases and vaccine development."
Robinson said rather than livestock farm workers being responsible for recognizing their own flu symptoms, there should be a public health program in place that leads to specific measures if an unexpected number or severity of cases of flu-like illness occur in farmworkers. No health program targeting swine workers currently exists, she noted.
The study was reported in the journal Emerging Infectious Diseases.