Influenza A: Transmission of the H1N1 influenza virus between pigs and farmers has been confirmed

A study by the University of Minnesota conducted a risk assessment of interspecies transmission of the influenza A virus from pigs to farmworkers. The findings regarding the spread of this zoonosis are unequivocal.   This study showed that interspecies transmission of the influenza A (H1N1) virus between humans and pigs does indeed pose a threat to both animal and human health. It was found that up to 57% of the farmworkers monitored during this research tested positive at least once during the study period (eight weeks during the 2017–2018 and 2018–2019 flu seasons). More importantly, some farm workers were asymptomatic carriers of the swine-origin virus in their nasal passages and were infected with the human-origin virus, making them capable of transmitting it to pigs. There is therefore a very real public health risk associated with contact between humans and pigs. This must be taken into account in policies for the prevention of zoonotic infections with pandemic potential. To reach these conclusions, the University of Minnesota monitored 58 farm workers during the 2018 and 2019 winter seasons in the U.S. Midwest. They came from seven different pig farms. The protocol called for two daily nasal swabs, twice a week for eight weeks; the first was taken in the morning before the workday began, and the second in the evening upon leaving the farm. In addition, a questionnaire was provided for them to report any symptoms (fever, headache, cough, sneezing, muscle aches, etc.). For the pigs, samples were collected midway through and at the end of the technicians’ sampling period. An rRT-PCR test was then performed on all samples collected for both the human and swine viruses.