Assessment of transmission of Mycoplasma hyopneumoniae by personnel

Respiratory disease in swine is a major economic concern for producers around the world. Enzootic pneumonia, one of the most important chronic diseases in swine, is caused by Mycoplasma hyopneumoniae. Direct contact with infected pigs has been established as the chief route of transmission, constituting the main point of entry of the agent into the herd. Latently infected animals, aerosol spread, and fomites are alternative routes of infection of naive swine herds. Although the role of people acting as mechanical vectors in the transmission of pathogens between farms or groups of pigs has not been clearly defined, there are reports of isolation of foot-and-mouth disease virus, swine influenza, Pasteurella multocida, and porcine reproductive and respiratory syndrome virus from humans exposed to infected swine. In this case, M hyopneumoniae was not transmitted during a 20-week period when personnel weekly contacted susceptible pigs in a naive herd immediately after close contact with pigs in an infected herd. Personnel used a standard hygiene protocol before entering the uninfected farm.