Swine Influenza - CDC Guidance

Swine influenza (swine flu) is a respiratory disease of pigs caused by type A influenza virus that regularly causes outbreaks of influenza in pigs. Swine flu viruses do not usually infect humans, but rare human infections have occurred. Swine flu viruses can cause high levels of illness in pig herds, but cause few deaths in pigs. Swine influenza viruses can circulate among swine throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks in humans.

Transmission of swine influenza viruses from pigs to people is thought to be spread primarily via large infectious droplets expelled by a sick infected pig during coughing or sneezing to a person in close contact with infected pigs. There also is indirect evidence to suggest that swine influenza viruses can be transmitted to people through contact with infected pigs or with surfaces recently contaminated with swine influenza viruses (e.g. touching pigs or handling material contaminated with pig secretions or feces, and then touching one’s mucous membranes). A third possible mode of transmission is via inhalation of small particulates containing swine influenza virus. The relative contributions of these three modes of transmission to the spread of swine influenza viruses to humans are not fully understood.

Basic Infection Control to prevent transmission of influenza viruses from pigs to people and from people to pigs:

CDC Interim Guidance for Workers who are Employed at Commercial Swine Farms: Preventing the Spread of Influenza A Viruses