Bob Mikesell, Ph.D.
Senior Instructor
Department of Dairy and Animal Science

Introduction

In light of the H1N1 (formerly known as swine flu) virus outbreak, consumers should have an understanding of the influenza virus from a pork producer perspective, and the steps that US swine producers routinely utilize to keep pigs healthy.

Influenza background from the pork industry perspective

• Pork producers have occasionally battled an influenza virus that is transmitted among pigs. Pig influenza within a swine herd generally presents as a relatively mild respiratory disease and treatment is initiated in consultation with the herd veterinarian.

• Very rarely, swine influenza can be transmitted from pigs to humans (zoonotic transmission).

• Although rare, the Centers for Disease Control reports several past cases where an influenza virus originating in swine passed from human to human.

• It appears as if pigs can be infected from humans who are shedding the current H1N1 virus, as evidenced by a case in Canada.

Many routine practices employed by US swine producers prevent, not only swine influenza, but other diseases as well.

• Most animals are housed in like-aged groups to reduce disease transfer from older pigs to younger pigs. Buildings are temperature-controlled and scientifically designed to keep pigs clean, safe and protected from predators, disease and extreme weather.

• Producers utilize all-in-all out production where a building is completely emptied, washed, and disinfected between groups of pigs. This practice serves as a further measure to break disease cycles on pig farms.

• As part of the National Pork Board’s Pork Quality Assurance (PQA) program, pork producers develop and follow a herd health plan in cooperation with a licensed veterinarian. The herd health plan may include influenza vaccine among other disease prevention vaccinations. Most US pork packers require producers to maintain PQA certification.

• Producers practice biosecurity to prevent diseases from traveling into or out of a facility. In the event of a disease outbreak, pigs confined in an enclosed building are much easier to quarantine than are pigs housed in the open.

Conclusion

Contemporary swine production practices and biosecurity measures are well suited to reduce the spread of diseases, including the current H1N1 influenza virus. Confined production greatly reduces the opportunity for conventional and zoonotic disease transfer because of limited animal-to-animal and animal-to-human contact, and serves as an effective disease isolation mechanism when diseases do occur.