Preventing the spread of swine influenza

March 16, 2017

With the current news topics of emerging strains of swine1 and avian influenza2 spreading throughout North America, it is important to review the influenza virus, what it can do if it enters your farm, and how you can prevent it from spreading.

What is influenza?

The commonly known influenza virus (H1N1) was first identified and largely stayed unchanged for over 80 years.3 However, in 1998, researchers identified a new strain of influenza virus (H3N2) that developed from multiple species, including humans and birds that could infect pigs.3 Since the immune system could not recognize the new proteins, the new strain was able to enter the herd population undetected.

Over the course of the next two decades, the influenza virus continued to change, requiring veterinarians and university pathologists to isolate the viruses and create herd-specific, autogenous vaccines since commercial vaccines were not providing adequate immune responses on the farm.4 The challenge continues to this day to find effective and economic ways to prevent the spread of influenza.

What does influenza do on the farm?

Swine influenza virus (SIV) is thought to be one of the top three respiratory challenges in pigs due to its productivity loss and almost constant presence on hog farms.5 When it comes to phases of production, SIV can impact the breeding herd the most, causing over $10 per pig in lost productivity.6 Once a virus has infiltrated the breeding herd, the financial impact will continue to be seen down the line in nurseries and finishers until a PCR-negative piglet is produced.7

Zoonotic pressures also place a concern on the farm with SIV. Though it is more common for humans to pass the flu to pigs, it is possible for some strains to pass from pigs to humans. When farm personnel become infected, there is a risk of infecting other herds via human movement and contact. But cross-contamination isn’t the only issue when humans have the flu. Productivity dramatically decreases which could allow other pathogens to infiltrate and take up residency within a herd.

How can you prevent influenza from spreading?

Prevention begins with biosecurity. When a biosecurity defense program is complete, there is a reduction in the chance of an outbreak and prevent an outbreak from spreading. A biosecurity defense program should include at least two focuses: humans and pigs.

As evidenced through the porcine epidemic diarrhea virus (PEDv), humans can be an integral part in either the spread, as well as the prevention of disease. Practicing preventative hygiene measures, including shower-in/shower-out, washing your hands and using hand sanitizer, wearing personal protective wear, properly utilizing boot baths, and not touching your eyes, nose and mouth can help prevent oneself from becoming infected or infecting others.

A comprehensive farm biosecurity plan can also reduce the risk of pigs becoming infected. Adhering to the clean/dirty line when external deliveries such as feed, propane, pick-up and drop-off livestock trucks, and product deliveries can help limit the farm-to-farm risks. Proper and frequent cleaning and disinfecting of these clean/dirty areas will help control on and off farm spreading.

In the fight to prevent disease, Neogen is there to provide a full arsenal of products. From cleaners and disinfectants such as Barnstorm™ and Synergize™, to rodent and insect control, Neogen is the global biosecurity leader in animal health and your partner in food safety from the farm gate to the dinner plate.

For more information on Neogen’s biosecurity program, click here.


  1. Detmer, Susan. "New H1N2 Influenza Strain Shows Signs of Spreading." Western College of Veterinary Medicine. Farmscape, 07 Mar. 2017. Web. 09 Mar. 2017.
  2. Winterbottom, Jo. "Bird flu found in Tennessee chicken flock on Tyson-contracted farm." Reuters. Thomson Reuters, 06 Mar. 2017. Web. 09 Mar. 2017.
  3. Connecting the dots between swine influenza A virus surveillance and vaccines. Vincent, A, Anderson, T, Rajao, D, Campbell B, AASV Proceedings 2014. Pp527-532.
  4. Characterization of a newly emerged genetic cluster of H1N1 and H1N2 swine influenza virus in the United States. Virus Genes, 39:176-185. Genotype patterns of contemporary reasserted H3N2 virus in US swine. J GenVirol. 2013 Jun;94(Pt 6): 1236-41. Do:10.1099/vir.0.51839-0.
  5. Holtkamp D, Rotto H, Garcia R. The economic cost of major health challenges in large U.S. swine production systems, in Proceedings. Amer Assoc Swine Vet Conf 2007; 85-89.
  6. Donovan TS. Influenza isolate selection methodology for timely autogenous vaccine use, in Proceedings. Amer Assoc Swine Vet Conf 2008; 557-561.
  7. USDA. 2008. Part IV: Changes in the U.S. Pork Industry, 1990-2006. USDA-APHIS-VS, CEAH. Fort Collins, CO.

Category: Agriculture, Animal Safety, Swine, Veterinary, Sanitation & Hygiene, Veterinary Instruments