It’s been just over two years since the 2009 H1N1 influenza virus shook your world and disrupted U.S. pork’s global markets. But even in that short time, the impacts have easily slipped from one’s mind. There are so many other issues that you have to deal with today and influenza is so commonplace that it can be hard to give it priority status. However, it needs to be a priority, and while pigs can encounter influenza viruses year-round, it’s flu season again for people.

“The 2009 H1N1 influenza pandemic highlighted the importance of interdisciplinary approaches in addressing emerging issues in regard to influenza viruses and their interspecies relations,” says Carlos Andres Diaz, DVM, doctoral candidate, University of Minnesota College of Veterinary Medicine. Part of that approach is to address influenza in the human population on the farm, especially those who interact with the pigs.

In 2009, it was people who exposed pigs to the H1N1 virus, and the potential exchange between humans, birds and pigs, accompanied by reassortant prospects, are what require your attention now.

Each year about this time the U.S. Department of Health and Human Services, medical doctors and even local pharmacies work hard at reminding the public about the importance of and need for flu immunizations, yet last year just 43 percent of the population got vaccinated. Pork industry leaders have been trying to drive home the importance of ensuring that the people on pig farms not only get seasonal flu shots but also ramp up basic biosecurity protocols to minimize virus exposure.

So, how’s that going? Diaz and a team of University of Minnesota researchers conducted a survey reflecting actions for the 2010/2011 flu season. In all, 310 surveys were completed, made up of swine production personnel, producers, farm owners, researchers, practitioners and other industry participants. Representation of actual on-farm production personnel was limited (7 percent); however, 27 percent of survey participants spent 10 hours or more each week working directly with pigs. The average age of participants was 45.6 years, and 75 percent were males.     

For the total survey group, 57 percent said they always receive the annual influenza vaccine. Not bad — better than the general public — but given that the group actually skewed toward highly educated individuals with an animal health bias, the results are a bit disappointing. One can comfortably suspect that the general pork production population scores a lower vaccination rate.

Among the reasons respondents gave as to why they didn’t get vaccinated: Do not have time (17 percent), not concerned about influenza infections (16.2 percent), not convenient to receive the vaccine (14 percent), prefer natural exposure to the influenza virus (9 percent), did not see any benefit to vaccination (8 percent). Also, 6.5 percent were worried about side effects, 5.5 percent said the vaccine wasn’t available and 5 percent thought the vaccine wasn’t effective. Of those respondents who did not get vaccinated, 10 percent said they could not be convinced to receive it in the future.

What would convince the other 90 percent? If the vaccination process was convenient, free or required by employer; pandemic or new strains emerged; the vaccine had no side effects, was more effective and it could be administered other than through an injection.

Interestingly, only 47.2 percent of respondents who worked with pigs less than five hours a week got vaccinated, while 66.9 percent who spend 10 or more hours with pigs did so. In reality, the pig interaction time shouldn’t be an influencing factor, and even office staff should be part of a vaccination regimen.

So, what does all this mean to you, your workers, family and business? It means influenza vaccinations for people that touch your pigs directly or indirectly should be a priority. It starts with you; lead by example and get vaccinated. Then explain the situation to your staff and family, and make it easy for them to get a flu shot. Depending on the number of people, a public nurse may come to your site to conduct a vaccination clinic. Allow workers time off to get a flu shot and reimburse them for the costs, if necessary. Don’t make it optional; require that everyone in and around your business is vaccinated seasonally.

“Influenza is a ‘shared disease’ and one of the best examples of zoonosis,” says Montserrat Torremorell, DVM, Leman chair in swine health and productivity at the University of Minnesota. “The wild card is people and the risk of people infecting pigs.”

While the direct cost of influenza to producers needs to be quantified, $10 per pig infected is not unrealistic, she says. As for indirect costs, there are the antibiotics used to address secondary infections, which continue to raise concerns among consumers. Growing in importance is the potential backlash from foreign markets. It’s worth remembering how the 2009 H1N1 influenza episode impacted U.S. pork exports and U.S. hog prices. With 22 percent — and rising — of  U.S. annual production headed overseas, future impact could be even harsher.

“The problem won’t get any easier,” Torremorell says. “If anything, controlling flu will get more challenging.” 

Complacency is the Enemy

Influenza is an opportunistic disease, and it’s in your best interest to limit those opportunities. Beyond ensuring that the people on your farm get their seasonal flu shots, there are other steps to put in place.

• Start with hygiene. Showering in and out may be part of your system’s requirements, but regular and thorough hand-washing too often gets overlooked. It may seem simplistic, but it needs to be a priority. 

• Commit to facility-specific clothing and footwear, and consider requiring the use of personal-protective equipment, especially during flu season. 

• Review your sick-leave policy and require that sick people (fever, coughing, body aches and sometimes vomiting and diarrhea) stay home. In people influenza, virus shedding is at its highest when clinical signs are most severe, but people can shed virus for three to seven days after symptoms subside.

• Bird-proof hog barns and prevent access to feed. “Wild birds and waterfowl, especially ducks, are natural reservoirs of the virus, so keep them away,” says Montserrat Torremorell, DVM, University of Minnesota. “Also avoid contact with their feathers, feces and the water systems connected to them (lagoons, drinking water and such).”

• Observe pigs daily, looking for signs of influenza (sneezing, coughing, labored breathing, nasal discharge). If you suspect exposure to influenza virus, contact your veterinarian immediately.

Finally, if you’re not already involved with the national swine influenza surveillance program, talk to your veterinarian. “We need to support the national and international surveillance efforts,” Torremorell says. “We need to prepare for the next round.”