In 1988, a new swine virus (H3N2, if you want to get technical) developed in the United States, brewing first in pregnant sows in North Carolina, then spreading to hog herds in Texas, Iowa and Minnesota.
Like the current H1N1 virus, H3N2 contained genes from swine, human and avian influenza viruses. Like all good viruses, it refused to remain static and mixed with classic swine flu virus (H1N1) and evolved into yet another virus, H1N2, which causes respiratory disease in swine.
Pigs, unfortunately, serve as a “mixing vessel” for genetic reassortment of viruses.
The finger-pointing is all over the place when people start looking for the root of the current H1N1 virus spread. The truth is that influenza viruses are generally host-specific and rarely establish themselves in another host species, but genes from those viruses can be transmitted between species. For example, 73 percent of turkey flu viruses contain genes of swine origin. And swine flu viruses have likely acquired genes from human strains.
Look at the genetic relationships of these co-circulating viruses and you see a family tree-like chart, noting evolution from similar ancestors.
Most livestock producers take precautions to prevent the spread of disease. (That’s why you shouldn’t take it personally if you ask to go into a hog or poultry barn and the farmer looks at you like you’re nuts. No, he doesn’t have anything to hide, he’s just being safe. You may not have the flu, but you could be harboring a strain that could be passed on to his pigs.)
What we humans need to realize is that this is a flu strain, just like any other flu strain. As such, you can avoid it (or avoid spreading it) with some common sense.
– If you’re sick, stay home and minimize your contact with others.
– Cover your nose and mouth with a tissue when you cough or sneeze.
– Wash your hands. Often.
– Don’t touch your eyes, nose or mouth.
If you’re a hog or poultry producer, now’s a good time to reassess your buildings, particularly your ventilation system, experts say.
– Control traffic on your farm. You can protect everyone’s health — human and animals alike — by limiting the chance of disease transfer or further gene spread.
– Follow strict sanitation practices. Even if you don’t have a shower-in/shower-out setup, make sure you and your employees are practicing good personal hygiene. And if you’ve got different barns, consider wearing clean clothing and boots in each one (I hear you, it’s a pain, but dealing with a case of swine flu on your farm would be worse).
– Consider grouping animals by age (younger animals haven’t fully developed their immune systems).
– Take the time to watch your herd or flock every day.
– Now’s not the time to scrimp on vaccinations.
I’m sure we have not heard the last of the H1N1 virus or related gene reassortments. But it’s not the time to panic. It’s the time to use your head and common sense.