February 2015
From the State Vet's Office

Biosecurity: Managing the Risks of Biological Hazards

The term biosecurity was first used in reference to taking precautions to keep laboratory workers and medical personnel protected from the biological hazards they often come in contact with on their jobs. Biological hazards include bacteria, viruses, some disease-causing fungi and an occasional prions. For this article, we will either use the term biological hazards or germs. Biosecurity has now come to refer to protecting life from biological hazards. That may be a little contradictory depending on what perspective you are reading this from. An example is that we kill mosquitoes to protect against the encephalitis viruses they carry and spread. I guess if you are the mosquito you could argue that your life was not protected in that instance. Anyway, you get the point. Therefore, a biosecurity program simply identifies risks then comes up with actions or a plan to minimize the risk. And if infection cannot be prevented, the three "Rs" come into play. I am not referring to reading, ‘riting and ‘rithmatic. (Apparently the three "Rs" in school pretty much disregard the one "s" – spelling). Referring to disease, the three "Rs" are recognition, response and recovery.

A few years ago, our state worked with USDA Veterinary Services to dramatically reduce the incidence of Johne’s disease in cattle. Johne’s disease causes some pretty bad damage to the cow’s gut and results in constant diarrhea and weight loss. Then you have those subclinical cases of Johne’s disease that fly below the radar and cost the producer tons of money by lowering milk production, reproductive efficiency and productivity in general. One of the components of the Johne’s Disease Program was to have your veterinarian do a risk assessment. Johne’s disease does not parachute onto a farm from the sky or anything like that. It arrives on the farm inside an infected cow. And when it gets on a farm, it is very difficult to completely squelch the threat of the disease. So the producer and the veterinarian brainstorm on ways to keep the disease off the farm. What we realized was that the principles of biosecurity applying to Johne’s disease will reduce the risk of many biological threats. I will get back to some specifics about that later.

I don’t know about y’all, but every now and then I will have a message on my answering machine telling me I have been recommended to have a home security system installed free. That’s about where I push the erase button. That is not to say I am against home security systems (and for any potential burglars that may be reading this, I may or may not have a home security system with the 9 mm and .40 cal notwithstanding!). The security systems advertised for homes, along with some good common sense practices, will minimize the chances of a house being burglarized. Practices such as keeping doors and windows locked, keeping entrances well lighted and keeping shrubs near windows and entrance areas trimmed so no one can hide in them can certainly make it difficult for an unwanted intruder to come into your home. And if your security measures are breached then the alarm system facilitates early recognition and response.

A biosecurity plan is not all that different from a home security system. It first uses a risk assessment to identify areas of vulnerability. Then it implements steps to keep germs out. And finally, there is a surveillance component that, in case security is breached by unwanted germs, rapid recognition and response are possible.

We often think of biosecurity to prevent some sort of terrorist attack on animal agriculture or to protect against some foreign animal disease. Those are certainly considerations and good reasons to practice good biosecurity for your herd or flock. It may actually be more important on a day-by-day basis to prevent the everyday BVD in cattle or mycoplasmosis in backyard flocks. From where I sit, I hear about farmers every week who pay a high financial and sometimes a high emotional price because of breaches in biosecurity on the farm. Some diseases, even though they are not regulated, may require depopulation to rid the farm of the disease. Adhering to the principles of biosecurity does not guarantee your farm will remain disease free but it certainly stacks the deck in your favor.

I do want to briefly go over a few of the principles of biosecurity you should consider that may be helpful when developing your plan. First, limit new additions to the herd or flock. Ideally a closed herd or flock is best. That means if you are not bringing "all in" at the same time, you do not have a closed herd or flock. Obviously, this increases the chances of bringing a new disease into a susceptible group of animals. Therefore, there are two practices very important in minimizing disease risk when new animals are brought in. First, buy from reputable suppliers – those who are aware of and practice good biosecurity themselves. The second practice is quarantine of new additions for some period of time. Usually two weeks is adequate. This is especially important when you are not purchasing from sources whose history you know.

The second principle is to limit access to production areas by visitors. Many of the diseases that concern us are capable of simply hitching a ride on a person’s clothes, shoes, tires or other parts of the vehicle. I know many farms are literally show places the owners are proud of and are happy to take people on the 25 cent tour. While I am not saying to not ever let visitors on the farm, I am saying to be cautious. Take precautions like using foot baths. Keep a visitor’s log so you know who has been on the farm and when. Just be aware that someone could be on a farm in Africa two days ago and on yours tomorrow. Some viruses and bacteria can live on the soles of shoes that long.

A third principle of biosecurity is to limit contact with wildlife completely, or at least as much as possible. It is a fact that wildlife can carry diseases that may not make them sick but can cause huge problems in poultry and livestock. Recently a backyard chicken farm with about 100 birds had a diagnosis of highly pathogenic avian influenza or "bird flu" confirmed by USDA. Highly pathogenic avian influenza is a potentially DEVASTATING disease for the poultry industry. Anyway, the farm had a pond and small marsh frequented by wild ducks and geese. This case of high path AI was diagnosed as a result of heightened awareness of the disease after some wild water fowl in Washington State tested positive to the same strain of avian influenza.

Feed and water contamination is another place diseases may be introduced. It is important that feed is stored in a clean container not accessible to rodents or other vermin. Disease can be spread by opossums, raccoons, rats and even domestic cats that get into livestock or poultry feed. Water, especially sources that become stagnant, can be a good source of germ harborage.

Biosecurity is everyone’s responsibility. It is always easier to make sure the barn door is closed than to try to round up the animals after they have gotten out. I believe it is important for me to remind all of us, including myself, to not let our guards down. Animal agriculture has been a good place to be over the past few years. The folks who study the numbers for a living say that, barring a few outlying catastrophes, things should be good for a while. A disease outbreak could be one of those outliers. Don’t let a lapse in biosecurity cost you and the industry a big loss.

Dr. Tony Frazier is the State Veterinarian for Alabama. You can contact him at 334-240-7253.