Biosecurity efforts cost considerable resources, both human and financial, and must be predicated on economic considerations. However, when we consider the risk of zoonotic agents, those that can affect humans, economics may become a secondary factor.

In fact, it is estimated that 75% of all infectious diseases of humans come from animals. Most of these originate from wildlife like rabies, West Nile virus and Human Immunodeficiency Virus (HIV). But domestic livestock are not excluded. Pigs continue to harbor a few occasional zoonotic agents, but the industry has done a stellar job of reducing zoonotic risk.

Even so, E. coli, methicillin-resistant Staphylococcus aureus (MRSA), salmonella, yersinia, erysipelas, leptospirosis, hepatitis E and swine influenza virus, along with a few other infectious agents, remain as potentially important diseases that can infect people.

However, farm workers do not appear to be at a greater risk of developing disease from these agents than the general public.

Many of the critics of modern animal agriculture also consider antibiotic resistance as a form of zoonosis, potentially afflicting harm on humankind. The scope of antimicrobial resistance is too large to be considered in this general biosecurity discussion.

Seasonal influenza (human), salmonella and E. coli bacteria are a few of the agents that can transmit from humans to pigs.

Biosecurity should address both sides of the transmission issues.

Biosecurity Successes

The modern pig farm is typically operated all-in, all-out by room, by barn, and in large operations, by site. Biosecurity has become an important component of this production structure and greatly reduces disease risk or its expression.

This modern model is used by the vast majority of our industry, regardless of operation size. It reduces stress, movement and mixing, and allows more efficient and efficacious use of vaccines and antibiotics. It also reduces the risk of disease agents moving from pig-to-pig, pig-to-human and vice versa. The modern North American pig production system is a sustainable and efficient modus operandi, especially auspicious at reducing zoonosis potential by comparison to other pig industries around the world.

Those efforts have successfully eliminated or nearly eliminated lice, mange, roundworms, kidney worms, hook worms, degenerative atrophic rhinitis, pseudorabies, Classical Swine Fever (hog cholera), Actinobacillus pleuropneumonia (APP), eperythrozoonosis (Mycoplasma suis), trichinosis, tuberculosis, nodular worms, thorny-headed worms, swine pox, Transmissible gastroenteritis (TGE), vesicular stomatitis, swine brucellosis and a host of other disease agents from our swine industry. It was not so many years ago that these plagued pork production.

Only two of these agents were disposed of through government-sponsored-and-financed programs — hog cholera and pseudorabies. The others were eliminated or controlled by committed producers, high-health genetic suppliers, dedicated veterinarians and by modern all-in, all-out production methods.

Although antibiotics and vaccines have been useful, they alone didn't contribute to this massive shift in swine health. Concentrated animal feeding and breeding operations (CAFOs), which keep our pigs safe from disease while protecting the public health by avoiding zoonotic agent introductions, are the centerpiece of modern pig production, care and animal well-being.

This is the truth about CAFOs and the industrialized model. Even our smallest producers have adopted some or all of these practices. Although not perfect, our confinement operations provide the greatest efficiency, protection to the pigs and the farm workers; offer the greatest protection to public health; and are the most sustainable, efficient and disease-free operations in the global marketplace.

Biosecurity Procedures

Biosecurity procedures are designed to keep new diseases out; control those already present by limiting transmission and infection; and, if needed, contain any new disease agent, thereby preventing its spread to other farms or production segments.

Biosecurity can be divided into bioexclusion, biomanagement and biocontainment. Bioexclusion is often referred to as external biosecurity, bio-management as internal biosecurity.

Often, a new agent enters a segment of production (i.e. boar stud) but is transmitted to other sites because functional (effective) biosecurity methods are lacking. In this situation, functional monitoring is an essential component of biosecurity.

Internal biosecurity includes those methods that reduce the impact of disease agents already present in the operation. This is accomplished by reducing the dose of the agent, increasing herd immunity to the agent, controlling the timing of infection, and reducing environmental and biological stress. Both components of biosecurity will be discussed as they pertain to pig-to-pig, people-to-pig and pig-to-people risk factors.

There are numerous internal and external biosecurity procedures employed by the pig industry. Many are traditional and based on good common sense or extrapolated from human health or other industries. Over 20 years, much research emphasis has been applied to the swine industry, greatly improving our understanding of “functional biosecurity” — that which provides true cost-effective protection.

In all cases, the expected value created by exclusion and control over disease agents should be calculated and compared to the expected, continuous cost of the interventions. When global foreign animal diseases (FADs) are considered, almost any intervention of merit will meet this value criterion when considering the macroeconomic effect.

Next Page: Biosecurity Goals