Any farm or site that utilizes surface water is at risk for bird influenza virus introductions. Surface water can harbor many infectious agents that can infect pigs and humans, including avian influenza viruses. Water for pigs should be potable and free of bacteria and viruses. When surface water is the only available water supply, it should be monitored monthly with coliform counts and other tests that assure its safety and purity. On-farm water purification systems should be continuously monitored and maintained.

Internal Influenza Biosecurity

On rare occasions, swine influenza viruses infect humans. Although this seems to be on the increase, it may be a result of better surveillance and identification by human diagnostic labs. Influenza is now a reportable disease for humans; thus, all non-typeable isolates are identified in influenza-like illness situations.

Preventing influenza spread from pigs to people is not well established. It occurs so rarely that the circumstances leading to human infection are not well understood. Even so, washing hands frequently, especially before smoking, using smokeless tobacco products and before eating is important. It is especially important to safeguard individuals who are immune-compromised or suffering from other illnesses. Children may be at greater risk due to unrecognized hygiene, and past and present exposure factors. Although the overall risk of human infection with a swine influenza virus remains extremely remote, these precautions should be considered:

Use of dust masks and disposable gloves are of limited value in preventing infection from pigs-to-human and human-to-human, but may be of some value in preventing spread from humans to pigs. The use of disposable gloves will not prevent the spread of human influenzas to pigs since they become contaminated as quickly as the skin they cover. In farms where hand washing is limited, disposable gloves can provide a barrier if changed frequently, but offer little advantage to hand washing. Good quality double-strap dust masks may be of some value in protecting pigs if changed regularly and properly disposed of, out of reach from pig contact. It is thought that influenza is spread by larger respiratory droplets, which a dust mask will collect, reducing contamination of hands, clothing and farm environment.

Novel H1N1 vaccines for pigs will arrive on the market in late 2009 to early 2010. These vaccines should be highly effective since U.S. pigs have yet to be exposed. These killed vaccines should be focused on the growing pigs and avoided in breeding herds under most circumstances. Studies where the novel H1N1 is used in pig challenge, the lesions and clinical signs are similar to swine influenza, but are not considered mild. The pig H1N1 vaccine should reduce disease severity, virus shedding and clinical disease, but will not likely yield significant cross-protection against current swine influenza viruses.

In general, all-in, all-out movement of growing pigs, proper vaccination timing, hot water and detergent cleaning between groups are documented to reduce both viral and bacterial loads in the pigs' environment. It is important to recognize that disinfectants supplement the cleaning process and are not a primary means of sanitation within the farm. They are extremely important in transportation risk reduction, and most will destroy influenza viruses.