Disinfectant Facts And Fallacies
While it seems straightforward, disinfection is pretty easy to screw up. It's not uncommon for me to find illogical or completely ineffective "disinfection" practices when I do farm investigations. In general, people don't really understand much about disinfectants and disinfection. That's not too surprising because it's not exactly a common or enthralling topic (and I didn't really know much about it until I became focused on infection control).
Good routine cleaning and disinfection practices are important for all barns, but the specific needs vary greatly between facilities. Proper disinfection practices are particularly important in certain situations, such as in foaling stalls, stalls housing sick horses and isolation areas. Because problems are so common, everyone should think about their disinfection program and the disinfectant(s) they use. When in comes to the disinfectant, here are some questions everyone should ask themselves:
Is it actually a disinfectant?
- Some people mistakenly use cleaners as disinfectants. Cleaners help remove debris and make the surface look good (i.e. clean), while disinfectants kill microorganisms through their chemical activity. You need a clean site for disinfectants to work, but using a cleaner in place of a disinfectant won't get rid of the microorganisms that remain after the visible dirt has been removed.
What kind of disinfectant is it?
- Disinfectants are a little like antibiotics. They have a "spectrum of activity" which tells you what types of microorganisms that they kill. Some disinfectants kill a wide range of microorganisms while the activity of others is more limited. Some work well in the presence of some dirt and debris, while others are readily inactivated and essentially won't work at all unless the surface is very clean first. Some are quite toxic and some are pretty innocuous.
What concentration should be used?
- There should be specific instructions on the product. Some are "ready-to-use" and don't need dilution. Most come as concentrates that need to be properly diluted. Excessive dilution will reduce the chance of of the disinfectant working. Inadequately diluting the concentrate ends up costing a lot more because you waste the product, and high concentrations of some disinfectants can be harmful. "Add two splashes to a bucket" is not proper dilution. You need to measure.
What contact time is needed?
- Disinfectants don't work instantly. They need time. Usually, it's anywhere from five to thirty minutes, depending on the disinfectant.
Common disinfection errors or misconceptions
A nice smell means it's clean.
- Clean actually has no smell at all. Products that leave a residual smell do so for aesthetic purposes, not for any real effect.
All disinfectants are created alike.
- Disinfectants are quite variable, in terms of the different organisms they can kill, how well they work in the presence of dirt and debris, how quickly they work, how toxic they are, and other factors.
The label says it kills 99.99% of microorganisms so it must be great.
- This type of advertising is misleading. Killing 99.99% of selected organisms in a lab environment is different than killing the entire range of possible microorganisms encountered in a barn, and in the presence of debris and difficult-to-disinfect surfaces.
If the area is dirty, just use more disinfectant
- Cleaning removes 80-95% of microorganisms, and is the most important step of the disinfection process. If the area isn't cleaned properly and has a lot of dirt and debris, the disinfectant will not be very effective, regardless of how much is used. There's no substitute for good old fashioned "elbow grease" when it comes to getting a barn clean.
One disinfectant is good, so two must be better
- A single disinfectant with a good disinfection protocol is adequate. There should be no need for multiple products, unless you want to have a higher level disinfectant available for certain situations (e.g. a stall for a horse with diarrhea). However, you should never mix disinfectants, because highly toxic by-products can be produced.
I'm not having any infectious disease problems, so I don't need to worry about my disinfection practices.
- Everyone that has an outbreak can say, right before the outbreak, that they had no infectious disease problems. Just because things are going well today doesn't mean that things will be fine tomorrow. It's a common perception, however, and often we don't find out about peoples' inadequate disinfection (or other infection control) practices until we are dealing with an outbreak. There's no guarantee that a better disinfection program would have prevented the outbreak, but it certainly wouldn't have hurt and may have helped reduce the problem. It's much easier to review things and make improvements before there are problems.
What a great article on a topic that is so often overlooked. It is so important to keep your horse stalls clean and free of bacteria as much as possible. This should start with designing the stall using materials that will not promote or harbour bacteria and trying to minimize the use of bedding where possible.
When it comes to cleaning as your article does such a good job of explaining, a simple "hose out" of the stall will not suffice, nor will a dash of disinfectant. Use the correct amount of disinfectant and use the right disinfectant.
It's amazing how often cleaning is mistaken for disinfecting. Great job explaining the difference. Proper disinfection really can save a lot of time, money and most important suffering. One thing people should consider is the toxicity of the disinfectant their using and how it may effect people and animals in the areas it is used. Many disinfectants leave toxic residue that can be transferred into food, water, and even through the skin or air.