The good news is that influenza viruses are pretty wimpy. They’re enveloped viruses, meaning they are covered by a fragile fatty layer. This envelope is easy to disrupt, and doing so kills the virus. As a result, enveloped viruses don’t survive for long in the environment. In contrast, non-enveloped viruses can be very tough. Some survive for long periods of time in the environment and are resistant to certain disinfectants. Canine parvovirus, poliovirus and norovirus are some examples of hardy non-enveloped viruses.
But back to influenza. Because it’s enveloped, pretty much any routine disinfectant will inactivate it. The virus will also disintegrate on its own, given a bit of time. Survival for a day or two is possible on surfaces like stainless steel and plastic. Duration of survival is shorter on surfaces like cloth or paper, usually less than 8-12 hours (Bean et al, J Infect Dis 1982).
While it’s nice that flu virus doesn’t survive for long, in a veterinary clinic (or any other higher risk environment like a kennel) we’d rather speed up the process to reduce the risk of transmission. That’s where cleaning and disinfection come in.
- Cleaning is an important first step. Disinfection of grossly contaminated surfaces is difficult. Cleaning actually removes the majority of contaminants. So, skipping cleaning and going right to application of a disinfectant is not as effective and should be avoided.
- Basically any disinfectant will kill influenza virus. However, since we shouldn’t have tunnel vision about only targetting flu, it’s a good idea to use as effective a disinfectant as possible. (My main recommendation is an accelerated hydrogen peroxide product.) That being said, any routine clinic or kennel disinfectant is fine for the purposes of flu and many other bacteria and viruses.
- Disinfectants need to be used right. The proper concentration has to be used and the right contact time with the surface must be provided. These vary from product to product, so check the label. Contact time is often overlooked – a quick spray followed by an immediate wipe (as is common) may not do much beyond physical removal from wiping. The disinfectant needs to have time to do its job.
- Disinfectants only work where they have contact. Attention should be paid to fully covering potentially contaminated surfaces, as well as equipment such as stethoscopes, bowls and anything else that might touch a dog (particularly its mouth).
The approach to disinfection for influenza is pretty straightforward. The devil is in the details, though, as disinfection isn’t always done carefully or properly. It’s never a bad time to review disinfection practices to make sure they’re adequate, are understood by all personnel and are followed.