New Study Proves Virkon® S Misting's Superior Value

by 5m Editor
9 April 2008, at 11:37am

Us - A team of leading researchers in the USA have found that directed misting of a four per cent solution of disinfectant Virkon® S can successfully reduce environmental bacterial contamination, such as Staphs and Salmonella, to extremely low levels - significantly lower than many other disinfectant could achieve.

The misted dilution was successful in reducing environmental bacterial CFUs by > 99.9999% or the equivalent of a highly effective 6 logs1. Typically, a reduction factor or 3 to 5 logs is considered the minimum needed for effective disinfection, says manufacturer DuPont Animal Health Solutions.

Based on their earlier work2 with Virkon® S, Gage Patterson and Paul Morley of the Animal Population Health Institute and Colorado State University, USA performed a new field study to evaluate the efficacy of four per cent Virkon® S applied as a mist to surfaces in a large animal hospital. The purpose of the new study was to find a less labour intensive and disruptive means to disinfect the veterinary hospital's large animal facilities with extensive, unsealed electrical conduits and fixtures in the high ceilings of the buildings.

Various locations around the hospital were inoculated with Staphylococcus aureus and Salmonella enterica onto polyester transparencies. After misting with Virkon® S viable bacterial numbers were quantified and compared with growth from control transparencies to assess the reduction in bacterial count. The study showed that the mean reductions in recovery of Staphylococcus aureus and Salmonella enterica were significantly reduced by > 6 logs for both bacteria, an equivalent of a > 99.9999% reduction in CFUs.

On a Par and Better

When compared with other disinfectants, the authors stated that the efficacy of Virkon® S was similar to that achieved through aerosolisation of formaldehyde, but superior to that achieved by aerosolisation of a glutaraldehyde and quaternary ammonium compound mixture.

"From our experience with previous studies2, we selected a four per cent solution of Virkon® S as this has the greatest killing capacity,"explains Paul Morley.

"Our high, 20 foot surfaces and electrical work make cleaning and disinfection a challenge. We clean all the surfaces first, followed by a combination of foaming with disinfectant and then misting with Virkon® S to minimise environmental bacterial loads. Directed misting disinfection using Virkon® S enables us to get into all the difficult-to-access nooks and crannies," he adds.

In conclusion his team found that the directed misting application of four per cent Virkon® S proved to be a very rapid and efficient method of distributing disinfectant that could be easily applied to a variety of agricultural or veterinary settings. References
  1. Efficacy of directed misting application of a peroxygen disinfectant for environmental decontamination of a veterinary hospital. G Patterson, PS Morley, KD Blehm, DE Lee, M Dunowska. JAVMA, Vol 227, No 4, August 15, 2005
  2. Dunowska M, Morley PS, Hyatt DR. The effect of Virkon S fogging on survival of Salmonella enterica and Staphylococcus aureus on surfaces in a veterinary teaching hospital. Vet Microbiol 2005; 105:281-289.

5m Editor