Reducing equine disease transmission - hand hygiene study

September 7, 2007

A pilot study carried out at Ontario Veterinary College and Colorado State University College of Veterinary Medicine, suggests that alcohol-based hand rubs may be at least as effective as hand washing with soap to reduce the spreading of infections between horses in equine hospital and clinics.

In recent years there has been an increase in reports of infection being spread; examples include methicillin-resistant Staphylococcus aureus (MRSA) and Salmonella spp.

Washing hands with soap and water between patients is good basic hygiene practice. But there are various reasons it might not be practiced as often as it could be. Regular washing may lead to drying and cracking of the skin. Especially outside the hospital environment soap and water may not be readily available.

The researchers found that alcohol-based hand rubs, with or without additional antibacterial agents, are rapidly effective against a wide range of organisms. They may have advantages over antibacterial soaps. For example, they may be easier and more convenient to use, and may cause less skin irritation. But are they as effective at reducing the number of bacteria on the skin?

Veterinary students from the two colleges carried out physical examinations on horses, under the supervision of Dr Josie Traub-Dargatz. The standardized examination procedure included inspecting the eyes and ears with a pen torch, running the hands all over the body, measuring the rectal temperature, inspecting the oral mucous membranes and picking up all the feet. Samples were collected for bacteriological culture before and after handling the horse (from the left hand) and before and after cleaning the hands (right hand).

Three hand-cleaning protocols were assessed:

Because of the wide variation in bacterial numbers the researchers reported the reduction in bacterial number on a logarithmic scale. They found that after washing the hands with antiseptic soap the bacterial count fell by less than 0.6 log10. In contrast, the bacterial count was reduced by between 1.29 log10 (CSU) and 1.44 log10 (OVC) for the alcohol-gel group, and 1.47 log10 (CSU) and 1.94 log10 (OVC) for the chlorhexidine-alcohol lotion group.

Both alcohol-based hand rubs produced significantly larger reductions in bacterial count compared with the hand washing. The chlorhexidine-containing alcohol rub appeared to be slightly more effective than the alcohol gel but the difference was not statistically significant.

The study showed that the alcohol-based products were effective at reducing the bacterial counts, even though they are not intended for use on grossly soiled hands. Dr Traub-Dargatz points out that this is an important finding for ambulatory practitioners who may not have ready access to hand-washing facilities. However there was no evaluation of the impact on viruses or on some specific bacteria that may pose a nosocomial risk such as Clostridium difficle.

 

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