Dr. Michael Libman, Director of the Division of Infectious Diseases at the McGill University Health Center (MUHC) carried out the study to find the most effective method to control the infection caused by this bacteria, and found that cleaning hands with soap and warm water was the best way.
To determine the best method to control Clostridium.difficile, Dr. Libman's team, which included Dr. Oughton, Dr. Vivian Loo, director of the MUHC Department of Microbiology, and Susan Fenn, MUHC assistant Chief Technologist, tested five separate hand washing protocols that emulated hospital conditions as closely as possible.
As a result of the conditions created, the hands of the ten volunteers were contaminated with C.difficile, which they washed successively with: regular soap and warm or cold water, antiseptic soap and warm water, an alcohol-based solution, and eventually with a disinfectant towel.
"The results were striking: the protocols that involved washing with water eliminated more than 98 percent of the bacteria, while washing with an alcohol-based solution eliminated almost none! The protocol involving a disinfectant towel eliminated around 95 percent of bacteria." Dr. Oughton said.
One feature of the bacteria family to which C.difficile belongs is the ability to produce spores when under stress. These spores, which are highly resistant, then produce new bacteria when favourable conditions return. Eliminating them is a major part of the challenge in controlling the bacteria.
"We think that alcohol eliminates the 'living' bacteria but not the spores, whereas the mechanical action of washing combined with the chemical action of soap eliminates both," Dr. Oughton said.
However, the alcohol "hand rubs" remains very effective and convenient for routine hand hygiene and eliminating non-spore producing bacteria. But, the study authors recommend using soap and water whenever contamination with C.difficile is suspected. Washing with soap and warm water also remains an excellent method to control nosocomial infections in general.
The results from this study were presented by Dr. Matthew Oughton, a researcher in Dr Libman's team, at the 47th Interscience Conference on Antimicrobial Agents and Chemotherapy in Chicago.