June 3, 2008— -- The antibacterial wipes that have emerged as a sanitary status symbol in homes, hospitals, schools, gyms and even grocery stores may not be the ultimate answer in hygiene — and they might even spread, rather than kill, bacteria.
Researchers from the Welsh School of Pharmacy at Cardiff University in Wales tested the cleaning power of three different types of antibacterial wipes containing either traditional disinfectants, detergents or natural antimicrobial substances, such as those extracted from plants.
A team led by microbiologist Gareth Williams used the wipes to clean surfaces that had been severely contaminated with the notorious bacterium Staphylococcus aureus — including the Methicillin-resistant type known as MRSA, which has become a growing concern in hospitals.
The study, presented Tuesday at the American Society for Microbiology General Meeting in Boston, found that natural antimicrobial wipes removed the most bacteria from surfaces, while disinfectant wipes did the best job of destroying bacteria.
"Ideally, you'd want the wipes to kill what they remove," Williams said.
But researchers found that all of the dirty wipes, including those with the disinfectant, still had some bacteria remaining on them. When they were reused, the wipes just transported the bacteria to another location.
"We would recommend that one wipe is applied in one application to one surface, and then discarded," Williams said. "This is in an attempt to prevent the transfer of bacteria to different surfaces."
The conditions in the study were meant to emulate the bacteria-filled environment of a hospital intensive care unit. Health professionals aim to control the levels of potentially dangerous bacteria in these settings through disinfection — in short, the removal of as many microscopic troublemakers as possible.
But disinfection should not be confused with sterilization. Disinfection is not designed to kill all organisms, but rather to simply reduce the number of organisms on a surface, said Donna Duberg, assistant professor of clinical laboratory science at Saint Louis University in St. Louis, Mo.
"Our bodies are designed to handle a certain number of bacteria," she said. Complete sterilization is unnecessary, especially in homes, which are much less contaminated than a hospital ICU.
"We use way too many antibacterial agents," Duberg said, adding that the overuse of products like wipes, soaps and cleansers that contain these substances can lead bacteria to become resistant to our methods of extermination.
"I personally believe there isn't anything that good, hot soapy water can't clean," she said.
Dr. William Schaffner, chair of the department of preventive medicine at Vanderbilt University School of Medicine, agreed that people should be careful to use antibacterial wipes appropriately to avoid spreading bacteria around their homes.
His motto for disinfectant wipes: "use it and lose it," especially on highly contaminated surfaces in the bathroom and kitchen. For example, don't use the same wipe to clean both the toilet and the sink. Schaffner called this type of reuse a "false economy," trading the price of wipes for the spread of germs.
But Schaffner added that in hospitals, surfaces are not the primary source of bacteria that infect patients. Other patients and health care workers are the ones who transmit the most germs. "It is hands that are the great transfer vehicle for bacteria from patient to patient," he said.
So the rising use of antibacterial wipes shouldn't overshadow the most important rule of hygiene: Wash your hands.