Jan. 24, 2000 (Atlanta) -- For people seeking the best protection against disease-causing organisms in home kitchens and bathrooms, commercial disinfectants do a better job at eliminating them than do natural, environmentally friendly products. According to research in the North Carolina Statewide Program for Infection Control and Epidemiology (NC-SPICE), the commercial disinfectants tested killed 99.9% of bugs, including Salmonella, Escherichia coli(E. coli), and vancomycin-resistant Enterococci (VRE). The natural products eliminated only 90% of the bugs.
"We found the natural products were far less effective than commercial household disinfectants," lead researcher William A. Rutala, MD, tells WebMD. "To our knowledge, the activity of commercial household disinfectants against antibiotic-resistant microbes has not been reported previously." Rutala is a professor of medicine in the University of North Carolina (UNC) School of Medicine in Chapel Hill, director of NC-SPICE, and director of Hospital Epidemiology, Occupational Health and Safety Program at UNC Hospitals.
Rutala points out that more than 30 million food-borne infections have been estimated to occur each year, resulting in more than 9,000 deaths. The National Center for Infectious Diseases (NCID) estimates that 10,000-20,000 cases of infection from E. coli occur in the U.S. each year. Infection often leads to bloody diarrhea and occasionally to kidney failure. Most illness has been associated with eating undercooked, contaminated ground beef.
In this latest study, reported in the January issue of the Journal of Infection Control and Hospital Epidemiology, hospital disinfectants tested included TBQ, Vesphene, and ethanol. Household disinfectants tested were Clorox, ethanol, Mr. Clean Ultra, Lysol Disinfectant Spray, and Lysol Antibacterial Kitchen Cleaner. Vinegar and baking soda were the natural products tested.
The investigators tested the products against a variety of bacteria, representing medically important pathogens likely to contaminate the surface environment in the home: Staphylococcus aureus, Enterococcus, Salmonella, E. coli, and Pseudomonas aeruginosa. This study also tested the activity of household disinfectants against antibiotic-resistant microbes such as VRE, and methicillin-resistant Staphylococcus aureus (MRSA), a bacteria commonly found on the skin.
The researchers tested the effect of the disinfectants after 30-second and after five-minute exposures, then cultured the microbes to see how many remained. All of the hospital and household disinfectants were highly effective against the tested bacteria. The natural products, vinegar and baking soda, were less effective than the hospital and household cleaners.
Researchers also tested the effectiveness of the cleaners against poliovirus, since it is a very hard virus to kill. Clorox and Lysol disinfectant sprays performed the best against the poliovirus. Although 90% may seem to be a good enough tradeoff vs. the environmental risks of the more toxic products, Rutala says it is not a number that is deemed effective in killing bacteria and viruses: "For products that have claims of antimicrobial activity, it must have a 99.9% reduction."
The NCID recommends disinfecting areas where there are both high concentrations of dangerous germs and a possibility that they will be spread to others. That is because disinfectants, including solutions of household bleach, have ingredients that destroy bacteria and other germs.
According to the NCID, cleaning and disinfecting are not the same thing. In most cases, cleaning with soap and water is adequate. It removes dirt and most of the germs. However, in other situations, disinfecting provides an extra margin of safety. Given the right conditions, some germs can live on surfaces for hours or even days.
NCID points out that the kitchen is one of the most dangerous places in the house because of the infectious bacteria that are sometimes found in raw foods such as chicken. Also, there is a potential for germs to be spread to other people because that is where food is prepared. Another potential hot zone is the bathroom. Routine cleaning and disinfecting the bathroom reduce odors and may help prevent the spread of germs when someone in the house has a diarrheal illness.
According to Great Britain's Public Health Laboratory Service (PHLS), at this time it is not clear exactly what links there are between resistance to antibiotics and resistance to other antimicrobial products such as disinfectants. Antimicrobial products use a range of different chemicals to kill bacteria, and it is known that, occasionally, some bacteria can develop resistance to some of these chemicals; this may be linked to antibiotic resistance.
"Disinfectant resistance is nowhere near as common as antibiotic resistance, despite widespread, repeated use of disinfectants in many situations," says Rutala. "There are concerns about such a relationship, but it certainly is not established as it is with antibiotics."
Rutala says that now that the effectiveness of commercial disinfectants for use in the home has been demonstrated, a controlled trial should be undertaken to determine if routine disinfection of home environmental surfaces will lead to decreased infection rates among household members.
According to the PHLS, the use of antimicrobial substances cannot and should not be a substitute for good basic hygiene. "Adherence to basic hygiene rules is likely to be just as effective in providing a hygienic environment as using antimicrobial products," a PHLS representative said in a prepared statement. These basic rules include:
- Avoiding cross-contamination of raw and cooked foods.
- The regular cleaning of work-surfaces and kitchen utensils with warm soapy water.
- Good personal hygiene (particularly handwashing) by those handling food.
In the U.S., the Partnership for Food Safety Education -- a public-private partnership of industry, government, and consumer groups -- stresses four critical food safety principles:
- Clean: Wash hands and surfaces often.
- Separate: Don't cross-contaminate.
- Cook: Cook to proper temperatures.
- Chill: Refrigerate promptly.
Always wash hands with hot, soapy water:
- Before handling food.
- After handling food.
- After using the bathroom.
- After changing a diaper.
- After tending to a sick person.
- After blowing nose, coughing, or sneezing.
- After handling pets.
If hands have any kind of skin abrasion or infection, always use clean, disposable gloves. Wash hands (gloved or not) with hot, soapy water.