Healthful Cleaning
Jun 1, 2009 12:00 PM, By Charles P. Gerba
The importance of infection control in education institutions.
Disease control
Proper hygiene and cleaning are effective mechanisms in controlling the spread of infections caused by norovirus and MRSA. The CDC lists five factors that make it easier for MRSA to spread in schools, which they refer to as the five Cs:
Crowding.
Frequent skin-to-skin contact.
Compromised skin (cut and abrasions).
Contaminated items and surfaces.
Improper cleaning.
The agency emphasizes that to protect people from being exposed to MRSA, it is important to maintain a clean environment. Establish cleaning procedures for frequently touched surfaces that come into direct contact with people's skin. Sanitize surfaces with detergent-based cleaners and disinfectants to remove MRSA from the environment. Encourage frequent handwashing and the use of alcohol hand sanitizers.
Germy classrooms
So how germy are classrooms? A group at the University of Arizona has done a number of studies to answer that question. Although only a few types of bacteria cause illness, knowing where bacteria are in a classroom reveals where the greatest risk of exposure to potential disease causing microbes can occur. This is a reflection of how often areas are touched and cleaned. School teachers have more bacteria on their desks and work areas than any other professions that were studied (doctors, lawyers, accounts, news reporters, bankers) — more than 20 times anyone else. This probably is because of their repeated contact with children, who experience more infections than adults, and the amount of material that crosses their desks every day. In the study, bacteria were found in the greatest numbers on the following surfaces:
- Water-fountain toggle.
- Pencil sharpener.
- Computer keyboard.
- Faucet sink handle.
- Student desktop.
- Classroom entrance doorknob.
In these same classrooms, the influenza virus and the norovirus are found on student desktops most often, followed by sink faucet handles and entrance doorknobs. Influenza virus was detected on up to 50 percent and norovirus up to 22 percent of the surfaces throughout the day during the winter, when these viruses are common.
Can good hygiene and cleaning practices reduce illness in school children? There's no easy answer. Children may acquire infections at home or from playing with other children, or other activities outside school. This makes it difficult to prove the impact of proper cleaning and disinfection. However, in several studies, handwashing and the use of hand sanitizers have been shown to reduce illness and absenteeism rates among both children and adults by 30 to 50 percent.
To show the impact of proper cleaning and disinfecting, a study called for cleaning and disinfecting the classroom desks of first-, fourth- and fifth-graders after the end of each school day. Absenteeism was reduced by 50 percent compared with classrooms where this was not done. In another study, the impact of providing an alcohol-based sanitizer and disinfecting key surfaces in the classroom resulted in a reduction by more than 50 percent in the occurrence of noroviruses on surfaces. Thus, it was not surprising that student absenteeism because of diarrhea also was reduced (Sandora, T.J., M.C. Shih, and D.A. Goldmann. 2006. "Reducing absenteeism from gastrointestinal and respiratory illness in elementary school students: A randomized, controlled trail of an infection-control intervention." Pediatrics. 121:1555-1562).
However, it is important to emphasize the words "proper cleaning." Improper use of cleaning tools (mops, cloths) can result in additional contaminations of surfaces. After an outbreak of norovirus at a university, crews that were cleaning improperly increased the number of surfaces in residence hall rooms contaminated with norovirus. Thus, proper use of cleaning tools and use of disinfectants is essential in reducing the spread of disease-causing microbes.
Gerba is a microbiology professor at the University of Arizona and a spokesman for the Coverall Health-Based Cleaning System. He can be reached at gerba@ag.arizona.edu.
Notable
8 Number of colds that the average child catches each year.
Source: Centers for Disease Control
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