An undergraduate student at the University of Wisconsin conducted a study to determine where pathogenic microorganisms may be hiding in schools.
According to the student, Zhicong Wang, the whole premise for his study was that “pathogenic microorganisms are serious concerns in schools… [and] can cause disease in humans. Therefore, schools must monitor microorganism counts to prevent serious outbreaks.”
To conduct his study, he swabbed the usual “suspect surfaces” where pathogens have been found in schools before such as bathroom doors and sinks. However, he added one more surface that is rarely checked: 15 hall passes that students, parents, and other visitors are asked to carry while in the school.
As to the actual testing procedure for the 15 hall passes, Wang reported he did the following:
• Removed new sterile swabs from wrappers, unwrapped new water containers, and filled them with sterile water
• Moved the swabs horizontally and vertically over the hall passes, allowing for the highest amount of contact
• Placed the swabs in the water containers for up to 24 hours.
• The samples were then spread evenly over Petrifilm in Petri’s plates
• The plates were then incubated for two days at 95 degrees (F) and four days at 77 degrees (F); a total of six days
After conducting the tests, Wang reported there were significant amounts of Staphylococcus aureus and other bacteria on the hall passes. Including the sinks and doors, more than 18,000 Colony Forming Units (CFU) of bacteria were found, many potentially health threatening.
However, “as revealing as this study is, my concern is that it took so many steps and six days to get the results,” says Brad Evans, CEO of OptiSolve, a surface assessment tool that helps uncover hidden pathogens on surfaces in minutes. “During those six days, scores of students could become ill. Fortunately, newer technologies [have] ended the need for this old-type testing procedure.”
Source: Potential Pathogens in the School Environment, Zhicong Wang Undergraduate, Biology, University of Wisconsin 2007