A number of studies have taken place in the United States; in 2005 an undercover investigation of New York gyms conducted by Dr. Philip Tierno, Adjunct Associate Professor of Microbiology at NYU Medical School, came back with some disturbing findings.
Dr. Tierno, who gained international recognition as the man who helped solve the mystery behind toxic shock syndrome, stated that the gym is an unusually effective place for the transmission of germs. "There are millions and millions of germs on human skin. So when anyone sweats, they come pouring off."
They found staphylococcus, streptococcus viridans, diptheroids and e-coli - the most common bacteria in human feces. But Tierno said the bacteria found inhuman feces, e-coli, was worst on the shower floor. "Germs do survive in the shower... on the walls and on the floor," he said. "I found them in hoards. Unbelievable quantity."
In October 2006 Darleen Franklin, the SF State microbiology Media Kitchen Supervisor, was commissioned to test what types of bacteria and fungi live in the San Francisco State Gym. Ms. Franklin swabbed the shower floor in the women's locker room, a barbell from the weight room, a bathroom door handle in the men's locker room and a workout mat. The shower floor in the women's locker room showed the most types of bacteria.
In 2001 an independent study conducted by the Stoutonia on a University of Wisconsin-Stout dormitory bathroom the toilet seat, the shower floor and the floor around the sink were all tested for the most bacteria growth.
The results showed that the floor possessed a multitude of different micro-organisms including whatever is tracked in on the bottom of bathroom-bound shoes. But the shower floor held even more bacteria because the moist surface feeds the bacteria that are washed from the people showering.
In April 2005, a paper published by the Department of Health and Human Services in the US under the heading "Emerging Infectious Diseases," detailed research carried out following an outbreak of community-associated MRSA that occurred in a college football team from August to September 2003.
The research showed a direct correlation between lack of hygiene in the communal facilities, especially where bars of soap were shared, and the spread of MRSA. Daily hexachlorophene showers were used from August 25 to September 19 and during the 4 weeks after they were discontinued, no new infections were reported. In the following month MRSA SSTI developed in 4 players.