The findings, published in the journal BMC Infectious Diseases, also show that spores from the bacteria Clostridium difficile linger in the bathroom even when it has been thoroughly wiped down.

Michelle Alfa of the Canadian Centre for Agri-food Research In Health and Medicine and a team of scientists from Manitoba investigated the spread of superbugs in hospitals such as methicillin resistant Staphylococcus aureus, or MRSA and C. difficile.

Alfa's toilet inspectors smeared UV lotion under the seats of 20 toilets and commodes used by seven patients with C. difficile infection, an additional 13 patients didn't suffer the infection.

The study found the commodes for the seven patients with C. difficle hadn't been properly cleaned 72 percent of the time and half of the toilets showed no residual UV lotion after cleaning.

The 13 patients without C. difficile had much cleaner toilets --14 percent showed the bacteria.