A 72 percent increase in deaths linked to the hospital superbug Clostridium difficile was disclosed by the Office for National Statistics in England. It said the infection was mentioned on 6,480 death certificates in England and Wales in 2006, compared with 3,757 in 2005. The figures showed deaths linked to C difficile were nearly four times more than deaths involving MRSA, which fell slightly in 2006 after rising for 10 years.