(Longview, WA)  --  PeaceHealth St. John Medical Center in Longview is warning 260 patients of possible exposure to HIV and Hepatitis B and C.  Officials say the patients, who were fitted for sleep apnea devices, might have been exposed to the viruses.  "The Oregonian" reports the hospital discovered gaps in its sterilization documentation in late February, and staffers might not have followed all proper cleaning procedures.  PeaceHealth St. John says ten of those patients have been tested so far, and all results were negative.