Chattanooga, Tenn. ? Viral infections, including hepatitis, have been found in 16 patients exposed to contaminated equipment at Veterans Affairs medical facilities, a department spokeswoman said Friday.

So far, 10 colonoscopy patients from the VA medical center in Murfreesboro, Tenn., have tested positive for hepatitis, VA spokeswoman Katie Roberts told The Associated Press. In a later e-mail, she reported six patients at the VA’s ear, nose and throat clinic in Augusta, Ga, tested positive for unspecified viral infections.

Roberts stressed that the source of the infections isn’t known, but said the VA will make sure those who tested positive “get the best possible treatment.”

“There’s no way to scientifically, conclusively prove they contracted this due to treatment at our facility,” Roberts said.

The number of reported infections could rise.

More than 10,000 veterans were warned to get blood tests because they could have been exposed to contamination at those two facilities plus a medical center in Miami.

All three sites failed to properly sterilize equipment between treatments, and the problems dated back for more than five years at the Murfreesboro and Miami hospitals.

Roberts said the department doesn’t yet have results from most of the veterans it warned.

A VA alert to patients said they “could have been exposed to body fluids from a previous patient.”

Roberts said four Tennessee patients have tested positive for hepatitis B and six have tested positive for hepatitis C, which is potentially life-threatening and can cause permanent liver damage. No one has tested positive for HIV, she said.

According to a VA e-mail, only about half of the Murfreesboro and Augusta patients notified by letter of a mistake that exposed them to “potentially infectious fluids” have requested department blood tests.

Some veterans said they decided to seek tests from their private physicians, rather than the VA.

The public first became aware of problems in February, when the agency announced it had sent letters to about 6,400 patients who had colonoscopies between April 23, 2003, and Dec. 1, 2008, at Murfreesboro and to about 1,800 patients treated over 11 months last year at Augusta.