The Veterans Administration has told western New York members of Congress that more than 700 patients at the Buffalo VA Medical Center may have been exposed to HIV, hepatitis B or hepatitis C because of accidental reuse of insulin pens, according to a published report.

Authorities told The Buffalo News, which first published the report on its website Friday, there is a "very small risk" for the diabetic patients who may have been exposed to the reused insulin pens between Oct. 19, 2010 and November 2012.

The VA memo obtained by the News said the problem was discovered by a routine pharmacy inspection last Nov. 1.

The hospital "recently discovered that is some cases, insulin pens were not labeled for individual patients," Evangeline Conley, a spokeswoman for the hospital, told the newspaper. "Although the pen needles were always changed, an insulin pen may have been used on more than one patient."

Conley said that once this was discovered the hospital "immediately changed its procedures to prevent insulin pens from being reused.

Insulin pens used by diabetics to inject insulin can be disposable or reusable with replaceable needles and cartridges. But according to the Institute for Safe Medication Practices, even reusable pens should not be used on more than one patient.

After seeing the VA's memo, Rep. Chris Collins, a Republican who represents the Buffalo area, said he spoke with Dr. Robert A. Petzel, undersecretary for health at the Department of Veterans Affairs.

"His thought was that it's a very, very low chance of passing infection," Collins said. "But it's not out of the realm of possibility, and that's why they're testing everyone," Collins told the News.

Collins said that even with a fresh needle, contamination could have occurred if bodily fluid flowed back into the insulin pens.

The VA said it is offering free blood tests to rule out any infections.