House lawmakers have started calling for an investigation into reports that more than 1,800 veterans from Missouri, Illinois and other states may have been exposed to HIV or other diseases while getting dental treatment at a VA medical center in St. Louis.

Rep. Russ Carnahan, who represents St. Louis, on Wednesday asked the White House, the Veterans Administration and the House Committee on Veterans Affairs to look into the possibility that potentially deadly viruses were transmitted through equipment used at the John Cochran Division of the St. Louis Veterans Affairs Medical Center from February 2009 to March 2010.

According to a statement from the VA, dental equipment at the hospital in St. Louis was sterilized -- but it was "not sterilized to the exact specifications of the manufacturers guidelines."

"This is absolutely unacceptable," said Carnahan, a Democrat. "No veteran who has served and risked their life for this great nation should have to worry about their personal safety when receiving much needed health care services from a Veterans Administration hospital."

Rep. Sam Johnson, R-Texas, a veteran of the Korean and Vietnam wars, called the medical errors "unacceptable, offensive and objectionable."

"As a nation we vow to protect those who protect us," he said, calling for a "full congressional investigation to get to the bottom of this."

Although the VA concluded that the risk of “infection was extremely low," the agency decided it was still necessary to disclose the error in a letter sent Tuesday to 1,812 patients who were treated at the medical center during the 13-month period. They are now offering free blood tests to screen for HIV as well as Hepatitis B and C.

"VA leadership recognizes the seriousness of this situation and has implemented safeguards to prevent a similar situation from occurring again," the letter reads.

The VA issued a statement Wednesday that said dental clinic at the hospital was shut down while an inspection was done and a newly renovated space already under construction during the period under question opened up in May. The St. Louis Veterans Affairs Medical Center provides health care to more than 50,000 veterans a year.

But Carnahan said those responsible for the errors should be disciplined. 

"I can only imagine the horror and anger our veterans must be feeling after receiving this
letter," said Russ Carnahan. "They have every right to be angry. So am I."

This is not the first time a VA hospital has come under fire for medical negligence.

In November 2009, serious safety issues continued to plague a southern Illinois Veterans Affairs hospital even after major surgeries were suspended because of a spike in patient deaths.

According to a federal report, surgeons at the VA medical center in Marion, Ill., performed procedures without proper authorization, patient deaths were not assessed adequately and miscommunication between staff members persisted.

The hospital had been under intense scrutiny since 2007 when a former surgeon resigned three days after a patient bled to death following gall bladder surgery. All inpatient surgeries were suspended within a month.

In August 2009, it was uncovered that six more cancer patients were being given incorrect radiation doses at the Veterans Affairs Medical Center in Philadelphia, bringing the total to 98 veterans who were given the wrong treatment over a six-year period.

The errors happened in a common surgical procedure used to treat prostate cancer.

And earlier in 2009, the VA warned more than 10,000 veterans to get blood tests because they could have been exposed to contamination while getting colonoscopies in Murfreesboro, Tenn., and Miami.

"You'd think the VA folks would have learned their lesson after the Walter Reed fiasco," Johnson said. 

The Associated Press contributed to this report.