A Missouri Veterans Administration hospital may have exposed more than 1,800 veterans to life-threatening diseases such as hepatitis and HIV. Rep. Russ Carnahan John said Cochran VA Medical Center in St. Louis recently mailed letters to 1,812 veterans telling them they could contract hepatitis B, hepatitis C and HIV after visiting the medical center for dental work. Carnahan said he is calling for an investigation into the matter and has sent a letter to President Barack Obama about the issue. Dr. Gina Michael, the association chief of staff at the hospital, said the issue stems from a failure to clean dental instruments properly. She said some dental technicians broke protocol by hand washing tools before putting them in cleaning machines when the instruments were supposed to only be put in the cleaning machines. The hand washing started in February 2009 and continued to March of this year. The hospital has set up a special clinic and education centers to help patients who may have been infected, but Carnahan said he feels more should be done and those responsible should be disciplined.