Story highlights David Kwiatkowski also worked at Johns Hopkins in Maryland and in five other states

Kwiatkowski, 32, is accused of infecting at least 30 people

The evidence "points irrefutably to Kwiatkowski," a U.S. attorney says

Co-workers witnessed suspicious behavior and symptoms, according to an affidavit

A former medical technician was arrested Thursday in connection with a hepatitis C outbreak at a hospital in Exeter , New Hampshire, a federal prosecutor announced.

David Matthew Kwiatkowski, 32, is accused of infecting at least 30 people when he worked in the cardiac catheterization lab (CCL) at Exeter Hospital. He also is suspected of stealing controlled substance Fentanyl, a powerful anesthetic that is substantially more potent than morphine.

According to an affidavit filed in federal court in New Hampshire, Kwiatkowski is charged with obtaining controlled substances by fraud and tampering with a consumer product. He faces more than 20 years in prison if convicted.

"The evidence gathered to date points irrefutably to Kwiatkowski as the source of the hepatitis C outbreak at Exeter Hospital. With his arrest, we have eliminated the menace this 'serial infector' posed to public health and safety," said United States Attorney John P. Kacavas.

Multiple employees at the hospital said Kwiatkowski exhibited suspicious behavior, according to the federal affidavit.

He would leave the CCL during procedures, sweating profusely, and attended procedures on his off days, according to the affidavit.

On several occasions syringes were discovered in a restroom in the vicinity of the CCL, the affidavit said.

One witness even said that she thought Kwiatkowski "was on something" and unfit for patient care. Another co-worker said he remembered an incident when Kwiatkowski was red in the face and eyes and had white foam around his mouth while he was on duty.

Hepatitis C is passed through contact with contaminated blood, most often via shared needles, and is considered to be among the most serious of hepatitis viruses. It is typically asymptomatic, going undetected until liver damage shows up, according to the Mayo Clinic website

Prior to working in New Hampshire, Kwiatkowski was a traveling medical technician who worked on a contract basis in at least six other states. Gary Stephenson, a spokesman for Johns Hopkins Medicine, confirmed that Kwiatkowski worked at the hospital in Baltimore from July 2009 to January 2010.

Kwiatkowski, who is originally from Michigan and has hepatitis C, was arrested in an undisclosed Massachusetts hospital where he is being treated and will be held in custody once he is discharged.

It wasn't immediately clear whether he had legal representation.

Kwiatkowski told authorities that he found out he had hepatitis C in May 2012, but further investigation revealed he tested positive for the disease in June 2010.

A statement released by the hospital states that pre-employment drug testing and standard and criminal background checks were performed before he was hired.

"It is deeply disturbing that the alleged callous acts of one individual can have such an impact on so many innocent lives. As a result of his alleged actions, people in our community, who in many cases are the friends and neighbors of the 2,300 people who work here, now face the challenge of a potentially chronic disease," said Kevin Callahan, president and CEO of Exeter Hospital, in a released statement.