Health officials say a traveling medical technician accused of causing a hepatitis C outbreak in New Hampshire worked in at least six Michigan facilities from 2003 to 2007.
David Kwiatkowski is being held on federal drug charges in New Hampshire, and authorities are trying to determine whether he spread the virus elsewhere.
The Michigan Department of Community Health said Monday its "investigation has not uncovered evidence that the individual was infected with hepatitis C while employed at any Michigan facility."
The MDCH says a negative hepatitis C test result at one hospital allows the agency to exclude two hospitals from further examination.
The four remaining facilities are Sinai Grace Hospital in Detroit, Harper Hospital in Detroit, the University of Michigan Hospital in Ann Arbor and Oakwood Annapolis Hospital in Wayne.