Some former cardiac cath patients at Houston Healthcare will receive certified letters this week in connection with a former medical technician charged elsewhere with spreading hepatitis C.

David Kwiatkowski, who worked in the cardiac cath lab at Houston Medical Center from October 2010 through March 2011, has been accused in Concord, N.H., of stealing anesthetic drugs and contaminating syringes that were later used on patients.

His strain of hepatitis C has been diagnosed on at least 30 Exeter Hospital patients. Hepatitis C is a blood-borne viral infection that can cause liver disease and other chronic health issues.

Some 12 hospitals across the country where Kwiatkowki worked as a contract technician are facing similar possibilities.

In a statement released late Tuesday, Houston Healthcare Chief Executive Officer Cary Martin said fewer than 100 patients will be receiving the certified letters.

"As we continue working with public health agencies in this ongoing investigation, future developments may lead to expanded testing recommendations," Martin noted in the statement. "We will provide updates as appropriate while working within applicable patient privacy and criminal investigation boundaries."

Martin did not give the exact number of local patients who would be receiving the letters nor did he reveal the contents and instructions the letters will contain.

In a statement released July 20, Martin said Kwiatkowski's service at Houston Medical Center had been confined to the cardiac cath lab and "he did not have access to the medication system."

An Associated Press story in late July said testing has been recommended for about 4,700 patients in New Hampshire. The 33-year-old technician also worked in Kansas, Maryland, Michigan, New York and Pennsylvania.

AP said 25 patients in Poughkeepsie, N.Y., have been asked to undergo testing. A hospital in Kansas is sending letters to 460 patients. Hundreds of patients at four hospitals in Maryland also are receiving letters, the AP noted.