A majority of 46 Bristol County residents who contracted hepatitis A during a regional outbreak late last year were exposed to the virus at a Swansea D'Angelo shop, according to a final report by the Massachusetts Department of Public Health.
The report also determined that "improper food handling" was the likely cause of the outbreak and a D'Angelo manager was probably the "source."
The spread of hepatitis A in the region in November and early December affected a total of 52 people, including at least five who were hospitalized. It also forced hospitals to immunize more than 1,700 who were deemed at risk.
Throughout the crisis, health authorities publicized a running count of sick people who had eaten food from the D'Angelo franchise in the Swansea Place shopping plaza on Route 6.
But the state hasn't cited the shop as a site of exposure until now.
The report was compiled by three state epidemiologists who turned it over to health department officials on March 1.
The D'Angelo franchise informed the state on Oct. 25 that a manager had tested positive for hepatitis A, says the report, which does not identify the employee by name.
However, it says the manager was a Rhode Island resident who worked in two local D'Angelo shops, the one in Swansea and another in Seekonk.
The manager, a corporate trainer, told investigators that he was a diligent hand-washer who wore gloves when he occasionally prepared food. He had worked at both locations while he was infectious from Oct. 3 to Oct. 24, the report says.
"The risk of transmission to patrons was thought to be low since bare-hand contact with ready-to-eat foods was denied," the report says. "Thus, no public notice was released for patrons."
Hepatitis A is the mildest form of hepatitis infection. It is rarely fatal. Still, its symptoms -- fever, fatigue, loss of appetite, nausea and jaundice -- can be uncomfortable, and serious for people with weak immune systems.
Exposure to the virus is "fecal-oral," meaning that if people with hepatitis A fail to wash themselves properly after defecating, they can easily transmit the virus to others by touching food, or through close personal contact.
On Nov. 20, the Southcoast hospitals network reported seven hepatitis A cases to the state. Local health boards were notified and the state began its investigation.
Meanwhile, the caseload grew.
On Dec. 11, state epidemiologists initiated a case-control study, focusing their work on Bristol County residents who had symptoms between Oct. 18 and Nov. 29 and who tested positive before Dec. 11.
A total of 46 people fell within this group. Of these, 76 percent reported having eaten at the D'Angelo shop, the report says.
In early December, it was too late to immunize anyone who had been exposed at the D'Angelo shop in October and early November.
But health authorities were immunizing scores of people who ate certain foods from Rudy's Country Store on Wilbur Avenue in Swansea.
Two Rudy's employees had tested postive for the virus after eating at the D'Angelo shop. However, the state has not traced any hepatitis cases back to Rudy's, the report says.
Bill Chicarelli, a spokesman for D'Angelo, said yesterday that he was not aware of the state's report.
"I think what we're dealing with is still a level of speculation," he said. After listening to the report's summary, he said the language was not "definitive."
The Swansea D'Angelo shop has been closed for several months. Chicarelli said the closure is due to a scheduled remodeling of the facility and the shop should reopen in late April or early May.