Three US transplant patients have died after receiving organs from a donor who was exposed to a common rodent virus, probably from her pet hamster.

It was believed to be only the second documented case in which the viral infection LCMV was transmitted through an organ transplant.

The recipients of the infected donor's liver, lungs and one kidney died in April, a few weeks after the transplants, from lymphocytic choriomeningitis virus, which is associated with exposure to rodent waste, health officials said. Another patient who received a kidney from the organ donor is recovering.

The infection was traced to a female donor from Rhode Island, who died of unrelated causes. Officials said that a hamster kept as a pet in the woman’s home had tested positive for LCMV.

CDC investigators were testing the dead hamster to confirm the virus as the cause.

"We believe the hamster was the source, but we can’t rule out a common house mouse," said CDC spokesman Dave Daigle.

Two other people received corneas from the donor, in operations outside the United States. Officials from the federal Centers for Disease Control and Prevention said that they are investigating where those corneas went.

Health officials discovered the connection after a doctor at the Rhode Island hospital where one of the transplants was performed reported an unusual viral death. Investigators traced the death to the organ donor.

The virus LCMV is commonly found in house mice, but usually produces only flu-like symptoms in humans. It has also been associated with neurological illness and miscarriage in pregnant women.

In this case, the patients received large doses of medication that suppressed their immune systems, allowing the virus to grow, said state Health Department director David Gifford.

Donated organs are not routinely screened for rodent viruses, he said, and LCMV was not considered a threat to the organ supply.

"We would encourage people who are on the waiting list not to be concerned with this," Mr Gifford said. "This is an extremely rare and unusual event."

The Petsmart pet shop where the donor bought the hamster has stopped selling mice and hamsters, and given its import and sales records to the state Department of Environmental Management, he added. He refused to identify the victims or the donor, or to say how old they were.

Jennifer Pflugfelder, spokeswoman for Phoenix-based Petsmart, said the CDC took away about 60 hamsters, mice and rats last week, and the remaining animals were taken from the shop yesterday morning, she said.

Only one previous instance of LCMV causing a transplant-related death has been reported, in Wisconsin in December 2003, but it was not definitively linked to rodent exposure, said Dr. Matthew Kuehnert of the CDC.

Times Recommends

• Fish and chip shops ‘selling cobbler as cod’
• T in the Park festival at Kinross
• How to get Madonna’s Thighs