As the number of West Nile virus cases continues to rise, health officials say the outbreak poses little risk to the nation's blood supply. NancyKay Sullivan Wessman, a spokeswoman for the Mississippi Department of Health, said no blood donation regulations have been instituted because of West Nile.
"Transmission of West Nile through blood has not been reported, but theoretically that transmission could occur,'' Wessman said. "The risk is low.''
Richard Davey, the chief medical officer for the New York Blood Center, said when West Nile first appeared in New York in 1999, the Centers for Disease Control and Prevention calculated the risk to the blood supply. Because there are no records of anyone ever contracting the mosquito-borne West Nile virus through a blood transfusion, Davey said the model is hypothetical.
"For transmission to occur, the person would need to make a donation while the virus was still in the blood, and the virus isn't around more than a week after being bitten,'' he said. "Even with the worst case scenario... there's a possibility of two transmissions in every 10,000 donations.''
Davey said even if a transmission did occur, the risk to the recipient is unknown and probably mild. Two deaths in Mississippi and seven in Louisiana have been linked to West Nile. More than 160 people have been infected in nine states and the District of Columbia, including 85 in Louisiana and 48 in Mississippi. Mississippi Blood Services spokeswoman Dani Edmonson said donors in the state don't seem to be spooked by the prospect of West Nile infecting the blood supply.
"Please don't be concerned about the safety of the blood supply,'' she said. "We'll be the first to say there is a problem if there is one.''
Edmonson said one person who contracted West Nile earlier this summer came in to donate, which he was allowed to do because the risks appeared to be extremely low.
"The risk of not having a blood transfusion if you need it is far worse than the risk of getting West Nile,'' she said.