American Red Cross officials say many donors have called in sick due to flu-like illness or they've called in right after they've donated saying they've come down with the flu.
Federal regulations require that person's blood needs be thrown out.
Dr. Ross Herron, medical director of the Red Cross, says it's highly unlikely anyone can catch the H1N1 virus or any flu from a transfusion, but he does get a lot of questions.
"I wouldn't worry about having a transfusion transmitted flu virus," said Dr. Herron. "It's something we haven't seen and don't expect to see much of."
Donors are thoroughly checked for fever and other signs of illness. The staff also screens potential donors very carefully about their health history.
To supply local hospitals, the Red Cross needs at least 1,200 donors a day. So far they've been fine.
But Dr. Herron says what's really helping keep the supply up is the downturn in the economy. People trying to save money are postponing elective surgeries, which reduces the need for blood.
"We're a little worried about what happens when the economy rebounds and people all of a sudden decide, 'I need to get medical care,'" said Dr. Herron. "What will happen to the blood supply then? Will we have enough to meet that rebound?"
All blood is screened for illnesses such as HIV and hepatitis. Ongoing studies confirm flu-like illnesses cannot be transmitted through blood, so Dr. Herron says people shouldn't be concerned.
"If you need a blood transfusion the blood supply is as safe as it's ever been," said Dr. Herron. "There are risks for everything, but if the benefits of the transfusion outweigh the risks then it would be time to have your transfusion."
Along with screening out those with obvious illnesses, blood bank workers are taking extra precautions when it comes to their environment. That includes extra hand washing and other infection prevention methods to make sure people realize it's safe to donate blood.