There may not be mosquitoes in the winter, but the bugs that carry West Nile virus will be back again in the summer, experts warned.

Blood banks hope implement a screening test for the virus soon.

“The FDA is scrambling to have one by next summer,” said John Elliott, blood bank supervisor at Mary Greeley Medical Center. Elliott said there is currently no test on the market that blood banks can use to detect the virus in donated blood.

“There are some general suggestions that the West Nile virus can be transmitted by blood transfusions,” said Wayne Rowley, professor of entomology.

For now, Mary Greeley and other blood banks conduct a verbal screening process and a mini-physical to ensure a suitable donor.

“We run a screening test for Hepatitis B, Hepatitis C, HIV, antibodies, syphilis and other things, but not for West Nile,” Elliott said.

After giving blood, a donor is told to call in if they start feeling ill. Their symptoms are evaluated for anything that would indicate West Nile, Elliott said. The donated blood is subsequently discarded if it might have the virus.

According to the Centers for Disease Control and Prevention Web site, www.cdc.gov, about 20 percent of those infected display mild symptoms of West Nile, including fever, headache, body aches, and occasionally a skin rash and swollen lymph glands.

“No one in our donor population has had West Nile symptoms,” Elliott said.

Also cited on the CDC Web site, as of Nov. 21, there have been 3,701 human cases of the West Nile virus, with 212 human deaths nationwide.

This year in Iowa, 50 people were infected by the disease. Two of those people died, Rowley said.

He said the West Nile virus was first discovered in the United States in August 1999.

It is transmitted to humans by mosquito bites, and there is no evidence that humans can contract the disease from infected animals, Rowley said.