News & Events | Puget Sound Blood Center To Test for West Nile Virus

The highly sensitive test that detects genetic material of deadly West Nile virus is latest addition to Blood Center’s procedure to ensure safety of the local blood supply

JULY 7, 2003, SEATTLE — As warmer weather signals the re-emergence of mosquitoes, raising the possibility of the spread of West Nile virus to Western Washington, Puget Sound Blood Center announced that it will implement a West Nile screening test by mid-July. Last year, blood centers across the country learned that the virus could be passed through blood transfusions and organ transplants. This resulted in an unprecedented push by FDA, CDC, the pharmaceutical industry and blood centers to develop and assess a sensitive test to detect the virus. Though there have been no reported cases of West Nile virus in humans locally, authorities reported the virus was found in two birds and two horses last year.

How NAT Works
Puget Sound Blood Center performs laboratory tests to screen for infectious diseases in donated blood for the community blood centers in Hawaii, Alaska, and both Western and Eastern Washington. The test for West Nile, called a Nucleic Acid Test (NAT), is a sophisticated, highly sensitive experimental assay designed to detect the virus in blood. Created by Swiss pharmaceutical company, Roche, the test offers greater precision and accuracy in detecting viruses in blood by amplifying the presence of nucleic acid, the genetic material of viruses. The blood banking community is studying this test to protect the safety of the blood supply.

The Blood Center’s testing facility in Renton already uses the NAT to detect the presence of HIV, Hepatitis C and Hepatitis B in blood and Blood Center medical staff anticipate the addition of the West Nile virus test to ensure enhanced safety of whole blood and blood components, including fresh plasma, red cells and platelets. Though this particular test is new to all blood centers across the country, Blood Center executives expect that the test will ensure greater safety in the blood supply.

“Our past experience in using the NAT for other diseases shows that the test is an extremely robust and effective assay, detecting even small amounts of a virus in a blood sample,” said Dr. Mike Strong, executive vice president for the Blood Center. “This is significant for the safety of the blood supply, because we will be able to detect the presence of West Nile virus – even in potential donors who do not yet show symptoms for the virus. The combination of greater public awareness, the new test and the extensive questions we ask every donor should help to ensure as safe a blood supply as possible.”

In addition to implementing the investigational test, the Blood Center will continue to screen out donors who have symptoms of illness. Every donor completes a detailed health questionnaire and a physical examination, including a check of blood pressure, pulse, temperature and a test for red cell concentration (known as hematocrit). All donors must meet prescribed medical requirements before a unit of blood is collected.

Prior to the onset of mosquito season, Puget Sound Blood Center also has undertaken additional measures to safeguard the blood supply. The Blood Center built an inventory of frozen plasma donated prior to June. This blood component may be stored for up to one full year, although most will be transfused sooner.

Dr. Richard Counts, president of the Blood Center, emphasized that though the test is expected to provide improved safety of the blood collected, it, along with battery of 12 other tests the Blood Center applies to each unit of blood, will impact the blood supply.

“With the addition of the West Nile test, we anticipate some additional deferrals, further reducing the number of eligible donors in the community. In anticipation of this expected loss, we strongly encourage donors in our community to continue donating blood -- and for those who haven’t given blood to become first time donors. Your contribution may save a life.”

More information About West Nile Virus
According to a report filed by America’s Blood Centers, only about 20 percent of those infected by the virus show symptoms at all – which usually consists of mild flu-like symptoms, fever, headache and aches. However, certain patients are at increased risk of mortality: immunocompromised patients (people receiving organ or stem cell transplants, those with advanced malignant cancers or AIDS and persons on immunosuppressive medications), people over the age of 65 or women who are pregnant.

West Nile virus was initially recognized in the United States in 1999. In 2002, according to the Centers for Disease Control (CDC), the virus resulted in more than 4,100 West Nile virus infections and 284 deaths in 39 states and the District of Columbia.

About The Puget Sound Blood Center
Internationally recognized for groundbreaking research in transfusion and transplantation medicine, the nonprofit Puget Sound Blood Center is the resource for patients in Western Washington who need blood, tissue and specialized laboratory services. Founded in 1944, the Blood Center has a long and unique tradition of blending community volunteerism, medical science and research to improve patients’ lives. The Blood Center provides tissue and transplantation support to 185 hospitals across the Northwest and provides blood services to patients in more than 70 hospitals and clinics in 14 counties in Western Washington.