FINAL GUIDANCE TO BLOOD INDUSTRY ON WEST NILE VIRUS
The Food and Drug Administration (FDA) issued guidance designed to protect the safety of the blood supply against West Nile Virus (WNV). This guidance for industry provides recommendations for assessing the suitability of potential donors and for the proper handling of blood products from donors known or suspected to have WNV infections.
The guidance applies to whole blood and blood components intended for transfusion and for use in further manufacturing. It is intended to reduce the risk of WNV through transfusions, particularly in geographical areas where human cases are occurring. FDA has issued the guidance for immediate implementation.
The guidance provides detailed information to help blood establishments decide which potential donors should be deferred; it also sets forth recommendations about the retrieval and quarantine of blood and blood products from donors who develop WNV illness or infection after donation or are suspected of having WNV infections.
In addition, the guidance describes circumstances in which blood collectors should consider notifying transfusion services of proven or likely WNV infection in a donor so that hospitals can trace recipients of blood components from the affected donor.
Finally, the guidance advises industry to encourage donors to report any illness suggestive of WNV (e.g. fever and flu-like symptoms) within 2 weeks of blood donation if WNV infection is circulating in the community.
The guidance builds on existing blood safety regulations that require blood establishments to defer donors who are not in good health. Since approximately 20 percent of persons with WNV have symptoms ranging from mild symptoms to fever and other flu-like symptoms, donor screening procedures already in place should identify these people. FDA reminded the blood industry of these existing provisions in an alert on August 17, 2002, which was updated October 2, 2002.
No additional screening questions are being recommended. Currently there is no practical method to distinguish between the vast majority of donors who may have received mosquito bites from uninfected mosquitoes from the small number who may be infected.
Because no screening tests are currently available for WNV, these recommendations for donor deferral and product retrieval are especially important. FDA is working with industry to facilitate the development and review of possible donor screening tests for WNV. FDA is organizing a scientific workshop on WNV testing on November 4 and 5 in Bethesda, MD.
Recommendations in the new guidance for donor deferral include deferring a potential donor with a medical diagnosis of WNV until 14 days after the condition is resolved an at least 28 days from the onset of symptoms or diagnosis, whichever is later. If a person is asymptomatic and did not have recent WNV symptoms, having a positive antibody test result alone would not be grounds for deferral.
For donors who report symptoms suggestive of WNV infection when cases are known to be occurring in the community, it is recommended the be deferred from donating for 28 days from the onset of illness or 14 days after the condition is resolved, whichever is the later date.
Recommendations are also given in the guidance to quarantine and retrieve any unused components if a donor later reports a medical diagnosis of WNV or if a blood donor is associated with a potential case of transmission to a transfusion recipient. FDA does not recommend these measures when donors report only mild cold symptoms without fever, or if donors only report receiving mosquito bites. In the case of plasma derivatives, such as Factor VIII, quarantine and retrieval are not recommended because the viral reduction processes have been shown to inactivate viruses similar to WNV.
FDA reminds potential donors that donating blood carries no risk of acquiring WNV. In situations where blood transfusion may be life-saving, the benefits of blood transfusion outweigh the risk of WNV infection. Bites from mosquitoes carrying WNV remain, by far, the most common means of transmission. The guidance can found on FDA’s website at
http://www.fda.gov/cber/gdlns/wnvguid.htm
Should people be afraid to receive a blood transfusion?
No. Many patients’ lives are saved by blood transfusions, and for most, the risk of not receiving blood is much higher than the risk of contracting a virus through donated blood.
If it is determined that these patients contracted West Nile through blood transfusions, is the blood supply “tainted” with the West Nile Virus?
No. The blood supply is made of individual donations from individual donors which are then transfused to individual patients. There is not one large vat of blood, as some people may envision. The national blood supply is not infected with West Nile. These are rare, isolated cases.
Why isn’t there a test for West Nile Virus that can be given to all potential blood donors?
West Nile is a new virus in the United States. It takes time to develop a test to detect viruses in blood. The national blood collection organizations, the FDA, and test manufacturers are working very hard to determine a practical way to screen the blood supply for West Nile. If a test is developed and recommended by FDA, blood centers will use it.
How will blood centers screen for West Nile before a test becomes available?
Blood centers will continue to screen donors as usual, by asking questions about their general health, taking their temperature, and deferring anyone who has flu like symptoms which are common for people infected with West Nile Virus. If a donor falls ill after their donation, they are always asked to alert the blood center and the blood is withdrawn from us.
Can’t people have West Nile Virus and not show any signs? What if they donate blood?
Yes, people can carry the virus and be asymptomatic. Blood centers always ask that donors contact blood centers if they develop fever or any other disease after a donation, and always withdraw these donations from their inventory. In case the blood has been shipped to a hospital, the hospital is notified, so physicians are prepared to deal with a potential problem and address it as soon as possible.
How long does West Nile Virus stay on the blood of an infected person?
After a person is bitten by a mosquito, the virus only circulates in the blood from 1-5 days. This is very different from HIV and HCV that stay in circulation for the rest of the person’s life.
Should people with mosquito bites be deferred from giving blood?
No. Especially during summer months, a majority of people have mosquito bites or have had on e in recent weeks. Deferring everyone who had recently been bitten by a mosquito could put the blood supply at greater risk – we would run the risk of not having enough donors and therefore not enough blood to meet patients’ lifesaving needs. In addition, as mentioned above, the virus only stays in the circulation for a few days.
Should blood centers stop accepting donations until a test is developed?
Absolutely not. One of the greatest health risks our country could face is a situation where we don’t have enough blood to treat patients. More than four million Americans need blood each year – without new collections, we could run out of blood and patient care would be at severe risk. A recent government study need found that 2 million Americans would die if the blood wasn’t there when it was urgently needed. What we need is for people to continue to donate blood if they are in good health. Case in point – the organ donor had received blood from more than 60 donors after being injured in a car accident. That is just one example of how much blood can be used to treat patients in need.
Can people contract West Nile Virus from donating blood?
No. Donating blood is 100% safe and donors are at no risk of catching a virus.
How often can people donate blood?
People can donate blood every 56 days, or every eight weeks – up to six times annually. Plasma can be given twice a week and platelets 24 times a year. Red blood cells have a 42-day shelf life and platelets only 5 days, so the supply must constantly be replaced. Only about eight million Americans donate blood – that’s less than three percent of the population.
Please contact Western Kentucky Regional Blood Center if you have any questions about donating blood. Thank you
Western Kentucky Regional Blood Center
3015 Old Hartford Road
Owensboro, KY 42303
270-684-9296