DENVER -- A Colorado man who died of West Nile virus last year was likely infected through a blood transfusion, a report from the Centers for Disease Control and Prevention found.
The man, who was undergoing treatment for non-Hodgkin’s lymphoma at Presbyterian/St. Luke’s Medical Center, began developing West Nile symptoms after 29 days in the hospital, sharply narrowing the number of ways he could have been exposed to the virus, according to the CDC’s Morbidity and Mortality Weekly Report. He died after 47 days in the hospital.
Eighteen days prior to showing symptoms, the patient received a blood transfusion that health officials now believe contained West Nile.
Since 2003, blood donations have been routinely screened for West Nile virus, with 3,500 contaminated samples having been destroyed since then, the CDC reported. This appears to be the first case of West Nile infection in which a blood donation initially tested negative before going on to infect someone.
The FDA recommends that blood collection agencies use one methodology – “mini-pool” nucleic acid testing – when screening for West Nile, then switch to a more sensitive process – individual donation nucleic acid testing – during periods of high West Nile activity, the CDC report says.
It appears that in the Colorado case, the agency had no extraordinary reason to believe the sample might contain the virus, and so was using the less-sensitive method, according to the report.
The cancer patient’s weakened immune system likely was another factor that contributed to his infection, according to the report.
Most people infected with West Nile show no symptoms at all, so it's very difficult to screen infected donors before they give blood. The laboratories involved in screening the blood for the victim have since adopted a new policy to discard all blood samples that test positive for West Nile during pooled screening if a specific infected individual sample cannot be found, the CDC said.
The CDC did not name the patient. Presbyterian/St. Luke's released the following statement Thursday:
"Our infectious disease and blood bank teams worked diligently with the family, Tri-County Health Department, Bonfils (Blood Center), the CDC and the FDA to determine the source of the West Nile virus.
"Our investigation confirmed that Presbyterian/St. Luke’s Medical Center followed all appropriate blood donation protocols and testing procedures.
"Our hearts go out to the family and friends of this patient. We will continue to work with Bonfils, the CDC and the FDA in ongoing efforts to ensure the safety of all donated blood products, and to safeguard the well-being of the patients entrusted to our care."AlertMe