Fatal West Nile Virus Infection After Probably Transfusion-Associated Transmission

Last week’s Morbidity and Mortality Weekly Report from the CDC included a case of fatal West Nile Virus transmission following a stem cell transplant to a man with non-Hodgkin’s lymphoma that took place in Colorado in August 2012. The patient was hospitalized for 4 weeks before illness onset, and received 6 units of red blood cells, 2 units of platelets, and 2 units of fresh frozen plasma.

The FDA guidelines require the screening of all blood donations for West Nile Virus in minipools of 6 or 16. The 10 associated donors were screened again following the patient’s diagnosis, with one donor being tested positive for WNV IgM anitbodies and WNV neutralizing antibodies by plaque reduction neutralization testing but the donor reported no history of illness before or after donation. The implicated donation was initially screened as part of a minipool of 6, which was initially found to be positive for West Nile Virus RNA. However, all the units composing the minipool were nonreactive when retested individually and were released per the FDA guidelines at the time.

This case may necessitate the FDA revisiting the guidelines for retesting and releasing units that test positive for West Nile Virus in minipool screenings to avoid any further transfusion-associated transmissions of West Nile Virus or other pathogens of interest. Read more….