More than 6,400 units of blood for transfusions shipped during the past 13 months could have been contaminated with hepatitis or other viruses -- and most may have already been used, according to the Japanese Red Cross Society.
The society said Tuesday that it managed to recall only 13 of the 6,419 units in question, meaning the remainder have likely been used, it said in a report submitted to the health ministry.
"The likelihood of a person infected (with a contagious disease) donating blood and the virus not being detected in the highly advanced screening tests is very low, " society officials said. "The number of blood units that might have actually been contaminated with a virus is very low."