Transfusion-transmitted malaria in the United States from 1963 through 1999.

BACKGROUND Transfusion-transmitted malaria is uncommon in the United States. After the report of three cases of complicated Plasmodium falciparum infection acquired by transfusion, we reviewed all cases of transfusion-transmitted malaria reported to the Centers for Disease Control and Prevention (CDC) from 1963 through 1999. METHODS Information on the patients was from surveillance reports sent to the CDC. Information about the implicated blood donors came from the National Malaria Surveillance System. To determine whether donors should have been excluded from donating blood, we compared their characteristics with the exclusion guidelines of the Food and Drug Administration and the American Association of Blood Banks. RESULTS Of 93 cases of transfusion-transmitted malaria reported in 28 states, 33 (35 percent) were due to P. falciparum, 25 (27 percent) were due to P. vivax, 25 (27 percent) were due to P. malariae, 5 (5 percent) were due to P. ovale, 3 (3 percent) were mixed infections, and 2 (2 percent) were due to unidentified species. Ten of the 93 patients (11 percent) died. There were potentially 91 donors (in two cases, two patients received blood from the same donor), 67 of whom (74 percent) could be identified as infective. Of 64 implicated donors whose country of origin was reported, 38 (59 percent) were foreign born. Among those for whom complete information was available, 37 of 60 donors (62 percent) would have been excluded from donating according to current guidelines (in place since 1994), and 30 of 48 donors (62 percent) should have been excluded under the guidelines in place at the time of donation. CONCLUSIONS Careful screening of donors according to the recommended exclusion guidelines remains the best way to prevent transfusion-transmitted malaria.