Transmission of toxoplasmosis in two renal allograft recipients receiving an organ from the same donor.

Toxoplasma gondii is a ubiquitous protozoan parasite. After acute infection it continues to exist as cysts in the muscles and brain. Recipients of organ allografts are susceptible to the disease as a result of reactivation of quiescent infection either by transmission from the organ donor or by consumption of undercooked meat. We describe 2 cases of fatal toxoplasmosis in renal allograft recipients who received their organs from the same cadaveric donor. Both recipients died 5 weeks after renal transplantation, within days of each other. Multiorgan involvement with toxoplasmosis was demonstrated at autopsy. No evidence of the parasite was found in the transplanted kidney, either at the time of insertion or at autopsy. Neither recipient had serologic evidence of previous exposure to T. gondii. The donor had positive IgG but indeterminate IgM antibodies suggesting acute infection at the time of death; there was no clinical suspicion that the donor died from acute toxoplasmosis. We conclude that toxoplasmosis was transmitted by the donor kidneys. In an attempt to minimize the possibility of future transmission, donors are now tested for anti-toxoplasma IgM antibodies and recipients are treated with trimethoprim/sulfamethoxazole for the first 6 months after renal transplantation.