Trypanosoma cruzi survival following cold storage: possible implications for tissue banking.

While Trypanosoma cruzi, the etiologic agent of Chagas disease, is typically vector-borne, infection can also occur through solid organ transplantation or transfusion of contaminated blood products. The ability of infected human cells, tissues, and cellular and tissue-based products (HCT/Ps) to transmit T. cruzi is dependent upon T. cruzi surviving the processing and storage conditions to which HCT/Ps are subjected. In the studies reported here, T. cruzi trypomastigotes remained infective 24 hours after being spiked into blood and stored at room temperature (N = 20); in 2 of 13 parasite-infected cultures stored 28 days at 4°C; and in samples stored 365 days at -80°C without cryoprotectant (N = 28), despite decreased viability compared to cryopreserved parasites. Detection of viable parasites after multiple freeze/thaws depended upon the duration of frozen storage. The ability of T. cruzi to survive long periods of storage at +4 and -80°C suggests that T. cruzi-infected tissues stored under these conditions are potentially infectious.