Survival and infectivity of Trypanosoma brucei in refrigerated pig blood.

Trypanosoma brucei parasites survived for 72 h or longer in refrigerated pig blood. The survival period was directly proportional to the initial parasite concentration of the sample. Infectivity of the parasites declined faster than survival, being less than 1 per 10(5) motile organisms at 72 h. The stage of infection in the pig (early vs. late) did not appear to influence subsequent survival periods or infectivity of the parasites in vitro.