Fritsche, Thomas R.

Modified two-tiered testing (MTTT) algorithms for Lyme disease (LD), which involve the sequential use of orthogonal enzyme immunoassays (EIAs) without immunoblotting, are acceptable alternatives to standard two-tiered testing (STTT; EIA followed by immunoblots) provided the EIAs have been FDA-cleared for this intended use. We evaluated four Zeus Scientific LD EIAs used in two distinct MTTT algorithms for FDA review.

ABSTRACTBlood smear evaluation of two baboons (Papio cynocephalus) experiencing acute hemolytic crises following experimental stem cell transplantation revealed numerous intraerythrocytic organisms typical of the genusBabesia. Both animals had received whole-blood transfusions from two baboon donors, one of which was subsequently found to display rare trophozoites ofEntopolypoides macaci. An investigation was then undertaken to determine the prevalence of hematozoa in baboons held in our primate colony and to determine the relationship, if any, between the involved species. Analysis of thick and thin blood films from 65 healthy baboons (23 originating from our breeding facility, 26 originating from an out-of-state breeding facility, and 16 imported from Africa) for hematozoa revealed rareE. macaciparasites in 31%, with respective prevalences of 39, 35, and 12%. Phylogenetic analysis of nuclear small-subunit rRNA gene sequences amplified from peripheral blood of a baboon chronically infected withE. macacidemonstrated this parasite to be most closely related toBabesia microti(97.9% sequence similarity); sera from infected animals did not react in indirect fluorescent-antibody tests withBabesia microtiantigen, however, suggesting that they represent different species. These results support an emerging view that the genusEntopolypoidesMayer 1933 is synonymous with that of the genusBabesiaStarcovici 1893 and that the morphological variation noted among intracellular forms is a function of alteration in host immune status. The presence of an underrecognized, but highly enzootic,Babesiasp. in baboons may result in substantial, unanticipated impact on research programs. The similarity of this parasite to the known human pathogenB. microtimay also pose risks to humans undergoing xenotransplantation, mandating effective screening of donor animals.