Update on Canine and Feline Blood Donor Screening for Blood-Borne Pathogens

Wardrop, K.J.; Birkenheuer, A.; Blais, M.C.; Callan, M.B.; Kohn, B.; Lappin, M.R.; Sykes, J.

Direct comparisons among different tests for infectious disease agents are generally not available unless published. See the reference list of the main document. mentally, SC inoculation of E. canis results in dosedependent infection and positive blood cultures. 28 Screening of potential donor dogs for antibodies to some Ehrlichia antigens can be performed by IFA assay, 1 of several commercial point-of-care assays, a,c,d or other laboratory-based assays. b Variable serologic crossreactivity occurs among some Ehrlichia species. In 1 of the point-of-care assays, a recombinant peptide antigens of E. canis and E. ewingii are combined together in a single spot, so a positive result reflects either seroreactivity to E. canis, E. ewingii, or both pathogens. The sensitivity and specificity of this assay compared to IFA have been reported. 8 The clinical sensitivity and specificity of other available assays require further study. Because serological reactivity against E. canis, E. ewingii, and E. chaffeensis is variable and not known for all assays, and because infection can be documented by broadrange PCR assay before seroconversion, the panel believes the optimal standard is to use donors that are seronegative and PCR negative (Table 1 ). This is most important for E. canis because it is the most important primary pathogen.