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.

Vector-borne Pathogens-Testing Recommended Anaplasma spp. Cats with A. phagocytophilum infections can develop mild clinical illness that resolves quickly with administration of doxycycline. 79, 80 Research cats infested with field-caught I. scapularis from endemic areas become PCR positive before seroconversion, develop antibodies that can be detected by a commercially available assay used with dog sera, a and maintain rickettsemia for weeks before administration of doxycycline. 81 In addition, some cats with A. phagocytophilum infections will have morulae visualized cytologically in the cytoplasm of neutrophils. 79 Because this organism causes illness in cats, can be transmitted experimentally by blood inoculation, results in persistent infection, and is associated with illness, the panel recommends that optimally healthy cats from endemic areas be screened for A. phagocytophilum infection by serology and PCR and be negative in both tests (Table 2 ). However, in endemic areas, seropositive cats may be common, limiting the blood donor pool. Thus, the committee believes that if blood donor cats that are A. phagocytophilum seronegative and PCR negative are not available, cats that are A. phagocytophilum seropositive but PCR (or culture) negative could be used (Table 2 ). Because infection of cats with A. platys occasionally has been documented, cats living in areas endemic to Rhipicephalus spp. ticks should be screened with PCR (Table 2) .