PRESENCE OF ANTIBODIES REACTING WITH PORCINE CIRCOVIRUS IN SERA OF HUMANS, MICE, AND CATTLE

Antibodies reacting with porcine circovirus (PCV) were found in sera o f humans, mice, and cattle by means of an indirect immunofluorescence assay (IFA) and an ELISA. In man, the highest seroprevalence (23.9 % i n IFA and 30.2 % in ELISA) was found among hospitalized patients with fever of partially unclear etiology. Non-hospitalized ''healthy'' pers ons of the former German Democratic Republic showed a significantly hi gher number of positive sera (IFA = 20%) than blood donors from Berlin -West (IFA = 8.6%). Murine sera reacted positive with PCV in IFA betwe en 12 to 69% in different breeding groups and about 35% of cattle sera were found reactive with PCV in IFA. Double-staining IFAs, immune-ele ctron microscopy and immunoblotting showed that non-porcine antibodies reacted with PCV structural antigen. Mathematical analysis releaved t hat in ELISA, non-porcine antibodies reacted specifically with PCV. Lo ss of binding specificity of non-porcine antibodies in ELISA after sto rage of sera and lower maximal optical densities obtained at equal tit ers in ELISA with non-porcine than with porcine sera suggest that anti bodies in man, mice and cattle are caused by related species specific viruses sharing antigenic epitopes with PCV.