Serologic evidence for exposure to simian virus 40 in North American zoo workers

Some laboratories have detected DNA from the macaque polyomavirus simian virus 40 (SV40) in human tumors, but possible routes of infection remain unknown. In the present study, an enzyme immunoassay using viruslike particles (VLPs) was used to test 254 zoo workers for antibodies to SV40; 25 zoo workers with direct contact with nonhuman primates and 15 other zoo workers (23% vs. 10%, respectively; P=.01) were seropositive for SV40. Additionally, SV40 seroreactivity confirmed by competitive-inhibition experiments (i.e., blocked by addition of SV40 VLPs but not by VLPs for BK virus or JC virus, which are related human polyomaviruses) was increased in zoo workers with direct contact with nonhuman primates (10% vs. 3%, respectively; P=.04). SV40 seroreactivity therefore may reflect zoonotic exposure.