HTLV in Sweden: antibodies to HTLV I antigens in experimental monkeys and their caretakers.

252 monkeys kept at 4 different Swedish universities and laboratories for experimentation were screened for antibodies to HTLV I associated antigens by means of a sensitive membrane antigen enzyme immunoassay (MA-ELISA). 17/185 Macaca fascicularis, 1/56 M. mulatta, 0/1 Cercopithecus aetiops and 0/10 Saimirii squiureus had antibodies. All of 11 MA-ELISA positive animals which were subjected to further testing were also positive in a competition assay for anti-HTLV p19 antibodies and in an anti-whole virion enzyme immunoassay. One colony of 32 M. fascicularis monkeys from the Philippines contained 7 antibody-positive animals. Except for one M. fascicularis which suffered from a chronic dermal lesion, major disease was not observed in any of the antibody-positive animals. None of 28 animal caretakers or experimenters, of which several had been repeatedly exposed to blood from antibody-positive animals, had antibodies measurable by the MA-ELISA. The contagiosity for humans of the majority of the antibody-positive monkeys thus appears to be relatively low. We conclude that the presence in Sweden of HTLV I antibody-positive animals probably does not constitute a great health risk. However, we consider it appropriate that antibody-positive animals should be handled with special care.