Potential human health risks associated with animal retroviruses: some hypotheses

Several studies have demonstrated the existence of morphological, biological, genetic and antigenic correlations between human and animal retroviruses. Furthermore, some agents of bovine and feline origin can also be considered useful comparative models for the pathogenetic study of human diseases such as leukaemia, acquired immunodeficiency syndrome (AIDS) and multiple sclerosis (MS). In spite of the existence of data suggesting a possible role of some animal retroviruses (e.g. the bovine leukosis virus, BLV) in the etiology and epidemiology of human leukaemia and MS, the true zoonotic potential of such agents remains unknown, but their genetic and antigenic linkages with some human lentiviruses (such as the human immunodeficiency virus-1, HIV 1) can make them hypothetically responsible for a certain number of false-positive serological reactions in man, especially in those subjects who are professionally exposed to animal lentiviruses. In the present paper particular reference is made to this last hypothesis which, if confirmed, would suggest a larger scale-utilization of more specific diagnostic tests for HIV infection in man, such as the immunoblotting techniques.