… The main target cells of MVV are of the monocyte/macrophage lineage and it does not
infect Tlymphocytes or cause immune suppression like human immune deficiency virus (HIV).
In spite of a fairly good immune response, including both neutralizing antibodies and
cytotoxic T lymphocytes, the virus persists in the host and establishes a life-long infection.
There are strong indications that the pathological lesions are … The viruses were shown to
be serologically related, and early transmission experiments indicated that visna and maedi …

1.1 Introduction Maedi-visna virus was originally described in Iceland as an aetiologic agent
of chronic interstitial pneumonia (maedi) and demyelinating leukoencephalomyelitis (visna)
in sheep (Sigurdsson, 1954., Sigurdsson & Palsson, 1958., Sigurdsson et al, 1952., 1957).
Maedi-visna is a relatively common infection of sheep in most parts of the world (Adams et
al, 1984), but the incidence of clinical disease is relatively low. However in the last decade
lentiviral infections of both man, the human immunodeficiency virus (HIV), and other animals …