Visna virus

The maedi - visna virus ( MVV ), and visna - maedi virus ( VMV ) or visna lentivirus ( VLV ) is an RNA virus belonging to the family of retroviruses ( Retroviridae ), genus lentiviruses. " Maedi " and " visna " derived from Icelandic names from (Icelandic: Maedi, " shortness of breath " and Visna, " fatigue" ), the two main forms of the virus caused by maedi visna disease.

The MVV is related to both the CAE virus of goats ( caprine arthritis- encephalitis virus ) as well as with the HIV virus in humans. The MVV was observed in Europe, North America, New Zealand and some African and South American countries. In Oceania, it is unknown.

This retrovirus causes chronic disease of sheep in both the lung ( maedi ) and the central nervous system ( visna ). Furthermore, chronic mastitis ( udder infections ) and arthritis are ( joint inflammation ) are known in these animals in rare cases. In each case the disease conditional virus is the same.

Infection occurs with intensive contact from sheep to sheep or via the milk ( lactogen ) from the mother to the Lamb. While the exchange of blood or other body secretions is probably necessary, but it is also known that the transmission is possible by droplet infection (via air ). Also the transmission by inoculation needles is discussed. Texel sheep, East Friesian milk sheep should have a special sensitivity to MVV infection.

The incubation period is at most about 5-6 years ( another source: 2-3 years). It is therefore a so-called slow virus infection ( English for " slow virus infection "). However, infected lambs can already show the first symptoms one month after birth.