Lentiviruses of sheep and goats


The general objectives of the research project are: to analyse the viral factors involved in the virulence and pathogenesis of ovine and caprine lentiviruses in their natural hosts; to study the genetic variability of these lentiviruses in natural infections; to use this information for epidemiological purposes and the development of strategies to control disease caused by lentivirus infections; to improve and to standardize diagnostic procedures.


Sheep and goat were identified as seropositive during seroepidemiologic screenings. The Finnish sheep lentiviruses were genetically close to the prototype ovine maedi-visna viruses. The lentivirus detected from the Finnish goat aligned with the cluster of the Finnish ovine viruses, demonstrating a natural sheep-to-goat transmission. The Finnish small ruminant lentiviruses constituted a new subtype within the diverse maedi-visna virus group. Analysis of the Finnish small ruminant lentiviruses showed a correlation between molecular and epidemiological data confirming a close linkage between the infected farms and supporting the idea of one importation as a source of infection.


lentiviruses, phylogenetic relationship, epidemiology, cross species infection, control program, lentivirukset, epidemiologia, kontrolliohjelmat

Responsible project leader:

Sihvonen, Liisa, Research Director, Evira and Professor in Veterinary Virology, University of Helsinki, Department of Basic Veterinary Sciences

Person at Evira responsible for the project:

Sihvonen Liisa, Research Director and Professor in Veterinary Virology, University of Helsinki, Department of Basic Veterinary Sciences

In cooperation with:

EU neuroprion - Network of Excellence of the Prion diseses (TSE);
Helsingin yliopisto, Eläinlääketieteellinen tiedekunta

Project status:


Year of commencement:


Year of completion:



Laamanen, I., M. Jakava-viljanen, L. Sihvonen: Genetic Characterization of maedi-visna virus (MVV) detectected in Finland. Veterinary Microbiology 119 (2007) 357-365.
Laamanen, I., Jakava-Viljanen, M., Sihvonen, L. Identification of small-ruminant lentiviruses in clinical specimens by PCR followed by genetic typing using sequence analysis. Leitão, A., Martins, C. (eds.): Proceedings of the 7 th International Congress of Veterinary Virology. European Society for Veterinary Virology (ESVV), 24 th-27 th September 2006, Faculdade de Medicina Veterinária, Lisboa, Portugal, p. 232.
Laamanen, I. and Sihvonen, L.: Genetic relationships of small-ruminant lentiviruses identified in Finland. 6 th International Congress of Veterinary Virology, Virus Persistence and Evolution, 24 th – 27 th , August 2003, Saint-Malo, France, Abstract
Sihvonen, L., Nuotio, L., Rikula, U., Hirvelä-Koski V. and Kokkonen U-M.: Preventing the spread of maedi-visna in sheep through a voluntary control programme in Finland. Prev. Vet. Med. 2000, 47, 213-220.
Sihvonen, L., Laamanen, I., Rikula, U., Kokkonen, U., Nuotio, L, and Veijalainen, P.: Small Ruminant Lentivirus Infection and Characterization of the Finnish Isolates. Virologipäivät 2000 March 16-17,2000 Oulu. Abstract O6.
Nuotio, L, Sihvonen, L., Rikula, U., Hirvelä-Koski V. and Kokkonen, U.-M.: Initial spread of maedi-visna into a new area. Int. Conference and Workshop on Animal Retroviruses, Cambridge, UK, September 3-6, 2000. Abstract O28 p.40.
Sihvonen, L.: Maedi-visna Suomessa. Ajankohtaista eläinten tarttuvista taudeista. Teemapäivä 11.5.2000. MMMEEO, EELA 4ss.
Sihvonen, L., Hirvelä-Koski V., Nuotio, L. and Kokkonen Ulla-Maija: Serological survey and epidemiolgical investigation of Maedi-Visna in Finland. Veterinary Microbiology 1999, 65, 265-270.
Sihvonen, L.: Ovine lentiviruses and diagnosis. Cost 834. Lentiviruses of small ruminants: pathogenesis, diagnostics and prevention. Proceedings and abstracts of the first four meetings of working groups between February 1998 and August 1998. Report. European Communities, 1999, pp. 45-46.
Sihvonen, L.: Ovine Lentivirus Infection and Diagnosis. Cost Action 834, WG3 meeting in Edinburgh 7.3.1998, Abstract 1 p.

Project is financed by:

Cost Action 834 (1997- 2002);
Ministry of Agriculture and Forestry (grant 4657/39/98, 1999-2002);