Jaagsiekte sheep retrovirus (JSRV) is a type of retrovirus that infects sheep and causes a contagious lung disease known as ovine pulmonary adenocarcinoma (OPA), also called jaagsiekte. JSRV belongs to the Retroviridae family and the genus Betaretrovirus. The virus primarily targets the respiratory system, causing tumors to form in the lungs, which ultimately leads to severe breathing difficulties and respiratory failure.
JSRV is spread through respiratory secretions, which can be transmitted via aerosols or direct contact between infected and susceptible sheep. The virus primarily affects adult sheep, with an incubation period ranging from a few months to several years before clinical signs of the disease manifest.
The characteristic symptoms of OPA caused by JSRV include a persistent cough, rapid and labored breathing, weight loss, lethargy, and a decline in overall health. As the disease progresses, affected sheep may exhibit a tendency to isolate themselves from the flock due to difficulty in breathing.
Currently, there is no known cure for JSRV or OPA, and the disease is usually fatal. Control measures primarily focus on preventing the spread of the virus, such as isolation or culling of infected animals, maintaining good hygiene practices, and vaccination against other respiratory pathogens that may exacerbate the development of the disease.
The study of JSRV has also contributed to scientific research and understanding of human lung cancer, as the virus has been found to share similarities in genetic mechanisms and oncogenic pathways.
