Changes

==Transmission and Pathogenesis==

==Transmission and Pathogenesis==

In field cases of CSFV, transmission is mainly oronasal by direct or indirect contact with infected pigs. Infected feed or pork products may also cause spread of disease, and transmission in semen can occur. Once the virus gains entry to the host an incubation period of around 7 days ensues, but this may vary from 4-10 days. Initially, virus infects the epithelial cells of the tonsillar crypts before spreading via the lymphatics to regional lymph nodes. From here, classical swine fever virus enters the blood stream and then replicates in the spleen, bone marrow and lymph nodes before spreading to further tissues. Replication in the endothelial cells of blood vessels leads to apoptosis, causing superficial and internal haemorrhages. CSFV also causes a thrombocytopenia which contributes to haemorrhage by impairing primary haemostasis. In acute CSF this angiopathy causes pig death in association with shock and the febrile response. Surviving swine go on to develop a chronic form of the disease where joint and enteric lesions are seen resulting from tissue infarction.

In field cases of CSFV, transmission is mainly oronasal by direct or indirect contact with infected pigs. Infected feed or pork products may also cause spread of disease, and transmission in semen can occur. Once the virus gains entry to the host an incubation period of around 7 days ensues, but this may vary from 4-10 days. Initially, virus infects the epithelial cells of the tonsillar crypts before spreading via the lymphatics to regional lymph nodes. From here, classical swine fever virus enters the blood stream and then replicates in the spleen, bone marrow and lymph nodes before spreading to further tissues. Replication in the endothelial cells of blood vessels leads to apoptosis, causing superficial and internal haemorrhages. CSFV also causes a thrombocytopenia which contributes to haemorrhage by impairing primary haemostasis. In acute CSF this angiopathy, in association with shock and pyrexia, leads to death. Surviving swine go on to develop a chronic form of the disease where tissue infarction results in joint and enteric lesions.

The outcome of transplacental infection of foetuses depends largely on the point of gestation and may result in abortions, stillbirths, mummifications, malformations or the birth of weak or persistently viraemic piglets. Although persistently infected piglets may be clinically normal at birth, they grow poorly, excrete virus over long periods and invariably die from CSF.

The outcome of transplacental infection depends largely on the point of gestation and may result in abortions, stillbirths, mummifications, malformations or the birth of weak or persistently viraemic piglets. Although persistently infected piglets may be clinically normal at birth, they grow poorly, excrete virus over long periods and invariably die from CSF.

==Diagnosis==

==Diagnosis==