Pestivirus

A genus of viruses in the family Flaviviridae

Pestivirus is a genus of viruses in the family Flaviviridae. These viruses are known to infect a variety of mammals, primarily livestock, and are responsible for significant economic losses in the agricultural industry due to their impact on animal health.

Virology

Pestiviruses are small, enveloped viruses with a single-stranded, positive-sense RNA genome. The genome is approximately 12.3 kilobases in length and encodes a single polyprotein that is processed into structural and non-structural proteins. The structural proteins include the capsid protein C and the envelope glycoproteins Erns, E1, and E2.

Genome Organization

The genome of pestiviruses is organized into a single open reading frame (ORF) flanked by untranslated regions (UTRs) at both the 5' and 3' ends. The 5' UTR contains an internal ribosome entry site (IRES) that facilitates translation of the viral polyprotein.

Replication Cycle

Pestiviruses enter host cells through receptor-mediated endocytosis. After entry, the viral RNA is released into the cytoplasm, where it is translated into a polyprotein. This polyprotein is cleaved by viral and host proteases to produce mature viral proteins. Replication of the viral RNA occurs in the cytoplasm, and new virions are assembled and released from the host cell.

Pathogenesis

Pestiviruses are known to cause a range of diseases in livestock, including Bovine Viral Diarrhea (BVD) in cattle, Classical Swine Fever (CSF) in pigs, and Border Disease in sheep. These diseases can lead to symptoms such as fever, diarrhea, respiratory distress, and reproductive failure.

Bovine Viral Diarrhea

BVD is characterized by diarrhea, mucosal lesions, and immunosuppression in cattle. It can also cause reproductive issues such as abortion and congenital defects.

Classical Swine Fever

CSF, also known as hog cholera, is a highly contagious disease in pigs that can lead to high mortality rates. Symptoms include fever, skin lesions, and neurological signs.

Border Disease

Border Disease affects sheep and is characterized by "hairy shaker" lambs, which exhibit tremors and abnormal wool growth.

Epidemiology

Pestiviruses are distributed worldwide and have a significant impact on livestock health and productivity. Transmission occurs through direct contact with infected animals, contaminated feed, and fomites. Vertical transmission from mother to offspring is also common.

Prevention and Control

Control of pestivirus infections involves a combination of vaccination, biosecurity measures, and management practices. Vaccines are available for BVD and CSF, and efforts to control these diseases focus on preventing the introduction and spread of the virus within herds.

Related pages

• Flaviviridae
• Bovine Viral Diarrhea
• Classical Swine Fever
• Border Disease