Genetic diversity and distribution of bovine pestiviruses (<i>Flaviviridae: Pestivirus</i>) in the world and in the Russian Federation

Abstract

The genus Pestivirus of the family Flaviviridae includes 11 species. Bovine pestiviruses are the causative agents of viral diarrhea/mucosal disease and include three genetically distinct species: pestivirus A (BVDV-1), B (BVDV-2), and H (BVDV-3). The number of BVDV-1 subtypes is 21, BVDV-2 – 4, and BVDV-3 – 4, which complicates the diagnosis of associated diseases, reduces the effectiveness of vaccination and control programs. We performed the search in the PubMed, Web of Science, Scopus, eLIBRARY.RU databases for articles published in 2000–2021. Pestivirus A is distributed everywhere, although the largest number of subtypes was found in cattle in Italy and China. The virus is widespread in the Central region of the Russia (subtypes 1a and 1m). In Siberia, eleven subtypes circulate among native and imported animals: 1a (5%), 1b (35%), 1c (5%), 1d (10%), 1f (20%), 1g, 1i (both 2.5%), 1j, 1k, 1p, and 1r (all for 5%). Pestivirus B subtype is more virulent, found less frequently and mainly in the North and South America, in some European countries, and in Asia. Three subtypes have been identified in Siberia: 2a (25%), 2b (10%), and 2c (5%). Pestivirus H circulates in Europe, Asia and South America. The main route of entry is contaminated biological products. In Russia, BVDV-3 of the Italian-Brazilian group (3a) was detected in 7 lots of fetal bovine serum. The role of the virus in the occurrence of respiratory diseases in calves, abortion, systemic infection and enteritis in calves and adult animals has been established. The source of the virus in such cases was a contaminated modified live vaccine.

Keywords

• pestiviruses
• bovine viral diarrhea/mucosal disease
• genetic polymorphism
• species
• subtypes
• spread