Virulent Properties of Russian Bovine Viral Diarrhea Virus Strains in Experimentally Infected Calves

Table 1

Pathogenic properties of bovine viral diarrhea virus (BVDV) noncytopathic strains of type 1 after aerosol challenge of 4–6-month-old calves with the dose of 6 log₁₀ TCD₅₀.

Name of the strain/isolation source	Subtype	Manifestation form of the disease	Time of leukopenia (days postinfection), the lowest concentration of leukocytes (cells/mm^3, for )	Presence of antibodies to BVDV	Type of organ system with BVDV genome
Bison/calf lung	1d	Acute (acute respiratory infection, diarrhea)	4–9, 2700 ± 300	+	Lymphoid (spleen, pulmonary lymph nodes), respiratory (lungs), and intestinal (small intestine, duodenum, ileum, and mesenteric lymph nodes)
T2/bull sperm	1a	Subclinical	4–8, 3500 ± 300	±	Lymphoid and respiratory (spleen, pulmonary lymph nodes)
Bor/heifer blood serum	1b	Subclinical	3–9, 3700 ± 300	+	Lymphoid (spleen, mesenteric lymph nodes, Peyer’s patches)

, mean value.
, 95% confidence interval.
, number of animals.
The value is below those for T2 and Bor strains according to the Mann-Whitney test and Student’s -test at .