Table 2.
Results obtained in experimental inoculation studies of bovine viral diarrhea virus in swine.
| References | BVDV Strain | Route of Inoculation | Animal Category | BVDV-Shedding | Viremia | Seroconversion (Dpi / % of Positive Pigs) | Consequences of Infection |
|---|---|---|---|---|---|---|---|
| Stewart et al., 1980 | - | Intranasal-oral | Pregnant sows | - | 7 dpi | 21 dpi / 100% | Intrauterine infection in one litter, fewer fetuses than corpora lutea. Not observed in fetuses |
| Terpstra and Wensvoort, 1988 | 76/4 and 77/5 strains | Natural infection | Sows and piglets | - | - | 35 dpi / (NA) | Piglets with clinical signs similar to CSF |
| Paton and Done, 1994 | 91/1 and 87/6 strains | Intrauterine | Pregnant sows | only congenital persistently infected fetus, for 2.5 years | 4–6 dpi in fetuses | variable in piglets, but all sows seroconverted | Intrauterine infection, some fetuses with no clinical signs, some with persistent congenital infection |
| Terpstra and Wensvoort, 1997 | Van Ee, Appel and Toering | Natural infection | Piglet | urine, oropharyngeal fluids, and semen of persistently infected boar | Observed | 30 dpi - 8 mo / (NA) | Congenital persistent infection, leukopenia, viral replication in several organs, clinical signs resembling chronic CSF |
| Kulcsar et al., 2001 | Oregon C24V strain | Intranasal and subcutaneous | Pregnant sows | Not observed | - | 28 dpi / 100% | No clinical signs on sows, birth of weak piglets with ruffled hair coat, splay leg, trembling, myoclonia, diarrhea, fever, death |
| Makoschey et al., 2002 | BVDV-2 | - | Piglets | - | - | Observed / 100% | Inapparent infection with a slight increase in body temperature in some piglets, viral replication in cells/organs. Slight leukopenia and/or thrombocytopenia |
| Walz et al., 2004 | BVDV-1 ncp | Intranasal inoculation | Pregnant gilts | - | 5–7 dpi | 21 dpi / 100% | No clinical signs observed in gilts or piglets; transplacental infection occurred in only one fetus from one gilt. No antibodies were found in piglets |
| Wieringa- Jelsma et al., 2006 | St. Oedenrode strain | Intranasal inoculation | Weaned pigs | 2–11 dpi | 7 dpi | 21 dpi / 100% | Not observed |
| Dos Santos et al., 2017 | BVDV-1 (Singer) cp | Oronasal inoculation | Weaned piglets | 10–25 dpi | Not observed | 25 dpi / 62.5% | Diarrhea, rough hair, nasal discharge |
| Nascimento et al., 2017 | BVDV-1 (Singer) cp | Oronasal inoculation | Weaned piglets | 5–24 dpi | Not observed | 25 dpi / 100% | Diarrhea, shivering, nasal discharge |
| Mechler et al., 2018 | BVDV-2 (VS-260) ncp | Oronasal and intrauterine inoculation | Pregnant gilts | No | Not observed | 20 dpi / 100% | Not observed |
| Pereira et al., 2018 | BVDV-2 (VS-253) cp | Oronasal inoculation | Pregnant gilts | 6–24 dpi | 3–12 dpi | 12–33 dpi / 70% | Thrombocytopenia |
| Gomes et al., 2019 | BVDV-2 (VS 260) ncp | Oronasal inoculation | Pregnant gilts | No | Not observed | 20 dpi / 100% | Not observed |
| Storino et al., 2020 | BVDV-2 (LVB 16557/15) ncp | Oronasal, intramuscular and intravenous inoculation | Boars | No | Not observed | 20–40 dpi / 12.5% | Lymphocytosis and monocytopenia |
Dpi: days post-inoculation; cp: cytopathic; ncp: non-cytopathic.; NA = not applicable.