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Porcine Parvovirus
Parvoviridae
| Question | Answer |
|---|---|
| Virtually all sows in a herd are naturally infected before their second pregnancy hence reproductive problems are observed mostly in... | primiparous gilts |
| SMEDI present and how many serotypes are present? | ONE |
| What are two ways the virus can be transmitted? | Oronasal and venereal transmission due to infected boars shedding the virus in the semen for a couple of weeks |
| Are all embryos infecetd at the same time in transplacental infection? | NO...each one has a different placenta but a spread eventually occurs and as a result DEATH AT DIFFERENT STAGES OF PREGNANCY IS TYPICAL |
| Where does PPV have a predilection site for? | mitotically active cells, esp capillary endothelial cells and leukocytes |
| What is the HALLMARK of PPV infection? | small litters with dead fetuses (mostly mummified, some stillborn) and healthy piglets |
| T/F. Abortions are common. | FALSE. They are uncommon. |
| What happens to embryos less than 30 days old? | dies and is resorbed |
| What happens to early fetus infected? (30-70 days) | die and are mummified |
| What happens to a late fetus that is infected? | develop lesions and survive to produce antibody to PPV |
| When does immunocompetence of pig fetuses start? | 55-70 days |
| What are immunotolerant pigs? | They are piglets that are born as infected but immune piglets that can pass the virus continuously or intermittently |
| How long can maternally immunity last? | 4 months but in some pigs it can last up to 6-9 months |
| Is immunity lifelong? | YES |
| Is is possible for some gilts to be seronegative at mating time to be susceptible to infection? | YES |
| What is different about the porcine parvovirus from the others? | It causes persistent infection with CHRONIC shedding. |