Related Experiment Videos
[Swine fever: a changing clinical picture]
Tijdschrift Voor Diergeneeskunde
|April 1, 1985
Summary
Low-virulence classical swine fever strains cause subtle symptoms, hindering early detection. This allows the virus to persist, even in vaccinated herds, through asymptomatic infected piglets born from sows with intrauterine infections.
Area of Science:
- Veterinary Virology
- Epizootiology
- Swine Disease Control
Background:
- Classical swine fever (CSF) outbreaks are often characterized by typical disease signs.
- However, low-virulence virus strains can cause atypical presentations, complicating diagnosis.
- The current epizootic in the Netherlands involves both high and low virulence CSF strains.
Purpose of the Study:
- To elucidate the clinical picture of low-virulence CSF strains.
- To describe the epizootiology of these strains in the Netherlands.
- To understand the challenges in early detection and control of CSF due to atypical presentations.
Main Methods:
- Experimental induction of infections with CSF virus strains.
- Field investigations of outbreaks in swine herds.
- Analysis of clinical signs, epizootiological data, and intrauterine infection rates.
Main Results:
- Absence of typical disease signs in outbreaks caused by low-virulence strains.
- Intrauterine infections were observed in a significant proportion of pregnant sows (up to 43%).
- Asymptomatic piglets can harbor the virus for extended periods, facilitating persistence.
Conclusions:
- Low-virulence CSF strains pose a significant challenge for early detection in swine populations.
- Intrauterine transmission and prolonged asymptomatic shedding by piglets contribute to virus persistence.
- Effective control strategies must account for these atypical presentations and transmission routes.