Classical Swine Fever | Control
Vaccination
Most of the attenuated vaccines are based on the China-strain (C-strain) of CSF virus. C-strain vaccines are currently used world-wide. It induces high titers of neutralizing antibodies and it is safe for use in pregnant animals. The major restriction to vaccination with attenuated strains such as C-strain is that the antibodies induced by vaccination cannot be distinguished from antibodies induced by natural infection. This disadvantage is extremely important considering its implications for global trade.
There is currently a significant effort to develop "marker vaccines", which are subunit vaccines. A recombinant viral glycoprotein E2 expressed in a baculovirus system has been studied for this end. The advantage here is that vaccinated animals could easily be distinguished from naturally infected ones based on a different viral protein used as diagnostic antigen.
Control policies
In countries where CSF is endemic vaccination is usually extensively used to prevent losses, but it is not effective as an approach for eradication of the disease. Although vaccination with attenuated strains such as C-strain is efficient to prevent disease it allow maintenance of sub-clinical infection with virulent strains. Therefore, restriction for international trade is imposed on countries that employ vaccination.
Control of outbreaks in areas without vaccination is usually based on the following procedures: depopulation of infected pig herds and infected contact or neighboring herds, epidemiological investigation, clinical and virological investigations, movement restrictions for live pigs, pig meat and other vectors that can transmit the disease.
Economic Impact >>
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