“Classical swine fever (CSF) remains one of the most contagious and economically significant viral diseases, impacting both domestic pigs and wild boars globally,” said Dr. K. Kumanan, former Director of Research, Tamil Nadu Veterinary and Animal Sciences University (TANUVAS).
Presenting his paper at the Symposium on Strategies to Combat Economically Important Porcine & Poultry Viruses in India, organized by the BRIC-National Institute of Animal Biotechnology (NIAB) in Hyderabad on 3-4 October 2024, Dr. Kumanan highlighted the persistent threat of CSF, despite eradication efforts in countries like Canada, the United States, Australia, and New Zealand. In India, the disease remains prevalent, causing substantial economic losses to the pig farming industry.
CSF, caused by the CSF virus (CSFV), a member of the genus Pestivirus under the family Flaviviridae, affects both domestic and wild pigs. Dr. Kumanan emphasized the severe impact of acute CSF, which is characterized by high fever, leucopenia, uncoordinated movements, and cyanosis of the skin, leading to significant mortality rates, ranging from 8.2% to 45% depending on the virulence of the virus and the age of the infected animal.
The chronic form of CSF, however, presents a slower progression, often manifesting as stunting, intermittent pyrexia, diarrhea, and anorexia. This form of the disease occurs when infected pigs survive beyond the acute phase, particularly if they fail to develop an effective immune response. Dr. Kumanan pointed out that the disease is closely related to other pestiviruses, including the Bovine viral diarrhea virus and Border disease of sheep.
Rabbit attenuated C-strain vaccine, he noted, remains the most widely used vaccine to control CSF, offering long-lasting immunity. However, the availability of potent vaccines is limited by ethical issues, high costs, and logistical challenges related to vaccinating free-ranging pigs, which are often unmonitored and unvaccinated.
“The porosity of India’s borders and lack of strict animal movement controls exacerbate the spread of CSF,” Dr. Kumanan explained, pointing out that better surveillance and vaccination protocols are critical to halting the spread of the disease.
He outlined several strategies for CSF control, including:
1. Constant surveillance to identify seronegative pigs and establish disease-free zones.
2. Rapid diagnosis and elimination of infected animals.
3. Movement restrictions to prevent the spread of the virus through animal contact.
4. Serological monitoring of pigs in intensive farming systems.
5. Regular vaccination programs in endemic areas.
6. Assessing post-vaccinal immune responses to ensure vaccine efficacy.
7. Developing newer vaccines and implementing DIVA (Differentiating Infected from Vaccinated Animals) strategies to improve control measures.
Dr. Kumanan concluded by emphasizing the need for a coordinated, multifaceted approach that integrates surveillance, vaccination, and rapid diagnostics to effectively manage and control CSF outbreaks in India.
–Raja Aditya
