Classical Swine Fever (CSF)

Classical swine fever (CSF), also known as hog cholera, is a viral disease that poses significant threats to domestic pigs and wild boars worldwide. The disease has a long history and has been a subject of concern in the swine industry for decades. BioVenic, a leading company in the field of biotechnology, has been actively involved in research and development to combat CSF and mitigate its impact.

Etiology of CSF

CSF is caused by the classical swine fever virus (CSFV), which belongs to the Pestivirus genus within the Flaviviridae family. The CSFV is a single-stranded RNA virus with a spherical structure. The genome of CSFV is approximately 12.3 kilobases in length and encodes both structural and non-structural proteins essential for viral replication and pathogenesis.

CSFV does not possess the ability to persist in the environment or spread over long distances through airborne transmission. However, it can survive for a long time in a humid, low-temperature, protein-rich environment. In some cases, the virus has been observed to survive in frozen pork for several years.

Fig. 1 Schematic representation of CSFV viral structure and genome organization.¹

Transmission and Geographical Distribution

CSFV can be transmitted through various routes, including direct contact between infected and susceptible pigs, ingestion of contaminated materials (such as feed or water), and contact with fomites. Additionally, the virus can be spread by carriers, such as persistently infected pigs, and through biological vectors like ticks.

CSF has a worldwide distribution, affecting all regions of the globe. CSF outbreaks can occur in developed and developing countries, with varying degrees of economic impact. CSF occurs in Europe, Asia, Central, and South America, and parts of Africa. CSF is absent in North America, New Zealand, and Australia.

Effects and Pathogenesis of CSF

CSFV primarily targets domestic pigs and wild boars, causing a wide range of clinical manifestations and pathological changes. The severity of the disease can vary depending on factors such as the virulence of the virus strain, the age and immune status of the affected animals, and the presence of co-infections.

The pathogenesis of CSF involves the interaction between the virus and the host immune system. CSFV initially infects macrophages and dendritic cells, leading to viral replication and the subsequent dissemination of the virus throughout the body. The virus then targets lymphoid tissues, causing immunosuppression and impairing the host's ability to mount an effective immune response. This immune evasion strategy contributes to the persistence and chronicity of CSFV infections.

Signs and Symptoms of CSF

CSF presents a wide range of clinical signs and symptoms. Infected pigs may exhibit fever, depression, lethargy, anorexia, and reduced growth rates. Respiratory symptoms such as coughing and dyspnea can also occur. Gastrointestinal disturbances, including diarrhea and vomiting, may be observed. Additionally, CSFV infections can lead to hemorrhagic manifestations, such as petechiae, ecchymoses, and bloody diarrhea.

Diagnosis of CSF

BioVenic recognizes the importance of timely, accurate diagnosis for effective management of CSF and differentiation of other swine diseases with clinical manifestations similar to CSF. Our one-stop veterinary diagnostics solutions provide customers with a wide range of diagnostics methods, kits, and diagnostic reagent developments to detect swine fever virus infection.

• Antibody Detection
  ELISA and virus neutralization assay are used to detect swine fever virus-specific antibodies.
• Pathogen Detection
  Virus isolation and RT-qPCR can be used to detect swine fever virus.

Treatment of CSF

Currently, there is no specific antiviral treatment available for CSF. In countries without CSF, infected pigs are culled as soon as the disease is detected.

Fig. 2 Anti-CSFV drug candidates targeting the CSFV life cycle.¹

Prevention and Control of CSF

CSF can be prevented and controlled through vaccination, biosecurity measures, surveillance programs, and movement restrictions. BioVenic provides advanced vaccine development services to prevent CSFV, providing effective immunization options to swine producers and veterinarians worldwide. Vaccination strategies vary according to regional disease status and vaccination policies. In countries without CSF, preventive vaccination is prohibited. In CSF-endemic areas, highly effective live-attenuated vaccination against CSFV is widely used to control disease transmission.

Biosecurity practices are critical in preventing the introduction and spread of CSFV within and between pig farms. BioVenic actively collaborates with stakeholders to provide customized services to increase awareness and understanding of CSF prevention and control strategies.

• Strict measures, such as controlled access, disinfection protocols, and animal isolation, minimize the risk of CSFV transmission.
• Surveillance programs help in early detection and rapid response to outbreaks, enabling the timely implementation of control measures.

CSF continues to pose significant challenges to the swine industry globally. However, through collaboration, research, and implementation of effective control measures, the impact of CSF can be mitigated. To protect swine populations worldwide, BioVenic invests in research, diagnostics, and vaccine development. If you want to reach a cooperation with us, please feel free to contact us.

Reference

1. Fan, J., et al. "Anti-classical swine fever virus strategies." Microorganisms 9: 761. (2021).