Classical Swine Fever—An Updated Review

Abstract

Classical swine fever (CSF) remains one of the most important transboundary viral diseases of swine worldwide. The causative agent is CSF virus, a small, enveloped RNA virus of the genus Pestivirus. Based on partial sequences, three genotypes can be distinguished that do not, however, directly correlate with virulence. Depending on both virus and host factors, a wide range of clinical syndromes can be observed and thus, laboratory confirmation is mandatory. To this means, both direct and indirect methods are utilized with an increasing degree of commercialization. Both infections in domestic pigs and wild boar are of great relevance; and wild boars are a reservoir host transmitting the virus sporadically also to pig farms. Control strategies for epidemic outbreaks in free countries are mainly based on classical intervention measures; i.e., quarantine and strict culling of affected herds. In these countries, vaccination is only an emergency option. However, live vaccines are used for controlling the disease in endemically infected regions in Asia, Eastern Europe, the Americas, and some African countries. Here, we will provide a concise, updated review on virus properties, clinical signs and pathology, epidemiology, pathogenesis and immune responses, diagnosis and vaccination possibilities.

Low CD4/CD8 ratio in classical swine fever postnatal persistent infection generated at 3 weeks after birth

“…It is noteworthy that some infected pigs in the present work, including some of persistently infected animals, developed vesicular lesions, ulcerations and skin desquamation after 3 weeks post infection. This fact highlights the ability of CSFV in its interaction with the host to generate a wide variety of clinical signs (Blome et al., ; Ganges et al., ; Tarradas et al., ). Therefore, the CSF persistent forms may manifest clinical signs so far never described.…”

“…The most relevant histopathological finding in the tonsil are congestion of the blood vessels along with focal to diffuse areas of haemorrhage (Malswamkima, Rajkhowa, Chandra, & Dutta, ). Necrosis and depletion of lymphocytes, haemorrhages and tonsillitis have also been described (Blome et al., ; Quezada et al., ). Notably, despite the high viral load detected in the tonsils from persistently infected pigs, neither macroscopic nor histopathological lesions were found, a fact that may hinder the detection of this type of infected animals.…”

Positive selection pressure on E2 protein of classical swine fever virus drives variations in virulence, pathogenesis and antigenicity: Implication for epidemiological surveillance in endemic areas

“…Depending of the virulence of the CSFV strains, together with host‐related factor such as age, breed and immune status, different clinical manifestation of CSF could be presented (Moennig, Floegel‐Niesmann, & Greiser‐Wilke, ). Thus, three main forms of the disease have been defined, acute (transient or lethal), chronic and persistent course, each of them showing a high variability of the clinical signs (Blome, Staubach, Henke, Carlson, & Beer, ).…”

Vaccines the tugboat for prevention-based animal production

“…It is an acute, highly infectious viral disease of swine of all ages characterized by rapid and sudden onset, high morbidity, mortality, and generalized hemorrhages (Blome et al, 2017). It has a massive impact on pig industries and is therefore notifiable to the OIE (2017).…”