Classical Swine Fever (CSF) in Wild Boar: the Role of the Transplacental Infection in the Perpetuation of CSF

Abstract

Thirty-four pregnant wild sows and their unborn progeny derived from an endemically infected population in the district of Nordvorpommern (Mecklenburg-Western Pomerania) were investigated for classical swine fever virus (CSFV) and antibodies. During the last 2.5 years of the epidemic, 20 out of 34 pregnant wild sows investigated were serologically positive. No CSFV or viral RNA was detected in organs derived from these animals and their progeny. This indicates that young wild boars persistently infected by transplacental virus transmission do not play a crucial role in the perpetuation of CSFV in wild boar. Other factors seem to be more important for the establishment of CSF as well as for virus perpetuation in the population.

Classical Swine Fever—An Updated Review

“…Affected animals may develop antibodies that are in some cases only intermittently present and do not effect viral clearance. This, together with persistent infection, can play a role especially for affected wild boar populations [113,114,115], but also in endemically affected regions with constant virus circulation. Host rather than viral factors seem to play a role for the establishment of chronic infection [107].…”

“…While the sows often show only mild clinical signs, an infection depending on the stage of gestation, leads to absorption or mummification of the fetuses and to abortions or stillbirth [114,116,117,118,119,120,121,122,123]. When infected between days 50 and 70 of pregnancy, an immunotolerance phenomenon can be induced and persistently infected offspring are born.…”

Viral biocontrol: grand experiments in disease emergence and evolution

“…Classical swine fever virus was intentionally released several times in the 1950s to control the wild swine population on small islands in California. While an initial reduction in population size of approximately 80% was observed, on each occasion the virus disappeared after a few years, and was not able to persist in the wild swine population [7, 8]. In contrast, viruses have been used widely as biological pesticides in insect control, and are considered environmentally friendly compared to chemical pesticides.…”

Hunters’ acceptability of the surveillance system and alternative surveillance strategies for classical swine fever in wild boar - a participatory approach

“…This is mainly due to the potential transmissibility of the infectious agent from wild boar into domestic pig populations [1–3]. Also, strict movement regulations affecting domestic pig holdings are implemented for the holdings in the restriction zone around a CSF outbreak according to EU and national legislation.…”