Descriptive summary of the classical swine fever control in wild boar in Germany since 2005

Abstract

Classical swine fever (CSF) in wild boar repeatedly appeared in different federal states of the Federal Republic of Germany since 1995, from which it has been successfully eradicated sometimes fast, sometimes in a more time taking way using oral immunization as a main element of control. Since 2005 the cases focused solely on North Rhine-Westphalia and Rhineland-Palatinate. In the present study, therefore, the situation of CSF in wild boar has been closely investigated concerning the period 2005 to 2012 in these two regions. It is noteworthy that in this period two different variants of the virus subtype 2.3 occurred in two regionally defined areas of the "Eifel" and "Westerwald" as well as in the "Pfalz". The two Federal States have undertaken extensive oral vaccination campaigns and surveillance activities, which enabled an assessment of the existing virus prevalence and serological prevalence in the different regions. After an initial high serological prevalence, caused probably by interaction of infection and vaccination, the serological levels stabilized seasonally adjusted in a range from 50 to 60% in almost all areas. The vaccination campaigns have been maintained by both Federal States over a period of at least 2.5 years after virus has been detected for the last time. In consequence Germany as a whole has been recognized for the first time to be officially free from CSF in wild boar. By genotyping of virus isolates it has been demonstrated that the virus changed over time and played a role in the outbreak area "Westerwald".