[Descriptive summary of the classical swine fever control in wild boar in Germany since 2005]. / Zusammenfassende Darstellung der Schweinepestbekämpfung beim Schwarz- wild in Deutschland seit dem Jahr 2005.

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".

Consideration of different outbreak conditions in the evaluation of preventive culling and emergency vaccination to control foot and mouth disease epidemics.

In recent foot and mouth disease outbreaks, many healthy animals have been culled to prevent disease transmission. Emergency vaccination is discussed as an alternative to culling of unaffected animals. A spatial and temporal Monte-Carlo simulation model was used to compare preventive culling and emergency vaccination. Different outbreaks are described using additional influence factors such as airborne spread, farm density, type of index-case farm and delay until establishment of the control strategies. The fewest farms were infected establishing a combined strategy including a 1 km preventive culling and 1-10 km emergency vaccination zone around each outbreak farm. Taking the number of culled and vaccinated farms into account, vaccination around the first diagnosed farm combined with the baseline strategy (culling of outbreak farms, protection and surveillance zone, contact tracing) is to be preferred. In the present study, emergency vaccination was an effective control strategy especially in densely populated regions.

Highly pathogenic avian influenza virus (H5N1) in frozen duck carcasses, Germany, 2007.

We conducted phylogenetic and epidemiologic analyses to determine sources of outbreaks of highly pathogenic avian influenza virus (HPAIV), subtype H5N1, in poultry holdings in 2007 in Germany, and a suspected incursion of HPAIV into the food chain through contaminated deep-frozen duck carcasses. In summer 2007, HPAIV (H5N1) outbreaks in 3 poultry holdings in Germany were temporally, spatially, and phylogenetically linked to outbreaks in wild aquatic birds. Detection of HPAIV (H5N1) in frozen duck carcass samples of retained slaughter batches of 1 farm indicated that silent infection had occurred for some time before the incidental detection. Phylogenetic analysis established a direct epidemiologic link between HPAIV isolated from duck meat and strains isolated from 3 further outbreaks in December 2007 in backyard chickens that had access to uncooked offal from commercial deep-frozen duck carcasses. Measures that will prevent such undetected introduction of HPAIV (H5N1) into the food chain are urgently required.

Retrospective analysis of the oral immunisation of wild boar populations against classical swine fever virus (CSFV) in region Eifel of Rhineland-Palatinate.

In the present study the effect of control measures implemented during the classical swine fever (CSF) epidemic in wild boar in the Eifel region of the German federal state of Rhineland-Palatinate from 1999 to 2005 was assessed. During the first 3 years after official confirmation of virus detection these measures comprised intensive hunting, especially of young animals and hygiene measures. Subsequently oral immunisation (o.i.) using a modified live virus vaccine was introduced as an additional control tool. All shot wild boar from the restricted area were tested virologically and serologically for CSF. The laboratory results from over 110,000 animals accompanied by information about age, gender and geographical origin of the animals were collected in a relational database. In total about 82% of all virologically positive wild boars were piglets, thus confirming the importance of this age group in the perpetuation of the epidemic. An analysis of the hunting bag showed that piglets were underrepresented compared to older animals throughout the eradication programme. This finding indicated that hunters did not comply with the control strategy of intense targeting of young animals. Before as well as after the implementation of o.i. a significantly higher virological prevalence and a significantly lower serological prevalence were observed in piglets compared to yearlings and adults. Shortly after the beginning of the vaccination campaign in February 2002 CSFV prevalence decreased significantly whereas the serological prevalence increased markedly in all age classes. In order to test the influence of age and vaccination on the serological prevalence a logistic regression model was used. Our results strongly suggest that under the field conditions in the Eifel region vaccination against CSFV had a crucial influence on the increase of seroprevalence rate and the elimination of CSFV. The last virus-positive pig was found 13 months after start of o.i.