A long-term serological survey on Aujeszky's disease virus infections in wild boar in East Germany.

Between 1985 and 2008, a total of 102,387 wild boar sera originating from Eastern Germany covering an area of 108 589 km2 were tested for the presence of Aujeszky's disease virus (ADV)-specific antibodies. From 1985 until 1991 and from 1992 until 2008, wild boar sera were exclusively investigated using either conventional seroneutralization assays (n=39 621) or commercial gB and full antigen ELISAs (n=62,766), respectively. Spatial-temporal analysis revealed an increasing ADV seroprevalence from 0·4% to 15·9%, on average, during the 24-year observation period that went along with a continuous spread of the infection in a western direction. During 2006 and 2008, 18% of the 66 affected districts had ADV seroprevalences >30%. There was a significant correlation between ADV seroprevalence and the hunting index of population density (HIPD) of wild boar in the entire study area, although this did not hold true for some regions. Seroprevalences did not differ between sexes but were age-dependent. East Germany has been officially free of Aujeszky's disease (pseudorabies) in domestic pigs since 1985. Although a risk for domestic pigs cannot be completely ruled out, experience has shown that ADV in domestic pigs could be eliminated although the virus was present in the wild boar population. Despite increasing ADV seroprevalence in the East German wild boar population no spillover infections from wild boar to domestic pigs have been reported. To further trace ADV infections in the wild boar population in Germany, a nationwide serological monitoring programme should be implemented.

Active surveillance for avian influenza virus infection in wild birds by analysis of avian fecal samples from the environment.

A total of 1991 environmental samples of fresh avian feces and urine from several aquatic bird species in a coastal area of Northeast Germany were examined for the presence of avian influenza viruses (AIV). By real-time reverse-transcriptase polymerase chain reaction, specific for an M gene of influenza A viruses, none of 659 duck samples and only 11 (0.9%) of 1,268 geese and swan samples tested positive. Two of these were identified as H5N2 viruses of low pathogenicity. Conventional cloacal and oropharyngeal swab samples (n=1,402) collected in an adjacent coastal region in Northeast Germany from comparable species of captured or hunted birds, yielded a similar detection rate (3/901; 0.4%) for AIV-specific RNA in geese and swans, but a higher rate (4/309; 1%) for ducks. No virus isolates were obtained from either set of samples. Collection of environmental avian samples was simple and cost effective and also allowed us to regulate sample sizes over time. A species assignment of these samples was possible, provided that close presampling observation of birds at the sampling sites was secured. Environmental sampling to monitor AIV in wild bird populations may be a valid alternative to the more-invasive and capture-dependent methods based on cloacal sampling.

Highly Pathogenic Avian Influenza H5N8 in Germany: Outbreak Investigations.

Epidemiological outbreak investigations were conducted in highly pathogenic avian influenza virus of the subtype H5N8 (HPAIV H5N8)-affected poultry holdings and a zoo to identify potential routes of entry of the pathogen via water, feedstuffs, animals, people, bedding material, other fomites (equipment, vehicles etc.) and the presence of wild birds near affected holdings. Indirect introduction of HPAIV H5N8 via material contaminated by infected wild bird seems the most reasonable explanation for the observed outbreak series in three commercial holdings in Mecklenburg-Western Pomerania and Lower Saxony, while direct contact to infected wild birds may have led to outbreaks in a zoo in Rostock and in two small free-range holdings in Anklam, Mecklenburg-Western Pomerania.