MOLECULAR EPIDEMIOLOGY OF PRRS VIRUS ISOLATES FROM A PIG-DENSE REGION IN LOWER SAXONY, GERMANY

摘要

PRRSV is endemic almost world wide (1). In Germany, control of the disease is attempted by vaccination. For this, two modified live vaccines (MLV) containing a North American (NA) or a European (EU) genotype virus strain, respectively, and two inactivated vaccines are being used. The province of Lower Saxony is located in the Northern part of Germany, bordering with the Netherlands. It is one of the regions with the highest pig density in Europe. In Lower Saxony the population actually amounts to 8.2million pigs with an average density of 298 pigs per 100 acre. In this study molecular epidemiology of PRRS virus isolates from 50 herds in this region was analysed. The pig density in the counties where most of the samples originated from is between 500 and 1400 pigs per 100 acre (2, 3) The aims of the study were 1) to determine the influence of the MLV on the PRRSV isolates circulating in the field, and 2) to determine if the EU genotype wild-type isolates from these herds form distinct genetic clusters that allow to differentiate them from wild type field isolates occurring in other European countries.