The emergence and nature of different strains of infectious bronchitis virus (IBV) in Europe are described. Infectious bronchitis (IB) is the most important endemic viral respiratory disease where highly pathogenic Newcastle disease and avian influenza are not present. IB was first described in the UK in 1948 and identified as Massachusetts type. In the 1970s and 80s new serotypes were reported in Holland and elsewhere and new vaccines were developed. The 1990s saw the emergence of the major variant commonly called 793B, again needing a new vaccine. Two novel types have been recognised since 2000, Italy 02 and QX. Italy 02 appears to be well controlled by the use of two different live vaccines (H120 and the 793B-related 4/91) while for QX, associated with nephritis in young birds and silent layers, new vaccines are in development. The use of two vaccines as above is a widely used protocol and is capable of protecting against a wide range of different types. Alternative approaches to IB vaccination are discussed. The importance of constant surveillance for prevalent and novel IBV types is emphasised and the value of experimental infections in chickens to determine the pathogenesis and pathology of new types in addition to testing efficacy of vaccines is outlined.
This article reports a survey on turkey astrovirus (TAstV) and turkey coronavirus (TCoV) infections with RT-PCR in 17 turkey flocks affected by acute enteritis and two apparently normal turkey flocks located in the Southeastern region of Brazil by PCR (TAstV and TCoV). Seven out of the 17 affected flocks were positive for TAstV and 14 for TCoV, with seven co-infections. In one of the two apparently normal flocks, a TAstV-TCoV co-infection was found. Although a definitive association of these agents and the signs can not be made, the implications of these findings are discussed.