Case report of goose haemorrhagic polyomavirus in 4-day-old goslings indicating vertical transmissibility

Haemorrhagic nephritis and enteritis of geese (HNEG) is a fatal disease caused by goose haemorrhagic polyomavirus (GHPV). The aim of our study was to investigate a field outbreak of HNEG by pathological methods and real-time PCR assay using light upon extension (LUX PCR) with special regard to the possibility of vertical transmission. This is the first time that presence of GHPV was confirmed in goslings that died within 4 days after hatching showing typical symptoms of HNEG, which indicates vertical transmissibility as the shortest incubation period of HNEG is 6 days. The way of viral transmission is a key issue and thus the disease control measurements and HNEG epizootiology may be revised based on the findings of this study. Avian pathogens, nephritis, enteritis, LUX PCR, pathology Haemorrhagic nephritis and enteritis of geese (HNEG) is a fatal disease caused by goose haemorrhagic polyomavirus (GHPV). Since 1969, the first report of the disease by Bernath and Szalai (1970), the disease has spread through goose breeding areas of Germany (Schettler 1977; Miksch et al. 2002), Southern France (Schettler 1977; Guerin et al. 1999) and Hungary (Palya et al. 2004) with an epizootic pattern. The horizontal transmission of GHPV was earlier confirmed by Bernath and Szalai (1970) whereas the vertical route has not been proved; however, some observations posed the possibility that GHPV could be vertically transmitted. Firstly, Schettler (1980) supposed, that GHPV might have been circulating for almost a lifetime in the blood of infected geese, as HNEG was first detected in goslings immunised with reconvalescent anti-Derzsy disease sera obtained from apparently healthy geese. It may allow the GHPV to spread via infected eggs. Secondly, death of goslings at the age of 4 days was observed in flocks affected by HNEG, but GHP virions were not reported in these birds. Based on the death occurred at the age of 4 days, Palya et al. (2004) postulated the vertical transmission of HNEG because earlier studies showed that the shortest incubation period was 6 days after subcutaneous infection of 1-day-old goslings in an experimental infection study (Bernath and Szalai 1970). In the present report, investigation of a field outbreak among 4-day-old goslings is reported, providing further supportive data regarding the vertical transmissibility of GHPV. Materials and Methods