Astroviruses were mainly detected in flocks suffering from enteric disorders; however, a few were detected in flocks without any symptoms of disease. This is in accordance with previous findings, and to date, the factors influencing astrovirus pathogenicity are unknown [22, 31] . Astrovirus was seldom detected in flocks older than 4 weeks. Recently, Jindal et al. observed astroviruses in poults up to 9 weeks of age [12] . In Poland, the maximum age of astrovirus-positive poults was 14 weeks, suggesting long-lasting astrovirus infection in turkeys or susceptibility to infection among older poults.