Astroviruses (AstVs) are emerging, potentially zoonotic pathogens, associated with enteric and neurological signs in various animal species. In pigs, five lineages have been identified, porcine AstVs (PoAstVs) 1$–$5. We now report PoAstV5-associated atrophic enteritis in a colostrum-deprived (CD) pig and a similar disease in field cases of enteritis. Four newborn CD piglets were housed under biosafety level 2 conditions and monitored for the presence of PoAstV RNA in rectal swabs and tissues. PoAstV4 RNA was detected in low numbers (0.9–5.3 log₁₀ genomic copies/rectal swab) in rectal swabs from all of these pigs while all animals were negative for PoAstV1, PoAstV2, PoAstV3 and PoAstV5. At 19 and 20 days of age, high levels of PoAstV5 RNA (7.4–7.5 log₁₀ genomic copies/rectal swab) were detected in one pig, which had developed enteritis. At necropsy 1 day after the first evidence of PoAstV5 shedding, this pig was strongly positive for PoAstV5 RNA in most tissues with strong immunolabelling of PoAstV5 in enterocytes. Gene sequencing confirmed PoAstV5 infection. A retrospective investigation of PoAstVs 3, 4 and 5 in archival tissues from field cases of post-weaning enteritis identified high PoAstV4 or PoAstV5 antigen levels in intestinal tissues. These pigs were often concurrently infected with porcine rotavirus. Our findings suggest that PoAstV5 may contribute to the pathogenesis of enteritis in young pigs.

星状病毒 (AstVs) 是新兴的潜在人畜共患病原体，与各种动物物种的肠道和神经系统症状相关。在猪中，已鉴定出五个谱系，猪 AstVs (PoAstVs) 1$——$5. 我们现在报告一头缺乏初乳 (CD) 的猪与 PoAstV5 相关的萎缩性肠炎和田间肠炎病例中的类似疾病。将四只新生 CD 仔猪圈养在生物安全 2 级条件下，并监测直肠拭子和组织中 PoAstV RNA 的存在。在所有这些猪的直肠拭子中检测到低数量的 PoAstV4 RNA（0.9-5.3 log ₁₀基因组拷贝/直肠拭子），而所有动物的 PoAstV1、PoAstV2、PoAstV3 和 PoAstV5 均为阴性。在 19 和 20 日龄时，高水平的 PoAstV5 RNA（7.4–7.5 log ₁₀在一只患肠炎的猪身上检测到基因组拷贝/直肠拭子）。在 PoAstV5 脱落的第一个证据后 1 天的尸检中，这头猪在大多数组织中呈强阳性的 PoAstV5 RNA，肠细胞中 PoAstV5 具有强免疫标记。基因测序证实了 PoAstV5 感染。对来自断奶后肠炎现场病例的档案组织中的 PoAstV 3、4 和 5 进行回顾性研究，发现肠道组织中的 PoAstV4 或 PoAstV5 抗原水平较高。这些猪经常同时感染猪轮状病毒。我们的研究结果表明 PoAstV5 可能有助于幼猪肠炎的发病机制。