Bivalve molluscan shellfish like clams and oysters, etc., are capable to bioaccumulate surrounding contaminants from waters into their digestive systems and posing serious threats of food poisoning. Detection of rotaviruses (RVs) in shellfish is of particular importance because RVs are prone to genome reassortment resulting in the emergence of new RV variants that may compromise vaccine safety. Herein, we have detected the wild-type RVs and Rotarix/RotaTeq vaccine strains in freshwater clams collected on the riverside, Kawasaki city, from July 2019 to January 2020 and correlated the detected genotypes with that of gastroenteritis cases of nearby clinics to understand the transmission of RVs in the environment. The wild-type RVs were detected in 62 (64.6%) out of 96 freshwater clams in every study month: July, September, November, and January that are considered as off-season for RV infections. The most frequent genotypes were G2 (42.9%), G8 (28.6%), G3 (14.3%), G1 (7.1%), and G10 (7.1%), which remained comparable with genotypic distribution found in the clinical samples over the last few years indicating that these RVs may accumulate in clams since a long time. However, G10 genotype was detected in clam but not in clinical samples suggesting the presence of asymptomatic infection or RVs could be carried out from a long distance. Importantly, vaccine strains, RotaTeq (1%) but not Rotarix (0%), were also detected in a clam. Attention must be paid to monitoring the potential transmission of wild-type and vaccine RV strains in the environment to prevent the emergence of new variants generated from genome reassortment with vaccine strains.

双壳贝类，如蛤蜊和牡蛎等，能够将周围的污染物从水中生物积累到它们的消化系统中，并构成食物中毒的严重威胁。检测贝类中的轮状病毒 (RVs) 尤为重要，因为 RVs 容易发生基因组重组，从而导致出现可能危及疫苗安全性的新 RV 变体。在此，我们检测了 2019 年 7 月至 2020 年 1 月在川崎市河边采集的淡水蛤蜊中的野生型 RVs 和 Rotarix/RotaTeq 疫苗株，并将检测到的基因型与附近诊所的胃肠炎病例的基因型相关联，以了解传播情况环境中的房车。在每个研究月的 96 只淡水蛤中，有 62 只（64.6%）检测到野生型 RV：7 月、9 月、11 月、和 1 月被认为是 RV 感染的淡季。最常见的基因型是 G2 (42.9%)、G8 (28.6%)、G3 (14.3%)、G1 (7.1%) 和 G10 (7.1%)，与过去在临床样本中发现的基因型分布保持可比性几年表明这些房车可能会在很长一段时间内积累在蛤蜊中。然而，在蛤蜊中检测到 G10 基因型，但在临床样本中未检测到，这表明可以从远距离进行无症状感染或 RVs 的存在。重要的是，在蛤蜊中也检测到疫苗株RotaTeq (1%)，而不是Rotarix (0%)。必须注意监测野生型和疫苗 RV 毒株在环境中的潜在传播，以防止出现由疫苗毒株基因组重排产生的新变体。