Hepatitis A virus (HAV) is the major cause of enterically transmitted infectious hepatitis. Between 2016 and 2017, the number of confirmed cases of hepatitis A virus (HAV) increased from 64 to 786 in São Paulo affecting mainly adults aged between 18 and 39 years (80%) and males (88%). To support epidemiological surveillance, the present study monitored the presence of HAV in urban sewage samples collected bimonthly for 1 year (November 2017–November 2018) in the central region of the city, where most of cases were detected. Sewage samples were concentrated by polyethylene glycol precipitation and HAV RNA was quantified by RT-qPCR. Nucleotide sequencing targeting the VP1/2A junction region was carried out to genotype the HAV strains. HAV was detected in 76.9% (40/52) of the samples, with a geometric mean viral load of 5.09 × 10⁴ (± SD 4.51 × 10⁵) genome copies (GC/L) (Mauá Street) and 5.27 × 10⁴ (± SD 1.26 × 10⁶) GC/L (Prestes Maia Avenue). Of the 40 positive samples, 8 were typed as HAV subgenotype IA [100% nucleotide (nt) identity with HAV strain VRD_521_2016]. Highest homology was obtained with sequences from European countries (Italy, Spain) and Israel, all of which had reported recent HAV outbreaks associated with men who have sex with men. Our results highlight that wastewater surveillance is a useful tool to support investigating HAV outbreaks in the community, including circulating genotypes.

甲型肝炎病毒（HAV）是肠道传播的传染性肝炎的主要原因。2016 年至 2017 年期间，圣保罗的甲型肝炎病毒 (HAV) 确诊病例数从 64 例增加到 786 例，主要影响 18 至 39 岁的成年人 (80%) 和男性 (88%)。为支持流行病学监测，本研究监测了城市中部地区每双月采集的城市污水样本中 HAV 的存在情况，为期 1 年（2017 年 11 月至 2018 年 11 月），其中大部分病例被发现。污水样品通过聚乙二醇沉淀浓缩，HAV RNA 通过 RT-qPCR 定量。对 VP1/2A 连接区进行核苷酸测序以对 HAV 毒株进行基因分型。在 76.9% (40/52) 的样本中检测到 HAV，病毒载量的几何平均数为 5.09 × 10⁴ (± SD 4.51 × 10 ⁵ ) 基因组拷贝 (GC/L) (Mauá Street) 和 5.27 × 10 ⁴ (± SD 1.26 × 10 ⁶ ) GC/L (Prestes Maia Avenue)。在 40 个阳性样本中，8 个被分类为 HAV 亚基因型 IA [与 HAV 毒株 VRD_521_2016 100% 核苷酸 (nt) 同一性]。来自欧洲国家（意大利、西班牙）和以色列的序列获得了最高的同源性，所有这些国家都报告了最近与男男性行为相关的 HAV 暴发。我们的研究结果强调，废水监测是支持调查社区 HAV 爆发的有用工具，包括循环基因型。