Riga East Clinical University Hospital, Infectology Centre of Latvia, National Microbiology Reference Laboratory, Riga, Latvia.
Euro Surveill. 2022 Mar;27(11). doi: 10.2807/1560-7917.ES.2022.27.11.2100415.
BackgroundHepatitis A is an acute infection of the liver caused by hepatitis A virus (HAV). Molecular detection and typing of the HAV VP1/P2A genomic region is used for genotyping and outbreak investigations. After a large hepatitis A outbreak in Latvia in 2007-08, only sporadic cases were registered until 2017 when a rise in cases occurred. During 2017-19, 179 laboratory-confirmed hepatitis A cases were notified in Latvia.AimTo investigate the observed increase in hepatitis A cases during 2017 and to determine whether these cases were linked to one another, to risk groups, or to other outbreaks. The majority of HAV samples (69.8%) were typed.MethodsThe VP1/P2A genomic region of HAV was amplified and sequenced for 125 case serum samples. Information about hepatitis-related symptoms, hospitalisation, vaccination, a possible source of infection and suspected countries of origin of the virus were analysed for sequenced cases.ResultsMost HAV strains were subgenotype IA (n = 77), of which 41 were strains circulating among men who have sex with men (MSM) populations in Europe (VRD_521_2016 (n = 32), RIVM-HAV16-090 (n = 7) or V16-25801 (n = 2)). Forty-four cases were subgenotype IB and four cases subgenotype IIIA. However, other clusters and sporadic cases were detected with or without identifying the epidemiological link.ConclusionThis work represents molecular epidemiological data of hepatitis A cases in Latvia from 2017 to 2019. Molecular typing methods allow identification of clusters for public health needs and establishing links with other outbreaks, and to compare Latvian strains with reported strains from other countries.
背景
甲型肝炎是由甲型肝炎病毒（HAV）引起的肝脏急性感染。HAV 的 VP1/P2A 基因组区域的分子检测和分型用于基因分型和暴发调查。在 2007-08 年拉脱维亚发生大规模甲型肝炎暴发后，直到 2017 年才登记到散发病例，此后病例数有所上升。2017-19 年，拉脱维亚报告了 179 例实验室确诊的甲型肝炎病例。
目的
调查 2017 年甲型肝炎病例的增加情况，并确定这些病例是否相互关联、与风险群体或其他暴发有关。大多数 HAV 样本（69.8%）进行了分型。
方法
对 125 例病例血清样本的 HAV VP1/P2A 基因组区域进行扩增和测序。对测序病例的肝炎相关症状、住院、疫苗接种、可能的感染源和疑似病毒来源国进行分析。
结果
大多数 HAV 株为亚基因组 IA 型（n=77），其中 41 株为欧洲男男性行为者（MSM）人群中流行的毒株（VRD_521_2016（n=32）、RIVM-HAV16-090（n=7）或 V16-25801（n=2））。44 例为亚基因组 IB 型，4 例为亚基因组 IIIA 型。然而，还检测到其他集群和散发病例，或未确定流行病学联系。
结论
本研究代表了 2017-2019 年拉脱维亚甲型肝炎病例的分子流行病学数据。分子分型方法可根据公共卫生需要识别集群，并与其他暴发建立联系，还可将拉脱维亚毒株与其他国家报告的毒株进行比较。
