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Hepatitis 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.


To 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.


The 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.


Most 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.


This 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.


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  1. World Health Organization (WHO). Hepatitis A. Geneva: WHO. [Accessed: 27 Jul 2020]. Available from: https://www.who.int/news-room/fact-sheets/detail/hepatitis-a
  2. World Health Organization (WHO). Global Hepatitis Report 2017. Geneva: WHO; 2017. Available from: https://www.who.int/publications/i/item/global-hepatitis-report-2017
  3. Costa-Mattioli M, Cristina J, Romero H, Perez-Bercof R, Casane D, Colina R, et al. Molecular evolution of hepatitis A virus: a new classification based on the complete VP1 protein. J Virol. 2002;76(18):9516-25.  https://doi.org/10.1128/JVI.76.18.9516-9525.2002  PMID: 12186933 
  4. Syed NA, Hearing SD, Shaw IS, Probert CS, Brooklyn TN, Caul EO, et al. Outbreak of hepatitis A in the injecting drug user and homeless populations in Bristol: control by a targeted vaccination programme and possible parenteral transmission. Eur J Gastroenterol Hepatol. 2003;15(8):901-6.  https://doi.org/10.1097/00042737-200308000-00011  PMID: 12867801 
  5. Latvijas Vēstnesis. Epidemioloģiskās drošības likums. [Epidemiological Safety Act]. Riga: Saeima; 11 Dec 1997. Latvian. Available from: https://likumi.lv/ta/id/52951-epidemiologiskas-drosibas-likums
  6. Bruni R, Taffon S, Equestre M, Chionne P, Madonna E, Rizzo C, et al. . Key role of sequencing to trace hepatitis a viruses circulating in Italy during a large multi-country European foodborne outbreak in 2013. PLoS One. 2016;11(2):e0149642.  https://doi.org/10.1371/journal.pone.0149642  PMID: 26901877 
  7. Holmberg SD. Hepatitis a epidemiology goes global. Clin Infect Dis. 2012;54(6):782-3.  https://doi.org/10.1093/cid/cir945  PMID: 22238164 
  8. Robertson BH, Jansen RW, Khanna B, Totsuka A, Nainan OV, Siegl G, et al. Genetic relatedness of hepatitis A virus strains recovered from different geographical regions. J Gen Virol. 1992;73(6):1365-77.  https://doi.org/10.1099/0022-1317-73-6-1365  PMID: 1318940 
  9. Ching KZ, Nakano T, Chapman LE, Demby A, Robertson BH. Genetic characterization of wild-type genotype VII hepatitis A virus. J Gen Virol. 2002;83(1):53-60.  https://doi.org/10.1099/0022-1317-83-1-53  PMID: 11752700 
  10. Probst C, Jecht M, Gauss-Müller V. Intrinsic signals for the assembly of hepatitis A virus particles. Role of structural proteins VP4 and 2A. J Biol Chem. 1999;274(8):4527-31.  https://doi.org/10.1074/jbc.274.8.4527  PMID: 9988685 
  11. European Commission (EC). Commission Implementing Decision (EU) 2018/945 of 22 June 2018 on the communicable diseases and related special health issues to be covered by epidemiological surveillance as well as relevant case definitions C/2018/3868. Official Journal of the European Union. 6.7.2018. L 170/1. Available from: http://data.europa.eu/eli/dec_impl/2018/945/oj
  12. Centre for Disease Prevention and Control (CDC) of Latvia. Epidemiological bulletin of Infectious diseases in Latvia 2017. Riga: CDC of Latvia; 20.02.2018;8(1559). Latvian. Available from: https://www.spkc.gov.lv/sites/spkc/files/pielikumi/12_17.pdf
  13. Centre for Disease Prevention and Control (CDC) of Latvia. Epidemiological bulletin of Infectious diseases in Latvia 2018. Riga: CDC of Latvia; 08.03.2019;Nr.11(1615). Latvian. Available from: https://www.spkc.gov.lv/sites/spkc/files/pielikumi/12_18.pdf
  14. Centre for Disease Prevention and Control (CDC) of Latvia. Epidemiological bulletin of Infectious diseases in Latvia 2019. Riga: CDC of Latvia; 22.03.2021;13(1723). Latvian. Available from: https://www.spkc.gov.lv/lv/epidemiologijas-bileteni
  15. National Institute for Public Health and the Environment (RIVM). HAVNET. Bilthoven: RIVM. [Accessed 16 Dec 2019]. Available from: https://www.rivm.nl/en/havnet
  16. Tamura K, Stecher G, Peterson D, Filipski A, Kumar S. MEGA6: molecular evolutionary genetics analysis version 6.0. Mol Biol Evol. 2013;30(12):2725-9.  https://doi.org/10.1093/molbev/mst197  PMID: 24132122 
  17. World Medical Association (WMA). WMA Declaration of Helsinki– ethical principles for medical research involving human subjects. Ferney-Voltaire: WMA; 2018. Available from: https://www.wma.net/policies-post/wma-declaration-of-helsinki-ethical-principles-for-medical-research-involving-human-subjects/
  18. European Centre for Disease Prevention and Control (ECDC). ECDC Surveillance Atlas of Infectious Diseases, 2017-2019. Stockholm: ECDC. [Accessed: 10 Nov 2020]. Available from: https://atlas.ecdc.europa.eu/public/index.aspx
  19. Perevoščikovs J, Lucenko I, Magone S, Brila A, Curikova J, Vennema H. Community-wide outbreak of hepatitis A in Latvia in 2008 - an update. Euro Surveill. 2009;14(3):19092.  https://doi.org/10.2807/ese.14.03.19092-en  PMID: 19161728 
  20. European Centre for Disease Prevention and Control (ECDC). Epidemiological update: Hepatitis A outbreak in the EU/EEA mostly affecting men who have sex with men. Stockholm: ECDC; 12 Sep 2018. Available from: https://www.ecdc.europa.eu/en/news-events/epidemiological-update-hepatitis-outbreak-eueea-mostly-affecting-men-who-have-sex-men-2
  21. Ndumbi P, Freidl GS, Williams CJ, Mårdh O, Varela C, Avellón A, et al. Hepatitis A outbreak disproportionately affecting men who have sex with men (MSM) in the European Union and European Economic Area, June 2016 to May 2017. Euro Surveill. 2018;23(33).  https://doi.org/10.2807/1560-7917.ES.2018.23.33.1700641  PMID: 30131095 
  22. Gozlan Y, Bar-Or I, Rakovsky A, Savion M, Amitai Z, Sheffer R, et al. Ongoing hepatitis A among men who have sex with men (MSM) linked to outbreaks in Europe in Tel Aviv area, Israel, December 2016 - June 2017. Euro Surveill. 2017;22(29):30575.  https://doi.org/10.2807/1560-7917.ES.2017.22.29.30575  PMID: 28749336 
  23. Beauté J, Westrell T, Schmid D, Müller L, Epstein J, Kontio M, et al. Travel associated hepatitis A in Europe, 2009 to 2015. Euro Surveill. 2018;23(22).  https://doi.org/10.2807/1560-7917.ES.2018.23.22.1700583  PMID: 29871720 
  24. European Centre for Disease Prevention and Control (ECDC). Technical meeting on hepatitis A outbreak response. Stockholm: ECDC; 3 Apr 2009. Available from: https://www.ecdc.europa.eu/en/publications-data/technical-meeting-hepatitis-outbreak-response
  25. Nainan OV, Xia G, Vaughan G, Margolis HS. Diagnosis of hepatitis a virus infection: a molecular approach. Clin Microbiol Rev. 2006;19(1):63-79.  https://doi.org/10.1128/CMR.19.1.63-79.2006  PMID: 16418523 

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