Ongoing outbreak of hepatitis A associated with sexual transmission among men who have sex with men, Portugal, October 2023 to April 2024

Ebba Rosendal; Sebastian von Schreeb; Alexandre Gomes; Sara Lino; Berta Grau-Pujol; Sara Magalhães; Vasco Ricoca Peixoto; Carla Roque; Joana Moreno; Fernando Maltez; Fernando Almeida; Rita Sá Machado; Rui Tato Marinho; Paula Vasconcelos; Rita de Sousa; João Vieira Martins

Ongoing outbreak of hepatitis A associated with sexual transmission among men who have sex with men, Portugal, October 2023 to April 2024

Euro Surveill. 2024 May;29(21).

Authors

Ebba Rosendal^{1

2

3}, Sebastian von Schreeb^{1

4

5

6}, Alexandre Gomes⁷, Sara Lino⁸, Berta Grau-Pujol^{4

5

6}, Sara Magalhães⁸, Vasco Ricoca Peixoto⁵, Carla Roque², Joana Moreno⁴, Fernando Maltez⁸, Fernando Almeida⁹, Rita Sá Machado¹⁰, Rui Tato Marinho¹¹, Paula Vasconcelos⁵, Rita de Sousa^{12

2}, João Vieira Martins^{12

4}

Affiliations

¹ These authors contributed equally to this work and share first authorship.
² Infectious Diseases Department, National Institute of Health Doctor Ricardo Jorge, Lisbon, Portugal.
³ ECDC Fellowship Programme, Public Health Microbiology path (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
⁴ Directorate of Information and Analysis, Directorate-General of Health, Lisbon, Portugal.
⁵ Center for Public Health Emergencies, Directorate-General of Health, Lisbon, Portugal.
⁶ ECDC Fellowship Programme, Field Epidemiology path (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
⁷ National Programmes for Tuberculosis, Viral Hepatitis, STI and HIV, Directorate-General of Health, Lisbon, Portugal.
⁸ Infectious Diseases Department, Hospital de Curry Cabral; Unidade Local de Saúde de São José, Lisbon, Portugal.
⁹ National Institute of Health Doctor Ricardo Jorge, Lisbon, Portugal.
¹⁰ Directorate-General of Health, Lisbon, Portugal.
¹¹ Medical School of Lisbon, Universidade de Lisboa; Local Unit of Health Santa Maria; National Programme for Viral Hepatitis, Directorate-General of Health; Lisbon, Portugal.
¹² These authors contributed equally to this work and share last authorship.

PMID: 38785087

Abstract

An outbreak of hepatitis A is ongoing in Portugal, with 71 confirmed cases from 7 October 2023 to 24 April 2024. Most cases are male, aged 18-44 years, with many identifying as men who have sex with men (MSM) and reported as suspected sexual transmission. Phylogenetic analysis identified the subgenotype IA, VRD 521-2016 strain, last observed in an MSM-associated multi-country outbreak in 2016 to 2018. We wish to alert colleagues in other countries to investigate potential similar spread.

Keywords: Hepatitis A; Hepatitis A virus; MSM; Portugal; genotyping; outbreak; sexual transmission.

MeSH terms

Adolescent
Adult
Contact Tracing
Disease Outbreaks*
Female
Genotype*
Hepatitis A virus / classification
Hepatitis A virus / genetics
Hepatitis A virus / isolation & purification
Hepatitis A* / epidemiology
Hepatitis A* / transmission
Homosexuality, Male* / statistics & numerical data
Humans
Male
Middle Aged
Phylogeny*
Portugal / epidemiology
Sexual Behavior
Young Adult