An outbreak of genetically related hepatitis A virus (HAV) infections among people with no travel history was identified by the Public Health England (PHE) Virus Reference Department (VRD) in conjunction with local teams noting that the cases had eaten dates.
We describe investigations including case characteristics, phylogenetics, analytical studies, and control measures. We aim to flag the possible risk of hepatitis A to populations in other countries through the consumption of contaminated dates, particularly as Ramadan, which is associated with an increase in consumption of dates, began on 12 April 2021, and hepatitis A has a long incubation period of 15 to 50 days.
A confirmed case was defined as a laboratory-confirmed HAV infection with one of three clustered sequences (sequences VRD21_HAV005, VRD21_HAV009 and VRD21_HAV020) and onset date from 1 January 2021 in England or Wales, no travel history or contact with a suspected or confirmed HAV case in the 60 days before onset. A probable case was a laboratory-confirmed HAV infection, with no or pending sequencing result, and with an epidemiological link to a confirmed HAV case with one of the three clustered sequences.
Samples from all locally diagnosed HAV infections in England and Wales are routinely sent to the VRD for characterisation. The outbreak cases had HAV from three closely related Middle Eastern genotype IB sequences (≤ 2 bp different in a 505 bp segment) which clustered most closely with those found in travellers returning from Syria and Lebanon. The sequences have been submitted to the European Nucleotide Archive (ENA), accession numbers OD998295–OD998297.