Multi-country Hepatitis A outbreak potentially foodborne
Cases are infected with one of two hepatitis A virus (HAV) genotype IA strains historically epidemiologically associated with Morocco. However, most of the 2018 infections do not have a travel history to the country.
Denmark, France, Germany, the Netherlands, Spain and the UK are affected.
Autochthonous - infected in the EU - cases are likely to have been affected through foodborne or person-to-person transmission.
For the 42 confirmed infections, 39 were infected in the EU and three have travel history to Morocco. Thirteen people have been hospitalised but no deaths reported.
Single food item distributed in several countries
The European Centre for Disease Prevention and Control (ECDC) said although the source is unknown it is likely to be foodborne or via person-to-person transmission.
“The relative homogeneity of the viral strains associated with the outbreak cases suggests that foodborne transmission could be associated with a single food product that is distributed in several EU countries,” said the agency.
“Epidemiological investigations are currently ongoing in some of the affected EU countries to test several hypotheses. Considering that the source of the outbreak has not been definitively identified, there is a risk of further cases as part of this outbreak.”
ECDC said cases were identified through sequencing of a viral RNA fragment in the overlapping region VP1/P2A. HAV strains with 1-2 nucleotide differences in this RNA region are likely to be associated with a common origin.
Based on molecular findings in returning travellers from Morocco and in residents, it is likely these strains have been circulating in the country since at least 2011 and that transmission has been ongoing until recently.
No link to other Hepatitis A outbreaks
The two outbreak strains are not related to those associated with the 2016-18 outbreak in the EU that is affecting men who have sex with men (MSM) or with strains implicated in two foodborne outbreaks in 2012–14, which were linked to frozen strawberries and mixed berries.
Confirmed cases had a median age of 31 years (range: 17-48) and 19 were female.
Possible cases had a median age of 32 years (range: 23–49) and 27 were female.
Of the 46 cases where information is available 26 were hospitalised but no deaths reported.
In 2012-16, 30 EU countries noted between 12,500 and 14,100 confirmed cases of hepatitis A annually.
The most frequently reported countries of infection were Egypt (10%), Morocco (10%) and Turkey (8%).
Hepatitis A is a viral liver disease that can cause mild to severe illness but there is a vaccine to prevent it.
The incubation period is usually 14-28 days and symptoms can include fever, malaise, loss of appetite, diarrhoea, nausea, abdominal discomfort, dark-coloured urine and jaundice.