More than 40 cases of Hepatitis A have been reported in six European Union countries, according to the European Center for Disease Prevention and Control (ECDPC).
The 42 cases across Denmark, France, Germany, the Netherlands, Spain and the United Kingdom are infected with one of two distinct Hepatitis A virus genotype IA strains. The cases are classified as either autochthonous, i.e. infected in the EU, or as travel-related, i.e. with a travel history to Morocco.
Although the source of infection is unknown, EU autochthonous cases are likely to have been infected through foodborne or, the ECDPC says. 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. Person-to-person transmission routes are also being investigated.
Historically, both strains have been found to be epidemiologically associated with Morocco. However, many of the 2018 cases do not have a travel history to Morocco. Cases were identified through sequencing of a viral RNA fragment in the overlapping region.
Based on recent and historical molecular findings in travelers returning from Morocco and in a resident in Morocco, it is most likely that these strains have been circulating in Morocco since at least 2011, and that transmission in Morocco has been ongoing until very recently.
Hepatitis A is a liver infection that can be prevented with a vaccine and can be serious for some people. It is highly contagious, and symptoms include, fever, nausea, fatigue, jaundice, dark urine, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay-colored stools, joint pain, and jaundice.
The two outbreak strains in the recently identified outbreak are not related to strains associated with an ongoing outbreak that began in 2016 in the EU and is disproportionally affecting men who have sex with men. The strain in the new outbreak also is not the same as was responsible for two foodborne outbreaks in EU countries in 2012-14. Those two outbreaks were associated with consumption of frozen strawberries and frozen mixed berries.
Epidemiological investigations are 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.
Raising awareness among clinicians about the need for early detection and reporting is likely to help ongoing epidemiological investigations as well as reduce the risk of secondary transmission.