16 Jul 2013

Hepatitis A - Multistate (Europe) - 2013 outbreak (ECDC/CDTR, July 16 2013, extracts)

[Source: European Centre for Disease Prevention and Control (ECDC), full PDF document: (LINK). Extract.]

COMMUNICABLE DISEASE THREATS REPORT

Week 28, 7-13 July 2013

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Hepatitis A - Multistate (Europe) - 2013 outbreak

Opening date: 9 April 2013 Latest update: 31 May 2013

 

Epidemiological summary

From 1 October 2012 until 11 July 2013, Denmark, Finland, Norway and Sweden reported 104 HAV cases due to genotype IB with two related sequences. None of the cases had travel history outside the EU within the period of their potential exposure.

Epidemiological investigations in Denmark and Sweden point towards frozen strawberries as the vehicle of infection.

On 22 May 2013, the Swedish Institute for Infectious Disease Control (SMI) published a press release indicating that frozen strawberries of non-domestic origin are likely to be the source of the Swedish outbreak. Other types of berries are no longer suspected in this outbreak.

On 30 May 2013, the Danish Food Safety Authority confirmed that specific products with frozen strawberries packaged in Belgium and sold in Denmark, have been voluntarily recalled. Both epidemiological and product investigations point towards these specific products of frozen strawberries as the vehicle of infection for the ongoing hepatitis outbreak in the Nordic countries.

Food authorities in the affected Nordic countries have recommended that citizens should boil frozen berries or berries of non-domestic origin before consumption.

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ECDC assessment

The identification of closely-related HAV sequences in four different countries confirms that this is a multinational food-borne outbreak. The source of the multi-country outbreak has not been confirmed, but epidemiological investigations in Denmark and Sweden point towards frozen strawberries as the vehicle of infection.

As control measures have been implemented in the four affected countries and the number of reported cases has declined, ECDC will close this event.

 

Actions

ECDC and EFSA published a joint rapid outbreak assessment on 16 April.

 

Hepatitis A -Multistate (Europe)- ex Italy

Opening date: 10 May 2013 Latest update: 17 June 2013

 

Epidemiological summary

Since 1 January 2013, 16 laboratory-confirmed cases of hepatitis A virus (HAV) infection have been reported in Germany, the Netherlands and Poland. All cases have a history of travel to the autonomous provinces of Trento and Bolzano in northern Italy during the exposure period. During the same period, Italy experienced an increase in cases of HAV infection, both in province of Trento and at national level. In the first six months of 2013, Italy reported more than 200 cases in excess of the mean number of cases reported in the same period for the last three years. This increase in cases is likely to be associated with this outbreak.

Additionally, Ireland reported three cases whose isolates share a sequence identical to that of the Italian outbreak, but without any history of travel to Italy or contact with other HAV cases. These cases had onset of illness in April 2013 in Ireland.

As the exposure of the cases occurred in Italy and Ireland, this suggests that cases have been exposed to the same contaminated vehicle of infection distributed in at least these two countries. Epidemiological, microbiological and environmental investigations indicate mixed frozen berries as the most likely vehicle of infection for these outbreaks.

In May 2013, following rapid alert system for food and feed (RASFF) notifications by Italian food authorities regarding HAV contamination found in a frozen berry mix originating in Italy, with raw berry material from Bulgaria, Canada, Poland and Serbia, the product was voluntarily withdrawn from the national market.

 

ECDC assessment

Despite the withdrawal of the incriminated food product, it is likely that additional cases will be identified and reported in Italy and, possibly, in Ireland, because of the long shelf-life of such frozen products. ECDC invites Member States to raise awareness of a possible increase in HAV cases associated with the Italian outbreak strain, to report all new cases in EPIS-FWD, to use the common epidemic case definition and questionnaire to interview recent cases and to sequence a subset of viral specimens in order to disclose possible links with the current outbreak in Italy.

 

Actions

A joint ECDC-EFSA assessment was published on this outbreak on 29 May 2013 and updated on 9 July.

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