BfR
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Annual Report 2014
44
Clarification of an EU-wide outbreak
of hepatitis A
The BfR has a high level of expertise in the area of tracing
food chains. The Institute developed the free “FoodChain-
Lab” software for the visualisation and analysis of large
volumes of delivery data (see BfR Annual Report 2013).
In November 2013, the EFSA therefore appointed a work-
group at the BfR for the clarification of a Europe-wide out-
break of Hepatitis A (HAV). At the time, a large number
of cases of HAV had occurred in Italy, Ireland and the
Netherlands. A total of more than 1,400 people in dif-
ferent European countries had contracted hepatitis A,
and the strain KF182323 was confirmed in 331 of these
cases. Frozen berries were quickly
identified as the vehicle of infection
for this outbreak. However, the types
of berries, the harvest year, and the
country or region in which the out-
break originated were still unclear.
To analyse the circumstances of the outbreak, the af-
fected countries collected traceability data for all berries
suspected of being contaminated and sent this data via
the European Commission to the EFSA as a central eval-
uation body. The BfR subsequently collated all the data in
FoodChain-Lab, checked it for plausibility, and subjected
it to an in-depth analysis. During several meetings at the
BfR, the members of the EFSA workgroup then simulated
various contamination scenarios and decided on further
steps for tracing products.
The “HAV Trace” workgroup, which was made up of rep-
resentatives not only of the BfR but also of the affected
countries (Italy, the Netherlands, Ireland, France, Norway
and Poland) and of the EFSA, the European Commis-
sion and the European Centre for Disease Prevention
and Control, came to the conclusion that the most likely
sources of the outbreak were redcurrants from a specific
region in Poland or blackberries from Bulgaria.
Carbapenem resistentance in bacteria
from livestock
Resistance to antibiotics is relevant to consumer health
protection, particularly when it leads to restrictions in
treating infections in humans. Research on mechanisms
and factors responsible for transferring resistant bacte-
ria from animals to humans through food is therefore of
special importance. Generally speaking, antibiotic-re-
sistant bacteria are not more pathogenic in humans than
bacteria without this property. However, some of these
resistant bacteria can transfer their resistance genes to
other pathogens or to the bacteria in the human micro-
flora. When resistant bacteria cause an illness, such as
a wound infection or blood poisoning, they may be more
difficult to treat.
The BfR investigates the distribution of resistance to
carbapenems, inter alia. Carbapenems are a class of
substances which are used among other things to treat
infections with multi-drug-resistant
Enterobacteriaceae
which are no longer affected by important antibiotics
such as cephalosporins. One mechanism leading to re-
sistance of bacteria to carbapenems is the formation of
specific enzymes known as carbapenemases. Because
bacteria can pass on resistance to carbapenems to oth-
er bacteria species, consumers could theoretically take
in bacteria with this resistance property through food or
through direct contact with animals. In human medicine,
an increase of carbapenemase-forming
Enterobacte-
riaceae
and other gram-negative bacteria has been ob-
served in Germany in recent years.
During studies within the scope of the research project
RESET, which investigates the prevalence of cepha-
losporin-resistant bacteria in animals and food, the
BfR confirmed the presence of bacteria with carba-
penemases in livestock for the first time in 2011. These
were Salmonella isolates from three herds of fattening
pigs and one flock of broilers. These resistance proper-
ties were also detected in non-pathogenic (commensal)
E. coli
from one of the herds of fattening pigs. A gene
for the formation of the carbapenemase VIM-1 enzyme
was identified in these bacteria through molecular bio-
logical analyses. It is not clear how the resistance genes
or modified genes entered the livestock and their envi-
ronment. Entry through live vectors such as people, wild
animals, rodents or livestock or through non-living agents
such as feed, water or air is conceivable. Since 2014,
more intense checks have been in place EU-wide for the
presence of isolates with carbapenem-resistance. It is
encouraging that no isolates examined in zoonosis moni-
toring have been confirmed as capable of forming car-
bapenemase in Germany since this time.
