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Chapter 1
S. Agona has also been implicated in two large consecutive outbreaks
associated with contaminated powdered infant milk formula produced in
France. The outbreaks which were traced back to a contaminated
production line [50]. These outbreaks were responsible for a total of 141
confirmed cases in infants less than 12 months of age. The outbreaks were
identified by the public health department due to a sudden increase in
reported cases of S. Agona from January to February 2005, in comparison
to the usual low incidence of S. Agona cases reported [50]. In a similar
situation in Germany, the authorities noticed an increase in the number of
cases of S. Agona over a two month period of January to February 2003,
the reported cases were almost entirely in infants less than 13 months of
age. Through an epidemiological investigation, S. Agona was traced back to
12 aniseed containing herbal teas that had been imported from Turkey. It
was suspected that the aniseeds may have been contaminated by the use
of manure as a fertilization agent [51]. A total of 40 cases of S. Agona were
linked to the contaminated aniseed (through PFGE profile).
The largest S. Agona outbreak reported in the US was due to contaminated
“Malt-o-meal” toasted oat cereal, which involved over 200 cases in 11
American states [52]. An epidemiological study traced the contaminated
food back to the food processing plant where an extensive environmental
study was performed. S. Agona was found in low levels throughout the
plant including the floor, production equipment and the exhaust system in
the plant [34, 53]. In addition to the contaminated surfaces, the health
authorities also found that the insanitary condition of equipment, poor
staff preparation practices, and an incorrect water supply system were
factors which could have lead to the outbreak [54]. Subsequent to the S.
Agona outbreak in “Malt-o-Meal” cereal in 1998, there was an additional
outbreak 10 years later, with an unsweetened puffed rice and wheat cereal.
After prompt identification, notification to the authorities and product
recall this outbreak was notably smaller than the first, with a total of 28
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