G. Salvat et al., CONTROL OF LISTERIA-MONOCYTOGENES IN THE DELICATESSEN INDUSTRIES - THE LESSONS OF A LISTERIOSIS OUTBREAK IN FRANCE, International journal of food microbiology, 25(1), 1995, pp. 75-81
During a recent outbreak of foodborne listeriosis which occurred in Fr
ance in 1992, investigations were carried out in order to identify the
plants associated with the production of contaminated products. These
investigations were made in six 'suspect' delicatessen plants followi
ng the first epidemiological investigations, and in one 'control plant
'. The first visits were made during working operations. Two hundred a
nd seventy samples were taken ('environmental' swabs, air samples, pro
ducts), with 68% of the swabs being positive for Listeria monocytogene
s in raw product areas, and 33% positives in the finished product area
. The epidemic phagovar was identified in a single plant preparing por
k tongues in aspic.The major causes of contamination identified were c
ontact of cooked products with soiled surfaces, cross-contamination be
tween 'raw' and 'cooked' channels and the inadequacy of cleaning and d
isinfection procedures. A second visit was also made to five plants to
provide validation of their cleaning and disinfection procedures. Amo
ng 112 swabs collected, 17% of the samples from raw product surfaces a
nd 7% from finished product surfaces were found to be positive. These
results suggest that cleaning and disinfection procedures were unable
to eliminate sources of L. monocytogenes when not correctly applied.