Listeria-encefalitis in cows through litter from a broiler-farm.

In a loose-housed herd four cows are emergency-slaughtered, within some weeks, because of symptoms of encefalitis. From the brains of these cows, as well as from the litter, coming from broilers, that had been put in the cow-stables before, Listeria monocytogenes type 4b has been isolated. At the same time an investigation was made from faeces/intestinal contents of broilers. Out of the contents of 2.373 intestines, 1% of about 2.300.000 broilers ready for use, coming from 146 farms, 4.1% L.monocytogenes has been isolated. Six broiler farms are infected, at two farms it occurred even for the second time. Three times it concerned L.monocytogenes type 4b, two times type 1 and one strain could not be serotyped.