The occurrence of salmonellae in kitchens of care institutions.

Sporadic cases of salmonellosis always by the same serotypes occurred in two different care institutions. In the first institution the cases had been caused by S. binza and S. eimsbuettel, in the second by S. mons and S. braenderup. The cases of salmonellosis prompted studies into the occurrence of these Salmonella serotypes in the kitchens of the relevant institutions, as well as into the occurrence of salmonellas in kitchens of care institutions in general. Using Moore's swabs the relevant Salmonella serotypes could be demonstrated in the kitchens of the institutions with sporadic cases of salmonellosis, while in kitchens of 15 other arbitrary chosen institutions Salmonella could not be detected at all. This demonstrated that the occurrence of sporadic cases of salmonellosis was related to the occurrence of salmonellas in the kitchens. Then investigations were started to establish the origin of the salmonellas. There was a mice plague in one institution. Mouse-dung was found positive for the relevant Salmonella serotype(s). Cases of salmonellas did not occur any more when the mice had been eradicated. It was concluded that the sporadic cases of salmonellosis in that institution were strongly associated with the presence of mice. In the other institution it appeared that disinfection was inadequate and that salmonellae were spread all over the kitchen environment during cleaning, leading to recontamination. After thorough disinfection and adaptation of cleaning and disinfection procedures sporadic cases of salmonellosis did not occur anymore. Results of these investigations demonstrated the important role of vermin and proper cleaning and disinfection in food hygiene. Moreover, the sporadic cases of salmonellosis came to light because gastro-enteritis was a reason for examination of faecal specimens of patients. This is not usual in many care institutions. However, in this way problems in hygiene can be traced, especially in the kitchen. For this reason it is recommended strongly to examine faecal specimens in cases of gastro-enteritis, even in sporadic cases.