[Epidemiological studies on salmonella in a particular area ("Walcheren Project"). III. The incidence of salmonella in man, insects, gulls as well as foods scrapings from butcher's blocks, effluents of sewage treatment plants and drains from butcher's shops (author's transl)].

In continuation of previous studies, various materials (meat and meat products, insects, gull droppings, scrapings from butcher's blocks, effluents of sewage treatment plants, drains from butcher's shops and faeces of patients) were examined again at the same time for the presence of Salmonella in a relatively small are (Walcheren) over a period of three months. As was also the case in previous studies, S. typhi murium (27.5 per cent), S. panama (22.2 per cent) and S. brandenburg (9.2 per cent) were the three serotypes most frequently isolated. The three most frequently isolated phage types of S. typhi murium were II 505 (62.1 per cent), II 502 (5.3 per cent) and I 650 (4.2 per cent). The serotypes and phage types were present in nearly all the materials studied which again emphasizes the fact that there are contamination cycles of Salmonella. These studies showed that the route of contamination divides in the butcher's shop. Salmonella ogranisms carried with the meat frome the slaughter-house find their way into the drains on the one hand, and, by meat and meat products, to consumers on the other. Moreover, the high degree of contamination of effluents is not in accordance with the small number of cases of salmonellosis.