RESUMO
Foodborne illnesses investigated in the period 1991 to 1994 by the regional Food Inspection Services in The Netherlands are summarized and evaluated. In this period 2,621 incidents were reported, involving 7,567 ill people. Types of food most commonly implicated were Chinese-Indonesian food and meat products. More than half of the incidents were reported to originate in a restaurant or snack bar. Although laboratory investigations were carried out when possible, a likely causative agent was identified in only 8.3% of the incidents. Of the incidents with a known etiological agent, 19% were attributed to Bacillus cereus , 16% to Salmonella spp., 11% to Clostridium perfringens , 10% to chemical toxins, 6% to Escherichia coli , and 5% to Staphylococcus aureus . The present system covers only a tiny proportion of all foodborne illness and does not utilize epidemiological evidence to identify the source of outbreaks. It is recommended to supplement the microbiological data collected at present with epidemiological evidence, in particular in outbreaks involving 10 people or more.
RESUMO
A double-blind experiment with 34 healthy human volunteers, aged between 20 and 60 years, was conducted to obtain information about the allowable concentration of B. cereus in pasteurized milk. During a period of 3 weeks the subjects were exposed to B. cereus naturally present in pasteurized milk following storage for 3 to 14 days at 7.5°C. Of 259 milk exposures, gastrointestinal complaints were observed in 18 cases. According to total numbers of B. cereus ingested per exposure the complaints per number of exposures were distributed as follows: < 106: 5 in 132; 106 to 107: 2 in 32; 107 to 108 : 2 in 26; and > 108: 9 in 69. Symptoms, however, were not typical of those caused by B. cereus . There was a weak significance (P ≤ 0.1) for symptoms when > 108 B. cereus cells were ingested. Milk with 106 to 107 B. cereus cells per ml showed a very low diarrheal enterotoxin titer. Pure cultures of B. cereus strains isolated from samples with high B. cereus concentrations also showed a low production of enterotoxin. It can be concluded that for healthy adults the probability of become diseased from cold-stored pasteurized milk is small. From the results no evidence is obtained that B. cereus concentrations less than 105/ml will cause intoxication.
RESUMO
In 1991 and 1993 cereals were sampled during harvest in The Netherlands. The samples were tested for the presence of molds and the samples of 1993 were additionally tested for the mycotoxins deoxynivalenol and zearalenone. The molds were identified to genus level and those belonging to the genus Fusarium to species level. The total fungal infection of cereals in 1991 did not differ from 1993, with a median value of 5.0 log CFU g-1 in both years. The incidences of the genera Aspergillus , Penicillium , the group of Mucor and Rhizopus , Cladosporium , and Fusarium differed considerably between the two years, possibly caused by the different weather conditions. The numbers of samples infected with Fusarium were much higher in 1993 (83%) than in 1991 (34%). In 1991, no Fusarium was detected in samples from the southern part of The Netherlands, as opposed to 1993, when Fusarium was found in all regions sampled. The most dominant Fusarium species in 1991 were Fusarium culmorum and Fusarium avenaceum . In 1993, Fusarium poae , Fusarium culmorum , and Fusarium crookwellense dominated. All these Fusarium species are known mycotoxin producers. Three percent of the cereal samples of 1993 contained deoxynivalenol and 1% contained zearalenone in levels of over 500 µg kg-1 and 200 µg kg-1, respectively. This study has shown that the incidences of various fungal genera and Fusarium species in cereals in The Netherlands can vary from year to year. Considerable numbers of toxigenic Fusarium molds can occur and Fusarium mycotoxins may be present.
