Distribution and risk factors of bovine cysticercosis in Belgian dairy and mixed herds.

Bovine cysticercosis is an important food safety issue that is of economic concern. In Belgium, in the last years an increase in the number of cases, mostly light infections, was observed. The role of contact with contaminated surface water has been hypothesized as the main route of transmission. Based on abattoir records from 2001 till 2003 the distribution and risk factors of bovine cysticercosis among dairy and mixed farms were studied in four provinces, using Geographic Information Systems (GIS) and questionnaires. The risk factors were analysed using a case-control study design. The case group consisted of herds from which homebred cattle with cysticercosis had been detected at the abattoir; the control group was composed of herds where no cases had been detected. Case herds were distributed over the study area. A logistic regression analysis revealed that the location (province), the number of slaughtered cattle, the flooding of pastures, free access of cattle to surface water and the proximity of wastewater effluent were significant explanatory variables for bovine cysticercosis to be recorded in a herd.

First isolation of Trichinella britovi from a wild boar (Sus scrofa) in Belgium.

Since 1992, when the European Union Council Directive requires that wild boars (Sus scrofa) hunted in EU for commercial purpose should be examined for Trichinella, the infection has not been detected in wild boars from Belgium, despite serological evidence of the presence of anti-Trichinella antibodies in wildlife and previous reports of Trichinella larvae in this host species. In November 2004, Trichinella larvae were detected in a wild boar hunted near Mettet, Namur province (Southern Belgium). Larvae were identified as Trichinella britovi by polymerase chain reaction methods. This is the first report of the identification of Trichinella larvae from Belgium at the species level. The detection of T. britovi in wildlife in Belgium is consistent with findings of this parasite in other European countries and confirms the need to test game meat for Trichinella to prevent its transmission to humans.

Survey on porcine trichinellosis in Ecuador.

A survey on porcine trichinellosis was organised in Ecuador between 2000 and 2003. Blood samples were taken in slaughterhouses (study 1, n=2000; study 2, n=331) and in a remote village where pigs are free roaming (study 3, n=646) and examined by ELISA using excretory/secretory (E/S) antigens. Seven samples (0.35%) in study 1 and none of the samples of study 2 were serologically positive. Thirty-seven (5.72%) village pigs tested positive by E/S ELISA in study 3. Sero-positive results by the E/S ELISA in study 1 were confirmed by ELISA using beta-tyvelose antigen, and by immunoblot. Muscle samples taken from pigs slaughtered in the abattoir (study 2) and from animals that showed a positive serology in study 3 were examined by trichinoscopy and artificial digestion. These techniques failed to demonstrate the presence of muscle larvae. The results of this survey need confirmation, but suggest that Trichinella is present in Ecuador; however, prevalence and parasite burdens are likely to be very low. The likelihood of detecting trichinellosis are higher in traditional settings than in pigs raised on improved farms.

Trichinellosis: old facts and new developments.

Trichinellosis is a helminth zoonosis, which is known since long, but which is emerging or re-emerging in several regions of the world. During the last years the number of cases of trichinellosis in pigs and man in several East-European countries has increased very much due to the breakdown of the veterinary services because of the difficult political and socio-economic situation. In several third world countries on the other hand trichinellosis has become more important due to the increasing number of small traditional pig farms, in which the hygienic conditions are suboptimal. Furthermore, outbreaks of human trichinellosis have been reported due to recently discovered new species such as T. pseudospiralis and T. papuae. Over the last 25 years horsemeat has been more important as a source of human trichinellosis within the European Union than pork or wild boar meat. In Belgium, however, no cases of human trichinellosis have been reported since 1979. A review is presented of the available data on animal trichinellosis in Belgium. The potential risk for the consumer is discussed. Finally, some suggestions are made for a new approach of trichinellosis control in Belgium and the European Union.

Collaborative study on the use of motility enrichment on modified semisolid Rappaport-Vassiliadis medium for the detection of Salmonella from foods.

A collaborative study was performed in 15 laboratories to evaluate the use of motility enrichment on modified semisolid Rappaport-Vassiliadis (MSRV) medium for rapid Salmonella detection in a variety of food products. The results of this procedure were compared with those obtained by the cultural procedure using Rappaport-Vassiliadis (RV) broth as selective enrichment and modified brilliant green agar for selective plating. The tests were performed with Salmonella reference samples (SRS) as well as with naturally contaminated food products. When SRS were used without added food the productivity of both MSRV and RV was 96%. When SRS were combined with reference samples containing competitive bacteria the productivity was 98% for MSRV and 95% for RV. In the tests with food samples the productivity of MSRV was 92% with SRS added to food and 96% with naturally contaminated samples, while the productivity of RV was 88% and 90%, respectively. Statistical analysis showed that there was no significant difference between the procedures.

Characterization of a Trichinella isolate from polar bear.

An isolate of Trichinella of polar bear origin was studied by isoenzymatic typing. It was found referable to Trichinella nativa. While the Wistar rats proved nearly refractory to this isolate, the Swiss albino mice were highly susceptible. Ninety-one per cent of the cystic lesions in the diaphragm of the polar bear contained viable larvae after over 20 years of acquisition of the infection by the host which is a case of extreme adaptability of the parasite to its host. The anatomo-pathological aspects of these lesions are studied and the zoonotic significance of this isolate examined.