Estimating the probability of freedom of classical swine fever virus of the East-Belgium wild-boar population.

A report of the Scientific Committee on Animal Health and Animal Welfare of the European Commission (CEC, 1999.) includes recommendations for setting up monitoring programmes for classical swine fever (CSF) infection in a wild-boar population, based on the assumption that one would detect at least 5% prevalence in a CSF-infected wild-boar population. This assumption, however, is not science based. We propose an alternative method to provide evidence for a wild-boar population being free of CSF and evaluate the efficiency of a surveillance programme that was implemented in Belgium in 1998. In our study, the probability of freedom of CSF-virus was estimated based on 789 samples; these were collected from wild-boars within the surveillance programme (within the three provinces which include 95% of the Belgian wild-boar population) and examined by three diagnostics methods (antibody detection, virus detection and virus RNA detection). A Bayesian framework was used for the estimation, accounting for the diagnostic test characteristics without the assumption of the presence of a gold standard. The median probability of freedom of CSF-virus was estimated at 0.970, with a 95% credibility interval of 0.149-1.000. Independent on the choice of the prior information, the posterior distributions for the probability of freedom of CSF-virus were always skewed close to the upper boundary of 1. This represents a big gain of knowledge since we did not use any prior information for the probability of freedom of CSF-virus and took the uncertainty about the accuracy of the diagnostic methods into account.

Prevalence of bovine herpesvirus-1 in the Belgian cattle population.

The national bovine herpesvirus 1 (BHV-1) seroprevalence (apparent prevalence) in the Belgian cattle population was determined by a serological survey that was conducted from December 1997 to March 1998. In a random sample of herds (N=556), all cattle (N=28478) were tested for the presence of antibodies to glycoprotein B of BHV-1. No differentiation could be made between vaccinated and infected animals, because the exclusive use of marker vaccines was imposed by law only in 1997 by the Belgian Veterinary Authorities. Twenty-one percent of the farmers vaccinated continuously against BHV-1. In the unvaccinated group, the overall herd, individual-animal and median within-herd seroprevalences were estimated to be 67% (95% confidence interval (CI)=62-72), 35.9% (95% CI=35.0-36.8) and 33% (quartiles=14-62), respectively. Assuming a test sensitivity and specificity of 99 and 99.7%, respectively, the true herd, individual-animal and median within-herd prevalence for the unvaccinated group of herds were estimated to be 65, 36 and 34%, respectively. The true herd prevalence for dairy, mixed and beef herds were respectively, 84, 89 and 53%; the true individual-animal prevalence for those types of herds were, respectively, 35, 43 and 31%; whereas, the true median within-herd prevalences were 36, 29 and 38%.

[In vitro study of the adsorption of chloroquine by an antidiarrheal remedy traditionally used in Africa]. / Etude in vitro de l'adsorption de la chloroquine par un remède antidiarrhéique employé traditionnellement en Afrique.

Mouboumou is a traditional medicine prepared from the inner part of termitarium and is used in traditional medicine in Zaire. In tropical diseases, antimalarial drugs are often used simultaneously with antidiarrheal absorbent drugs, which might, by their adsorbent properties, compromise the efficacy of the antimalarial treatment. The present in vitro study has allowed to determine the adsorption characteristics of chloroquine on Mouboumou; kaopectate was used a reference adsorbent. The adsorption of chloroquine by these two adsorbents is very important (from 30 to 60%) and fits quite well in with the Langmuir's relation. A decrease of bioavailability of chloroquine, due to the adsorption phenomena, might be observed in vivo and could contraindicate the concomitant administration of these drugs.

Monitoring of the intra-dermal tuberculosis skin test performed by Belgian field practitioners.

The present study aimed to monitor skin test practices as performed by veterinarian field practitioners in Belgium. For this purpose, an anonymous postal questionnaire was elaborated and dispatched to veterinarians involved in bovine tuberculosis detection. The questionnaire included items focusing on the skin test performance. International experts in the field of bovine tuberculosis were asked to fill the questionnaire and a scoring scale was built as follows: 0 = 'ideal' answer, 1 = acceptable answer, whereas 2 = unacceptable answer. Furthermore, experts were asked to rank the questionnaire's items according to their possible impact on the risk of not detecting reactors. A global score was further calculated for each participant and a comparison of practices was carried out between the two regions of the country, i.e. Wallonia and Flanders. Significant differences were observed between both regions, a harmonization at the country level is thus essential. No veterinarian summed a null score, corresponding to the ideal skin test procedure, which suggests that skin-testing is far from being performed correctly. Field practitioners need to be sensitized to the importance of correctly performing the test. The authors recommend the questionnaire is suitable for application in other countries or regions.

[Pharmacology and psychotherapy in general practice]. / Pharmacologie et psychothérapie de l'omnipraticien.

The G. P. is confronted with any kind of illness, with or without a specific label. Most important is the quality of his relationship with the patient, without neglecting a very good theoretical and practical knowledge. Confronted with functional disorders, evident or marked depression, he will usually not have sufficient training for a real psychotherapy. He must acquire a good knowledge of psychopharmacology without being carried away with publicity stunts. Post graduate training of the Balint type is indicated, to get acquainted with the emotional reactions of his patients, to be able to cope with them and at the same time learn to know himself.

Model for the electrolytic environment and electrostatic properties of biomembranes.

Physical and chemical interactions of ions with biomembranes are described by a model originating from the Stern theory. Equations of the model have analytical solutions only for very simple, often unrealistic situations. The numerical resolution adopted permits a much wider application of the model: Potentials and concentrations can be calculated anywhere from the surface and in any electrolytic environment. The model is applied to biomembranes. Simulations are presented in three-dimensional figures which allow one to use the model as a practical research tool. In particular, the simulations reveal that, in practice, it is possible to induce an increase of the surface charge density simultaneously with a decrease of the surface potential, and, theoretically, that the potential at the exclusion distance (which estimates the diffuse layer thickness) exhibits a remarkably constant value as the composition of the free solution is varied.