Multicenter study of street foods in 13 towns on four continents by the food and environmental hygiene study group of the international network of pasteur and associated institutes.

An international multicenter study of ready-to-eat foods, sandwiches, and ice creams or sorbets sold in the streets and their vendors was carried out to assess the microbiological quality of these foods and to identify characteristics of the vendors possibly associated with pathogens. Thirteen towns in Africa, America, Asia, and Oceania were involved in the study. A single protocol was used in all 13 centers: representative sampling was by random selection of vendors and a sample of foods bought from each of these vendors at a time and date selected at random. Microbiological analyses were carried out using standardized Association Française de Normalisation methods, and the use of a standardized questionnaire to collect data concerning the characteristics of the vendors. Fifteen surveys were carried out, with 3,003 food samples from 1,268 vendors. The proportion of unsatisfactory food samples was between 12.7 and 82.9% for ice creams and sorbets and between 11.3 and 92% for sandwiches. For ice creams and sorbets, the sale of a large number of units (>80 per day) increased the risk of unsatisfactory food by a factor of 2.8 (95% confidence interval [CI]: 1.5 to 5.1), lack of training in food hygiene by 6.6 (95% CI: 1.1 to 50). and by a factor of 2.8 (95% CI: 1.4 to 5.4) for mobile vendors. These risk factors were not identified for sandwiches, this difference may be due to the presence of a cooking step in their preparation. These results show that the poor microbiological quality of these street foods constitutes a potential hazard to public health, that the extent of this hazard varies between the cities studied, and that vendors' health education in food safety is a crucial factor in the prevention of foodborne infections.

[Microbiological quality of street-vendor ice cream in Dakar]. / Qualité microbiologique des glaces vendues sur la voie publique à Dakar.

During a multicenter study initiated by the International Network of Pasteur Institutes and Associated Institutes, microbiological quality of street-vended ice creams in Dakar was evaluated. 313 samples of ice creams from 170 street-vendors were collected and tested for common foodborne pathogens and indicator organisms. Results showed that microbiological quality of 45% of tested samples was unsatisfactory because of large populations of aerobic mesophilic organisms (36.7%), thermotolerant coliforms bacteria (21.4%) and sometimes E. coli. (10.6%). Strict pathogens as Salmonella, Shigella and Vibrio cholerae were not found. An investigation conducted among vendors showed a lack of education and training; these vendors need information about food preparation and storage practices that reduce microbiological contamination of foods.

Behavior of Listeria spp. in smoked fish products affected by liquid smoke, NaCl concentration, and temperature.

The growth, survival, and death of Listeria monocytogenes were studied in a synthetic medium as a function of temperature, NaCl content, and amount of liquid smoke, and the findings were validated in smoked fish products. The smoke preservative compound was simulated by adding liquid smoke, and the concentration was expressed as phenol concentration. The growth of L. monocytogenes was limited at a temperature as low as 4 degrees C or at a phenol concentration as high as 20 ppm. The predicted values were obtained using a mathematical model established in liquid medium in a previous study. They accurately fit values observed in L. monocytogenes challenge tests on smoked fish. After 21 days of storage the deviation between the predicted and experimental values was within 0.5 log for 60% of the data. This model may be useful in predicting Listeria contamination in smoked fish. Moreover, this study emphasizes the importance of phenol concentration to control the growth of Listeria spp. in smoked food products.

Modelling the growth, survival and death of Listeria monocytogenes.

In this paper, the predictive microbiology approach has been generalized to the study of growth, survival and death of Listeria monocytogenes. As this micro-organism is involved in food poisoning, its growth, survival and death were studied as functions of low temperatures, NaCl and phenol compounds, in a synthetic medium, by a factorially designed experiment. A significant inactivation of L. monocytogenes was obtained with 20 ppm of phenol and 4% (w/v) NaCl at temperatures from 4 to 12 degrees C. An empirical model is proposed to describe, in a single step, the biomass profile vs studied factors. Thereby, the influence of temperature, NaCl and phenol concentration on L. monocytogenes biomass quantity (0.5-8 log cfu ml(-1)) are presented as a function of storage duration. The comparisons of the proposed model with existing models (Gompertz for growth, vitalistic for survival and death) were performed. The use of a single equation allows the prediction of contamination levels in all experimental conditions without knowledge a priori. The model offers considerable prospects for its use in food microbiology.

Increased capillary permeability in systemic rheumatoid vasculitis: detection by dynamic fluorescence nailfold videomicroscopy.

OBJECTIVE: Several histological studies suggest a vascular involvement in rheumatoid arthritis (RA). We evaluated morphological and functional changes of skin capillaries in patients with RA. METHODS: We studied capillary permeability by nailfold fluorescence videomicroscopy in patients with RA with and without systemic vasculitis to establish the sensitivity, specificity, and the prognostic value of the technique for the diagnosis of systemic rheumatoid vasculitis (SRV). Nine patients with SRV, 22 patients with active RA without signs of vasculitis, and 16 controls were evaluated. RESULTS: No difference in conventional capillaroscopy was observed when we compared patients with SRV and RA. Using fluorescence videomicroscopy after intravenous injection of fluorescein sodium, we observed an increase of transcapillary dye diffusion in 9/9 patients with SRV, in 13/22 patients with RA without vasculitis and in 4/16 control patients. Our results give a sensitivity of 100% in SRV, a specificity of 44%, a positive predictive value of 34% and a negative predictive value of 100%. CONCLUSION: Our present study points out the functional alteration of the capillary wall in patients with RA with or without vasculitis and suggests the usefulness of dynamic fluorescence nailfold capillaroscopy in patients with RA when systemic vasculitis is suspected, not as a diagnostic tool, but because of the high negative predictive value of the technique.

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.

[Significance of arterial Doppler in Horton's disease. Prospective study of 59 case reports]. / Intérêt du Doppler artériel dans la maladie de Horton. Etude prospective de 59 observations.

Several preliminary studies drew attention to the value of Doppler examination in temporal arteritis. This study involving 59 cases aimed to define the value of Doppler examination in the diagnosis of the disease, evaluation of ophthalmic risk and in the monitoring of treatment. The study involved 59 patients and 47 controls with no evidence of temporal arteritis, but of comparable mean age. The following arteries were investigated before treatment: arteries of limbs, subclavian, vertebral, carotid, temporal, occipital, facial and ophthalmic recorded via the internal nasal branch and also transocularly. The results were expressed in the form of a score from 0 to 3 describing the degree of deterioration of the curves. A mean score corresponding to the mean of the scores of the cephalic arteries was calculated for each patient and each control. The specificity and sensitivity of the investigation were studied, based on this mean score by ROC analysis. The progression under treatment was monitored for more than 24 months in 20 patients divided into 3 groups: group I: 6 patients cured; group II: 6 patients with late recurrence of temporal arteritis after steroid withdrawal; group III: 8 patients with progressive disease. 81.5% of temporal arteries were pathological, including 60% with tight stenosis (score 2 and 3). Morphological anomalies in the curves were also noted at the level of the occipital arteries (69%), facial arteries (80%), as well as the ophthalmic artery at both recording sites (internal nasal: 84.5%, transocular: (73%) (table I).(ABSTRACT TRUNCATED AT 250 WORDS)

Sex differences in latencies of bilateral electrodermal responses.

The present study examined sex differences in the latencies of bilateral electrodermal responses to stimuli presented in monocular vision. The stimuli were spatial-emotional, verbal-emotional, spatial-neutral and verbal-neutral slides, presented for either 35 ms or 1 s. Subjects were 15 males and 15 females. Bilateral latencies were not influenced by type of stimulus or by right/left hemisphere stimulation, which is in keeping with the most recent findings of bilateral electrodermal activity studies. However, females gave a faster right hand than left hand response and appeared to be more lateralized than males. Males showed shorter latencies on the left hand than on the right. These results confirm the importance of gender in experiments using the bilateral recordings of electrodermal activity.

Methodological problems in bilateral electrodermal research.

Since the beginning of the 1970's, bilaterally recorded electrodermal activity (EDA) has generated a significant amount of research. It has been used in studies of hemispheric asymmetry, as well as in psychiatry as an indicator of left and right hemisphere activity. However an examination of the various studies which have utilized this technique does not show an overall consensus, and the results, as well as their interpretations, are often contradictory. These difficulties can partially be explained in terms of problems of methodology and interpretation. The aim of this paper is to review the methodological considerations, which have been grouped into 3 categories: stimulus specificity; the selection of subjects; and the measurement and interpretation of EDA.

Asymmetry of electrodermal activity: a review.

Before the seventies, with a few exceptions, electrodermal activity had been studied only unilaterally, presuming symmetry. Only in the seventies do a growing number of authors take an interest in electrodermal asymmetry, due in part to the enthusiasm evoked by theories of hemispheric specialization. The purpose of this paper is to clarify and summarize the data - often contradictory - collected on this subject and to point out some remaining problems.

[Survival of microorganisms frozen on solid medium (author's transl)]. / Survie de microorganismes congelés sur milieu solide.

Different freezing methods have been studied for 12 microorganisms. This study has been carried out on solid support in the conditions near the freezing of foods. The survival rates are on relation with species and freezing methods. The survival of some microorganisms during a storage at -20 degrees C has been studied.