[Prioritising the risk of foodborne zoonoses using a quantitative approach: application to foodborne bacterial hazards in pork and beef]. / Hiérarchiser les risques de zoonoses alimentaires: une approche quantitative. Application aux dangers bactériens transmis par les viandes porcine et bovine.

Foodborne zoonoses are a major public health concern. Risk analysis, which underpins international policies on food safety and trade in foodstuffs of animal origin, requires that an assessment be made of the occurrence and severity of human cases for each type of foodstuff. However, the tools currently available for quantifying risks are only capable of estimating the consequences of certain diseases. This article proposes an alternative quantitative approach for prioritising the risk of foodborne zoonoses, based on the creation of a typology of hazards and calculating a risk score. A combination of average hospitalisation and mortality rates is used to quantify the severity of human cases. By calculating the percentage of food-associated cases it is possible to estimate the incidence of cases linked specifically with the foodstuff being assessed. This method is illustrated by applying it to bacterial zoonotic hazards in pork and beef and provides a support tool for veterinary public health decision-makers.

Recovery methods for detection and quantification of Campylobacter depend on meat matrices and bacteriological or PCR tools.

Campylobacter is one of the main causes of human foodborne bacterial disease associated with meat consumption in developed countries. Therefore, the most effective approach for recovery and detection of Campylobacter from meat should be determined. Two hundred ninety pork skin and chine samples were inoculated with Campylobacter jejuni NCTC 11168 and two strains of Campylobacter coli. Campylobacter cells were then recovered from suspensions and enumerated by direct plating. Campylobacter recovery was evaluated by comparing results for two methods of sample collection (swabbing and mechanical pummeling) and three recovery fluids (peptone water, 5% glucose serum, and demineralized water). End-point multiplex PCR was performed to evaluate the compatibility of the recovery fluids with direct PCR detection techniques. Mean recovery ratios differed significantly between pork skin and chine samples. Ratios were higher for mechanical pummeling (0.53 for pork skin and 0.49 for chine) than for swabbing (0.31 and 0.13, respectively). For pork skin, ratios obtained with peptone water (0.50) and with glucose serum (0.55) were higher than those obtained with demineralized water (0.16). Significant differences were not observed for chine samples. Direct multiplex PCR detection of Campylobacter was possible with pork skin samples. The tools for Campylobacter recovery must be appropriate for the meat matrix to be evaluated. In this study, less than 66% of inoculated Campylobacter was recovered from meat. This underestimation must be taken into account for quantitative risk analysis of Campylobacter infection.

[Remifentanil-midazolam compared to sufentanil-midazolam for ICU long-term sedation]. / Rémifentanil-midazolam versus sufentanil-midazolam pour la sédation prolongée en réanimation.

OBJECTIVE: Remifentanil has a unique metabolic pathway that holds potential benefits for long-term sedation. We compared remifentanil-midazolam to sufentanil-midazolam in 41 critically ill adults requiring mechanical ventilation. STUDY DESIGN: Randomized double-blind trial. PATIENTS AND METHODS: Infusion rates were titrated every 4 hours to achieve the desired Ramsay score. Five fold increases in dose requirement was considered as the development of tolerance. Drugs requirement, development of tolerance and weaning time of ventilation were compared. RESULTS: The study was stopped after an interim analysis. The remifentanil and sufentanil groups were comparable regarding IGS II: 56+/-22 vs 64+/-26, mean+/-SD, ICU length of stay: 26 (8-45) vs 19 (11-34) days, and sedation duration: 6 (4-19) vs 6 (3-16)days, median [interquartile range, IQR]). There was a shorter weaning time in the remifentanil group as compared to sufentanil group: 22 h (12-53) vs 96 (47-142) h, median [IQR], p=0.04). The daily opioid infusion rate needed to be decreased over time only in sufentanil group, p < 0.001. Tolerance occurred in 6 (30%; CI(95), 10 to 40%) remifentanil and no sufentanil patients (P=0.02). CONCLUSION: Sufentanil infusion needed to be reduced over time and prolonged the weaning time when compared to remifentanil.

A comprehensive immunotopographic map of human thymus.

We have achieved a comprehensive immunotopographic mapping of human thymus by using a large battery of monoclonal antibodies and the methodological refinement of comparative serial tissue section immunohistochemistry, allowing analysis of multiple phenotypes in the same tissue site. Previous immunohistochemical studies of thymus have concentrated on the majority T-cell and epithelial cell populations. Besides demonstrating the complexity of T-cell antigenic expression (e.g., simultaneous cortical expression of Leu 2, Leu 3, CALLA, Tdt, and Leu 6), we delineate surprisingly complex B-cell zones (e.g., septal B-follicles with DRC+C3d+ dendritic cells and zonal maturation of B-cells). Whereas septal B-follicles were found in 25% of cases, medullary B-cells were universally present as a substantial minority component. This expanded immunotopographic knowledge of the complex T-, B-, epithelial, and reticulum cell neighborhoods suggests that the thymus is an organ capable of a broad repertoire of immunological responses, not limited to T-cell development.

Effects of doxapram on hypercapnic response during weaning from mechanical ventilation in COPD patients.

Failure of weaning from mechanical ventilation in COPD patients is often related to diaphragmatic fatigue. Whether there is a central respiratory drive fatigue and a reserve of excitability is still debated. The purpose of this study was to analyze the following in 13 COPD patients weaned from mechanical ventilation: (1) ventilatory (VE/PETCO2) and neuromuscular (P0.1/PETCO2) response to hypercapnia; (2) the maximum reserve capacity measured through changes in the VE/PETCO2 and P0.1/PETCO2 slopes after doxapram (DXP) infusion, which, given during the test, allows measurement of the maximum response capacity to overstimulation; and (3) analyze the influence of these changes on the outcome of weaning. The results show a variable P0.1/PETCO2 response and a low VE/PETCO2. DXP infusion does not change the slopes of these relations but increases the end-expiratory volume (delta FRCd); (p less than 0.02). Since there was no change in the VE/PETCO2, P0.1/PETCO2, and delta FRC values with or without DXP, there was no excitability reserve in patients who were successfully weaned. When weaning failed, DXP did not change VE/PETCO2 and P0.1/PETCO2 slope, but delta FRCd was greater the delta FRC (p less than 0.001). The excitability reserve in these patients leads to an increase in end-expiratory volume, probably worsening the diaphragm dysfunction.

Steady-state breathing pattern responses to small inspiratory resistive loads in COPD patients. Application to weaning from mechanical ventilation.

We investigated the effect of small inspiratory resistive loads on the breathing patterns of patients with COPD admitted to the ICU for acute respiratory failure. Patients were in stable clinical condition three days after weaning from the acute-phase ventilation. Healthy nonsmokers served as controls. Breathing patterns were recorded for 20-min periods during unloaded breathing (R0), then with small inspiratory resistive loads (R1 = 2.5 cmH2O L/s and R2 = 5.2 cmH2O L/s) applied in random order. Respiratory parameters were memorized in real time and blood gases measured continuously with a transcutaneous PO2/PCO2 monitor and compared periodically with arterial blood gases. Minute volume (VE) and respiratory rate decreased with no modification in blood gas values. In the COPD patients, R1 was too small to be perceived; when R2 was applied, no increase in TI was observed, and VT and VT/TI decreased. The VE could not be maintained despite a shortening of expiratory time. The COPD patients did not have significant increase of occlusion pressure (P0.1). Mean blood gas values did not change during the testing, but the coefficient of variation of tcPCO2 increased. During the critical period following weaning from artificial ventilation, COPD patients did not respond in the same manner as normal subjects to inspiratory resistive loads, but did not have modified gas exchange during the 20-min period.

Accuracy of a composite score using daily SAPS II and LOD scores for predicting hospital mortality in ICU patients hospitalized for more than 72 h.

UNLABELLED: In most databases used to build general severity scores the median duration of intensive care unit (ICU) stay is less than 3 days. Consequently, these scores are not the most appropriate tools for measuring prognosis in studies dealing with ICU patients hospitalized for more than 72 h. PURPOSE: To develop a new prognostic model based on a general severity score (SAPS II), an organ dysfunction score (LOD) and evolution of both scores during the first 3 days of ICU stay. DESIGN: Prospective multicenter study. SETTING: Twenty-eight intensive care units (ICUs) in France. PATIENTS: A training data-set was created with four ICUs during an 18-month period (893 patients). Seventy percent of the patients were medical (628) aged 66 years. The median SAPS II was 38. The ICU and hospital mortality rates were 22.7% and 30%, respectively. Forty-seven percent (420 patients) were transferred from hospital wards. In this population, the calibration (Hosmer-Lemeshow chi-square: 37.4, P = 0.001) and the discrimination [area under the ROC curves: 0.744 (95 % CI: 0.714-0.773)] of the original SAPS II were relatively poor. A validation data set was created with a random panel of 24 French ICUs during March 1999 (312 patients). MEASUREMENTS AND MAIN RESULTS: The LOD and SAPS II scores were calculated during the first (SAPS1, LOD1), second (SAPS2, LOD2), and third (SAPS3, LOD3) calendar days. The LOD and SAPS scores alterations were assigned the value "1" when scores increased with time and "0" otherwise. A multivariable logistic regression model was used to select variables measured during the first three calendar days, and independently associated with death. Selected variables were: SAPS II at admission [OR: 1.04 (95 % CI: 1.027-1.053) per point], LOD [OR: 1.16 (95 % CI: 1.085-1.253) per point], transfer from ward [OR: 1.74 (95 % CI: 1.25-2.42)], as well as SAPS3-SAPS2 alterations [OR: 1.516 (95 % CI: 1.04-2.22)], and LOD3-LOD2 alterations [OR: 2.00 (95 % CI: 1.29-3.11)]. The final model has good calibration and discrimination properties in the training data set [area under the ROC curve: 0.794 (95 % CI: 0.766-0.820), Hosmer-Lemeshow C statistic: 5.56, P = 0.7]. In the validation data set, the model maintained good accuracy [area under the ROC curve: 0.826 (95 % CI: 0.780-0.867), Hosmer-Lemeshow C statistic: 7.14, P = 0.5]. CONCLUSIONS: The new model using SAPS II and LOD and their evolution during the first calendar days has good discrimination and calibration properties. We propose its use for benchmarking and evaluating the over-risk of death associated with ICU-acquired nosocomial infections.

[Severity of illness explains the inadequacy between diagnosis-related groups and intensive care patients. Groupe GHM]. / La gravité de l'atteinte explique l'inadéquation entre le système des groupes homogènes de malades et les patients de réanimation. Groupe GHM.

OBJECTIVE: To assess the relationship between diagnosis related groups (DRG) and severity of illness in intensive care unit (ICU) patients in semf1tical and economical terms. STUDY DESIGN: Prospective, multicentric study including 13 medical and surgical ICUs for adults. MATERIAL: Discharge reports of 3,215 ICU admissions including age, gender, diagnosis, organ system failures, length of stay (LOS) and severity of illness evaluated with severity scores (SS): simplified acute physiological score (SAPS). Apache II, Glasgow score and physiological score (PS). METHODS: Semantical homogeneity was evaluated from the percentage of well-classified patients established from the comparison between the official computerized method and a non-computerized method applied by three clinical experts. Economical homogeneity was evaluated from the relationship between SS and LOS. RESULTS: In total, 88% (CI: 87.7-88.2) of ICU stays were classified in eight main categories of diagnosis (MCD). According to the MCD, the percentage of well-classified patients varied from 28% (CI: 27.6-28.3) to 97% (CI: 96.8-97.1), decreasing with the association of several diagnoses and organ system failures. There was a large variability in the LOS of DRG and a significant correlation between LOS and SS was found in only 8/16 DRG. CONCLUSION: The fact that the severity of illness is not taken into account in the elaboration of DRGs explains the inadequacy of the DRG system in intensive care.

[Initial evaluation of thoracic injuries. Comparison of pulmonary radiography and x-ray computed tomography]. / Bilan initial des traumatismes thoraciques. Comparaison de la radiographie pulmonaire et de la tomodensitométrie.

OBJECTIVES: To investigate the contribution of computed tomography scan (CTS) to the initial évaluation of chest trauma. PATIENTS AND METHODS: We carried out a two-year prospective study in all the chest trauma patients admitted to ICU. They underwent both Chest X-ray (CXR) and CTS within 24 jours of admission. CXR and CTS images were read by achieving a consensus between two radiologists who were unaware of the results of the other investigation. Then we compared these findings with the treatment received by the patients in the ICU. RESULTS: From July 1, 1991 through July 1, 1993, 56 patients were included (21 with conventional CTS and 35 with helicoidal CTS). CTS demonstrated a significant number of pleural (p < 0.001), parenchymatous (p < 0.001), and mediastinal (p < 0.01) lesions that escaped detection on CXR (CTS+/CXR- lesions). Thoracic drainage was done in 16 patients because of abnormalities CTS+/CXR- (p < 0.01); six patients with CTS+/CXR- pulmonary contusions received Pressure Positive Ventilation (p < 0.01); and four CTS+/CXR- lesions were treated surgically (p < 0.05). CONCLUSION: CTS adds significantly to the evaluation of chest trauma by allowing prompt, accurate assessment of lesions. In this study, over 50% of these lesions required specific treatment during the ICU stay.

[Severe cardiac decompensation: value in the early hours of a combination of amrinone and dobutamine]. / Décompensation cardiaque sévère: intérêt dans les premières heures de l'association amrinone et dobutamine.

Ten patients with severe chronic heart failure (class III and IV of the NYHA classification) received treatment for severe heart failure with dobutamine (10, then 15 micrograms.kg-1.min-1), then with dobutamine combined with amrinone (7.5, then 10 micrograms.kg-1.min of each). Used alone, dobutamine improves cardiac performance (cardiac index from 1.8 +/- 0.24 l.min-1.m-2 to 2.65 +/- 0.44 l.min-1.m-2). These results are further improved when amrinone is associated with dobutamine. Blood pressure increases with dobutamine and no decrease is recorded when amrinone is introduced, despite a gradual decrease in systemic arterial resistances. Pulmonary artery wedge pressure shows a significant decrease only when the strongest dose of the combined drugs is used. However, this positive effect is counterbalanced by an increase in pulse frequency. Side effects, be it on the blood count (platelets count reduced from 255,600 +/- 3974 mm-3 to 207,400 +/- 3380 mm-3 with no clinic sign) or cardiovascular activity (one case of premature ventricular contraction; one case of transient junctional rhythm), do not require the suspension of treatment. Thus, the dobutamine-amrinone combination treatment seems a promising one.

On-farm multi-contamination of pigs by food-borne bacterial zoonotic hazards: an exploratory study.

Application of risk analysis to control pork-borne zoonoses on farms is a major aim of the current European food safety legislation. The prevalence, levels of contamination and variations in pig contaminations according to herds and batches must therefore be studied to define relevant methods for control of zoonoses. The aims of this exploratory study were to provide information on the prevalence and levels of infection of finisher/fattening pigs by Campylobacter spp., Clostridium perfringens, Listeria monocytogenes, Salmonella enterica and Staphylococcus aureus, and to quantify the respective effects of batches and herds. One hundred and twenty-seven pooled fresh feces samples and 120 pooled cutaneous swab samples were tested from 37 batches in 14 farrowing-to-finishing farms. Campylobacter spp. was identified in all fecal samples on farms whereas L. monocytogenes was never found. C. perfringens was identified in 48% of samples, Salmonella in 2%, and S. aureus in 48%. The decomposition of variance of on-farm prevalence and levels of contamination and a general linear model showed a systematically significant effect of herd, and an effect of batch only for levels of contamination with Campylobacter and C. perfringens and for prevalence of S. aureus. The contamination status of pigs seems to be mainly explained by herd status linked to poor biosecurity measures. Further studies are needed to explain such correlations in order to define farm indicators for food-borne zoonotic hazards.