Physiological proteins in resource-limited herbivores experiencing a population die-off.

Nutrient availability is predicted to interact with herbivore population densities. Competition for low quality food at high density may reduce summer food intake, and in turn winter survival. Conversely, low population density may favor physiological recovery through better access to better quality spring forage. Here, we take advantage of the long-term study of the Soay sheep population of St. Kilda (Scotland) to measure plasma protein markers and immunity in two consecutive summers with contrasting population densities. We show that, following a winter die-off resulting in a shift to low population density, albumin and total proteins increased, but only in adult sheep. The effect was not solely attributable to selective disappearance of malnourished sheep. Similarly, the concentration of antibodies was higher following the die-off, potentially indicating recovery of immune function. Overall, our results are consistent with the physiological recovery of surviving individuals after a harsh winter.

Toxicodynetics in nordiazepam and oxazepam overdoses.

OBJECTIVES: Toxicodynetics aims at defining the time-course of major clinical events in drug overdose. We report the toxicodynetics in mono-intoxications with oxazepam and nordiazepam. METHODS: Cases of oxazepam or nordiazepam overdoses collected at the Paris poison control centre from 1999 to 2014 on the basis of self-report. A particular attention was paid to eliminate the concomitant alcohol or psychotropic co-ingestions. The toxicodynetic parameters were assessed as previously described. Results are expressed using 10-90 percentiles. In adults, the dose was normalized (TI, toxic Index) by dividing the supposed ingested dose by the maximal recommended dose. RESULTS: Two hundred and fifty-one and 74 cases of oxazepam and nordiazepam poisonings were included, respectively. The Emax for oxazepam and nordiazepam were sleepiness or obtundation in 106 and 36 cases, respectively. Coma was used to qualify only one oxazepam overdose. The median delay in onset of the Emax was 1.5h (0.33-15) in nordiazepam and 4h (0.5-15) in oxazepam overdose. In both overdoses, the onset of Emax occurred on an "on-off" mode. In adults, the greatest TIs in nordiazepam and oxazepam overdoses were 45 and 26.7, respectively. The TI in the oxazepam-induced coma was 26.7, the largest dose. CONCLUSION: Data collected in PCC allow determining a number of toxicodynetic parameters. Toxicodynetics showed that nordiazepam is not a cause of coma even in large overdose while oxazepam causes coma only at a very high dose. Deep coma in nordiazepam overdose whatever the dose and deep coma in overdose with oxazepam involving TI less than 20 result from unrecognized drug-drug interaction.

Evolution of transgenerational immunity in invertebrates.

Over a decade ago, the discovery of transgenerational immunity in invertebrates shifted existing paradigms on the lack of sophistication of their immune system. Nonetheless, the prevalence of this trait and the ecological factors driving its evolution in invertebrates remain poorly understood. Here, we develop a theoretical host-parasite model and predict that long lifespan and low dispersal should promote the evolution of transgenerational immunity. We also predict that in species that produce both philopatric and dispersing individuals, it may pay to have a plastic allocation strategy with a higher transgenerational immunity investment in philopatric offspring because they are more likely to encounter locally adapted pathogens. We review all experimental studies published to date, comprising 21 invertebrate species in nine different orders, and we show that, as expected, longevity and dispersal correlate with the transfer of immunity to offspring. The validity of our prediction regarding the plasticity of investment in transgenerational immunity remains to be tested in invertebrates, but also in vertebrate species. We discuss the implications of our work for the study of the evolution of immunity, and we suggest further avenues of research to expand our knowledge of the impact of transgenerational immune protection in host-parasite interactions.

Occupational allergic contact dermatitis and major allergens in France: temporal trends for the period 2001-2010.

BACKGROUND: Occupational allergic contact dermatitis (OACD) is one of the most common occupational skin diseases in developed countries, but data about its temporal trends in incidence remain sparse. OBJECTIVES: The aim of this study is to describe OACD trends in terms of industrial activities and main causal agents in France over the period 2001-2010. MATERIALS AND METHODS: Data were collected from the French National Network of Occupational Disease Vigilance and Prevention (RNV3P, Réseau National de Vigilance et de Prévention des Pathologies Professionnelles). All OACD considered probably or certainly associated with an occupational exposure were included in the study. Trends were examined (i) on annual crude numbers of OACD and (ii) on reported odds ratios of OACD calculated using logistic regression models. RESULTS: Overall, 3738 cases of OACD were reported and the mean age of OACD cases was 35 years, 52% being women. The most frequent occupations were hairdressers, health care workers, cleaning staff and masons. The total number of OACD cases remained stable over the study period, but increases in OACD related to isothiazolinones (P = 0·002), epoxy resins (P = 0·012) and fragrances (P = 0·005) were observed. Conversely, decreases were noted for cement compounds (P = 0·002) and plant products (P = 0·031). These trends highlight specific sectors and exposures at risk of OACD. CONCLUSIONS: Trends in OACD depend on the nature of exposure. Observed decreases were consistent with prevention measures taken during the study period, and the increases observed serve to highlight those areas where preventative efforts need to be made to reduce skin allergies in the workplace.

Risk assessment of dimethylfumarate residues in dwellings following contamination by treated furniture.

Recently, numerous cases of dermatitis induced by dimethylfumarate (DMFu) have been reported in Europe. DMFu has been used to prevent mold development in various items, although it is not registered as a biocide. In France, from October 2008 to December 2009, more than 100 cases were reported. Despite a ban on articles containing DMFu and the removal of potentially contaminated products, some people were still suffering from dermatitis or other health problems. The French Agency for Food, Environmental and Occupational Health & Safety was mandated to assess whether the existence in the past of DMFu-contaminated items in dwellings could continue to pose a threat to the health of inhabitants. A risk assessment was performed based on the classical risk analysis approach for environmental contaminants. Hazard assessment of DMFu with regard to its sensitizing properties was performed, based on human case reports collected in France between January 2009 and February 2010. For around half of the 132 individual cases reported, the causal link to DMFu was considered at least probable. An Organisation for Economic Co-Operation and Development (OECD) local lymph node assay performed in a study on mice showed strong sensitizing potential for DMFu. Exposure was assessed by measuring DMFu in items sampled in preselected dwellings. These investigations demonstrated that DMFu exposure can persist after removal of the primary contaminated items. We therefore concluded that there was clearly a risk of skin reactions in patients previously sensitized to DMFu. Furthermore, the available data do not support the existence of significant health effects through the respiratory route.

Comparison of wave overtopping estimation models for urban beaches. Towards an early warning system on the Basque coast.

This study compares the performance of different wave overtopping estimation models at urban beaches. The models selected for comparison are the Mase et al. (2013) and EurOtop parametric models and the XBeach process-based model in surfbeat and non-hydrostatic mode. Seven energetic storms are selected between 2015 and 2022 with offshore significant wave height ranging between 3 m and 8 m and peak period between 12 s and 20 s to perform the model comparison. The information required to run and validate the models (beach slope, shoreface shape, absence/presence of overtopping) was collected for each storm from coastal videometry. To account for the uncertainties derived from the incident waves randomness and the bathymetry shape when using the process-based model, a series of simulations with random seed boundary conditions were run over two different realistic profile shapes for each storm. The present study is a pilot study on the beach of Zarautz; however, it can be extended to other beaches of the Basque coast. Results indicate that while Mase et al. (2013) and EurOtop tend to reasonably predict the absence or presence of overtopping events, they tend to underestimate the hazard level at the beach of Zarautz. Additionally, the beach underwater profile shape can affect the process-based model performance at intermediate intensity storms and to a lesser extend during moderate storms. Finally, the hazard level at the beach of Zarautz varies significantly alongshore due to the configuration of the seawall, highlighting the need for local adaptation measures. Considering that there is no model that systematically performs better than others, it might be reasonable to use model assemble techniques to draw conclusions from a probabilistic perspective.

Social association predicts immunological similarity in rewilded mice.

Environmental influences on immune phenotypes are well-documented, but our understanding of which elements of the environment affect immune systems, and how, remains vague. Behaviors, including socializing with others, are central to an individual's interaction with its environment. We tracked behavior of rewilded laboratory mice of three inbred strains in outdoor enclosures and examined contributions of behavior, including social associations, to immune phenotypes. We found that the more associated two individuals were, the more similar their immune phenotypes were. Social association was particularly predictive of similar memory T and B cell profiles and was more influential than sibling relationships or worm infection status. These results highlight the importance of social networks for immune phenotype and reveal important immunological correlates of social life.

Maternal antibody persistence: a neglected life-history trait with implications from albatross conservation to comparative immunology.

The evolution of different life-history strategies has been suggested as a major force constraining physiological mechanisms such as immunity. In some long-lived oviparous species, a prolonged persistence of maternal antibodies in offspring could thus be expected in order to protect them over their long growth period. Here, using an intergenerational vaccination design, we show that specific maternal antibodies can display an estimated half-life of 25 days post-hatching in the nestlings of a long-lived bird. This temporal persistence is much longer than previously known for birds and it suggests specific properties in the regulation of IgY immunoglobulin catabolism in such a species. We also show that maternal antibodies in the considered procellariiform species are functional as late as 20 days of age. Using a modelling approach, we highlight that the potential impact of such effects on population viability could be important, notably when using vaccination for conservation. These results have broad implications, from comparative immunology to evolutionary eco-epidemiology and conservation biology.

Level of agreement between Nexfin non-invasive arterial pressure with invasive arterial pressure measurements in children.

BACKGROUND: We compared Nexfin non-invasive arterial pressure measurements using a novel small finger cuff with intra-arterial pressure in the paediatric setting in order to establish the level of agreement between both methods. METHODS: The study included 41 children aged 2-16 yr admitted for surgery or paediatric intensive care with an intra-arterial catheter as part of standard monitoring. Values of systolic (SAP), diastolic (DAP), and mean arterial pressure (MAP) were obtained simultaneously from the intra-arterial catheter and the non-invasive Nexfin monitor. Data were analysed using intra-class correlation (ICC) coefficients and the Bland-Altman analysis. RESULTS: A non-invasive arterial pressure signal was obtained in the majority of patients. The reproducibility of arterial pressure measurements over time by both non-invasive and invasive techniques was high, with ICC coefficients ranging from 0.94 to 0.98. The Bland-Altman analysis for SAP, DAP, and MAP revealed a bias with 95% limits of agreement of -13.5 (-39.7; +12.8), -0.2 (-12.8; +13.2), and -2.6 (-17.7; +12.5) mm Hg, respectively. Linear regression suggested a weak correlation of SAP and the bias between intra-arterial and Nexfin SAP measurements (intercept 4.9 mm Hg, ß -0.29; P=0.01). CONCLUSIONS: Nexfin non-invasive arterial pressure measurements are feasible in paediatric patients. Nexfin accurately reflects the intra-arterial MAP and DAP curves, but seems to underestimate SAP compared with intra-arterial pressure. These results suggest that Nexfin may be used in low-to-moderate risk children without severe systemic hypotension, who require beat-to-beat haemodynamic monitoring but do not have an indication for invasive measurements.

[Determining factors in lowering blood lead levels below the poisoning threshold in Greater Paris (1992-2006)]. / Déterminants du retour à une plombémie inférieure au seuil d'intoxication en Ile-de-France (1992-2006).

BACKGROUND: Given the serious health effects of lead poisoning (Pb> or =10microg/dL), the present study was designed to estimate the time required to reach and identify factors associated with reaching Pb<10microg/dL according to the severity of the poisoning. METHODS: Since 1992, the Greater Paris lead poisoning monitoring system (SSSILF) has been systematically recording data on blood lead levels of screening and follow-up testing of children in the region. In children under the age of seven when screened positive for lead poisoning, survival curves without reaching the threshold of 10microg/dL and the relative risk (RR) of reaching this threshold were calculated (Kaplan-Meier curves and Cox model), according to blood lead level groups (Group 4: Pb> or =45microg/dL; Group 3: 25microg/dL< or =Pb<45microg/dL; Group 2: 10microg/dL< or =Pb<25microg/dL; (by definition, Group 1: Pb<100microg/L and risk factors of poisoning). RESULTS: The median survival times without reaching the threshold of Pb<10microg/dL were 72.7 months for Group 4, 36.8 months for Group 3 and 14.5 months for Group 2. Compared to reference categories, the time to Pb<10microg/dL was longer for children aged four and over at the time they screened positive for poisoning (Groups 4 and 3), for children displaying pica behavior (Groups 3 and 2), for children in an environment with another child suffering from lead poisoning (Groups 3 and 2) and for children of mothers from Sub-Saharan or North Africa countries (Group 2); the differences reached statistical significance. Changes in Pb levels were better for all children (Groups 4, 3 and 2) screened over the most recent period, i.e. 2002 to 2006, and for Group 2 children living in Paris or the nearby district of Seine-Saint-Denis. CONCLUSION: While the time required has gone down over recent years, the time to reach the threshold of Pb<10microg/dL is counted in years and varies depending on known poisoning risk factors and the district responsible for patient management. It is essential to have early lead poisoning screening for children in high-risk groups and then follow-up after rapid implementation of appropriate medical and social measures.

[Occurrence of lead poisoning during follow-up of children at risk with initial screening lead blood levels below 100 microg/L]. / Risque de survenue d'une intoxication par le plomb lors du suivi d'enfants à risque dont la plombémie de primodépistage est inférieure à 100 microg/L.

BACKGROUND: Follow-up is recommended for children initially screened with a lead blood level below the threshold for lead poisoning of 10 microg/dL when they have one or more risk factors. At first, the frequency of a follow-up lead blood test was calculated in children at risk for lead poisoning. In second time, we calculated the rate of occurrence and independent factors for lead poisoning in the follow-up group. METHODS: Since 1992, the Greater Paris lead poisoning monitoring system (SSSIILF) has been systematically recording data on lead levels in blood tests conducted for screening and follow-up in Greater Paris. Children initially screened before the age of seven whose blood lead level was inferior to 10 microg/dL and who had one or more risk factors were selected. The association between qualitative variables and a follow-up lead blood test was compared using the Chi(2) test. For children given follow-up, the association between qualitative variables and occurrence of lead poisoning was compared using the Chi(2) test; independent factors for lead poisoning were estimated by logistic regression. RESULTS: A follow-up lead blood test was more frequent and the difference was statistically significant, for children with one or more of the following risk factors identified at the time of screening: home address in Seine Saint-Denis or central Paris, screened in mother/child healthcare centers (PMI) or through a private physician, a blood lead level 5 microg/dL on initial screening, young age (<24 months) at the time of screening and some others known risk factors. The rate of occurrence of lead poisoning during follow-up was 25.9% for children screened between 1992 to 1994 and decrease to 5.1% for children screened in 2004 to 2005 (p<0.001) and was lower in central Paris and Seine Saint-Denis than in other districts in Greater Paris (p<0.01). The rate of occurrence during follow-up, independent of known risk factors for lead poisoning (p<0.01), was higher for children screened before the age of two (p<0.01) and for children whose mothers were from Sub-Saharan Africa (p<0.01). CONCLUSION: It is essential to follow up children at risk with an initial lead blood level below 10 microg/dL, especially those initially screened before the age of 24 months. Local action on home environment could also be needed when the initial blood lead level is 5 microg/dL and more than one risk factor has been identified.

Follow-up of children suffering from lead poisoning or at risk of lead poisoning in Greater Paris, 1992--2002.

BACKGROUND: It is essential for children suffering from or at risk of lead poisoning to have regular follow-up, and specifically for their blood lead (Pb) levels to be monitored. The present study assessed the occurrence of late follow-up testing of blood lead levels in children in Greater Paris, and factors related to such delays. METHODS: Since 1992, the SSSIILF has been systematically recording data on lead levels in blood tests conducted for screening and follow-up in Greater Paris. For Pb greater or equal to 45 microg/dL (Group 4), a further blood lead test has to be done within three weeks. For levels of 25 microg/dL < or = Pb < 45 microg/dL (Group 3) and 10 microg/dL < or = Pb < 25 microg/dL (Group 2), a second test must be done within 6 months. For Pb less than 10 microg/dL combined with one or more risk factors (Group 1: children at risk of poisoning), a second test is required within 6 to 12 months. Children aged 1 to 6 years who were screened between 1992 and 2002 were selected. The occurrence of late follow-up testing was estimated, and the independent effect of each variable associated with a delay was measured using a logistic regression model. RESULTS: Delays in re-testing were reported for 66.9% of Group 4 children (n=356), 45.3% of Group 3 children (n=921), 74.1% of Group 2 children (n=5,466), and 88.7% of Group 1 children (n=15,612). In the three groups with Pb greater or equal to 10 microg/dL, there was better follow-up (i.e. less delay to re-testing) for children screened most recently, those whose initial blood lead test results were elevated, those who lived in sub-standard housing built before 1949, and those who lived in suburban districts of Paris. The delay was longer for children aged 4 to 6 compared to younger children. When the size of the group was large enough, these differences were significant. In Group 1, similar results were observed except for a home address in a suburban district. Furthermore, follow-up was better for children of Sub-Saharan African parents, children whose initial prescription had been issued by a "PMI" mother/child healthcare centre and children from large families. CONCLUSION: Despite substantial delays in carrying out follow-up blood lead level testing, these delays were shorter for the populations with the greatest exposure.

Poisoning by non-edible squash: retrospective series of 353 patients from French Poison Control Centers.

CONTEXT: Among the numerous varieties of squash that exist, some are edible while other bitter-tasting ones are not fit for human consumption. Cases of confusion seem to be multiplying and are characterized by digestive problems (diarrhea, vomiting, and abdominal pain). METHODS: This is a descriptive retrospective study of cases of exposure reported to French Poison Control Centers between 1 January 2012 and 12 December 2016. RESULTS: 353 patients were included, with 71.7% belonging to collective cases of poisoning. The male to female sex ratio was 0.75 for an average age of 38.2 ± 23.6 years. The circumstances of exposure were dietary for 337 patients (95.5%). The majority of the squash consumed was purchased at a store (55.8%) but some also came from the garden (25.5%). 204 patients (57.8%) mostly presented with diarrhea, vomiting, abdominal pain, sometimes with the consequent dehydration, hypotension, tachycardia, headaches, or vertigo. There were no deaths or severe (Poisoning Severity Score (PSS) 3) cases, but there were 14 patients (4.0%) of moderate severity, 190 patients (53.8%) of minor severity (PSS 1), and 149 patients (42.2%) without severity (PSS 0) but among which we include the bitter taste of the squash. The average age of PSS 2 patients was significantly (p = .003) older than that of the PSS <2 patients. CONCLUSION: As the first consequential series in Europe, our study shows that exposure to non-edible squash is frequent. Usually benign, poisoning could be the consequence of the irritating effect of certain cucurbits, the molecules responsible for the taste and toxicity of the fruits. In terms of prevention therefore, we recommend disposing of any squash with a bitter taste.

[Occupational rhinitis]. / Rhinites professionnelles.

INTRODUCTION: Rhinitis is one of the most common occupational diseases. It is often neglected by those affected because it causes little disability. It is poorly understood by doctors who have insufficient experience of occupational diseases and their causes. However it is often the first manifestation of a respiratory disorder that may cause physical complications and socio-economic disability. BACKGROUND: Numerous diverse agents are potential causes of rhinitis. The diagnosis of occupational rhinitis should be considered when sneezing, rhinorrhoea or nasal obstruction are associated with work. The causal agent can be identified by ta-king a careful history. When the mechanism of the disease is immunologic the suspected antigen can be confirmed by skin testing, specific IgE or nasal provocation. The respiratory disorder of which rhinitis is the first manifestation may progress to asthma if the exposure continues. The prevention of occupational rhinitis depends on the reduction of exposure to allergens and/or irritants. When it has developed removal of the causative agent is essential to prevent progression to asthma.

Robust extraction of quantitative structural information from high-variance histological images of livers from necropsied Soay sheep.

Quantitative information is essential to the empirical analysis of biological systems. In many such systems, spatial relations between anatomical structures is of interest, making imaging a valuable data acquisition tool. However, image data can be difficult to analyse quantitatively. Many image processing algorithms are highly sensitive to variations in the image, limiting their current application to fields where sample and image quality may be very high. Here, we develop robust image processing algorithms for extracting structural information from a dataset of high-variance histological images of inflamed liver tissue obtained during necropsies of wild Soay sheep. We demonstrate that features of the data can be measured in a fully automated manner, providing quantitative information which can be readily used in statistical analysis. We show that these methods provide measures that correlate well with a manual, expert operator-led analysis of the same images, that they provide advantages in terms of sampling a wider range of information and that information can be extracted far more quickly than in manual analysis.

The INSERM expert review on glycol ethers: findings and recommendations.

The use of glycol ethers and their effects on health have recently attracted the attention of the French health authorities. At their request, INSERM, the French Institute of Health and Medical Research, conducted a collective expertise review on glycol ethers in 1999. INSERM Expertise Reviews are independent procedures performed by experts from several disciplines, to guarantee the objectivity and the relevance of the report. During several work sessions, the experts carried out a critical analysis of and reviewed studies concerning the toxicity of glycol ethers. This process resulted in a series of recommendations and conclusions. All these data have been published in the form of a report and have been used to help the public authorities to make decisions on how to prevent risks for professionals and consumers.

[Health effects of diesel exhaust: a state of the art]. / Effets sur la santé des émissions des moteurs diesel: revue des connaissances.

INTRODUCTION: This review presents the state of knowledge regarding the acute and chronic toxicity of diesel engine exhaust in humans. STATE OF ART: The health effects of diesel engine exhaust, which is a complex mixture of gas and particulate matter (ultrafine and fine particles), are mainly irritation of the respiratory tract and carcinogenicity. They may also facilitate the development of respiratory allergies. A recent reassessment by the International Agency for Research on Cancer concluded that there is sufficient evidence of a causal association between exposure to diesel engine exhaust and lung cancer. PERSPECTIVES: The epidemiologic data collected during the last two decades also show limited evidence of increased risks of bladder cancer, as well as of chronic obstructive pulmonary disease in diesel engine exhaust exposed workers. Both experimental and epidemiological studies have involved the effect of emissions from traditional diesel engine technology. Major developments in this technology have occurred recently and the toxicity of emissions from these new engines is still to be characterized. CONCLUSION: Further studies are needed to explore the link between diesel engine exhaust exposure and the risks of bladder cancer, as well as of chronic obstructive pulmonary disease and respiratory allergies. Research is also needed to get more information about the toxicity of the new diesel technology emissions.

[Poisoning with Jatropha curcas: 24 cases reported to Paris and Marseille Poisons Centers]. / Intoxications par pignons d'Inde (Jatropha curcas): 24 observations rapportées aux centres antipoison de Paris et Marseille.

Jatropha curcas L. is an inedible plant belonging to the Euphorbiaceae family that is growing in subtropical zones of all continents. We report a series of 24 cases of poisoning with J. curcas seeds or fruits reported to poison centers in Paris and Marseille between December 2000 and June 2014. Fifteen adults and 9 children ingested J. curcas seeds or fruits. All patients experienced gastrointestinal disorders, within the first hours following ingestion: nausea, vomiting, diarrhea and abdominal pain. Laboratory investigations performed in 10 patients revealed minor abnormalities: CK elevation (8 cases), dehydration (5 cases) with moderate elevation of serum creatinine levels (3 cases), and mildly increased serum bilirubin (8 cases). Complete remission of all clinical signs was observed within 48 hours in the 20 cases for which the outcome was known. Previously published cases of J. curcas poisoning were very similar to ours: As in our series, gastrointestinal disorders were always present. They were sometimes associated with neurological or cardiovascular signs, and hepatic or renal disorders; these were generally interpreted as complications of severe gastroenteritis, although direct toxic effects could not be formally excluded. In most cases, simple supportive measures were sufficient to ensure complete recovery within 24-48 hours. J Curcas poisoning incidence is certainly increasing because the plant is cultivated to produce biodiesel and is now largely present in most subtropical countries. As a consequence, local health professionals should be informed of the toxic properties of this plant.

Selective digestive decontamination by erythromycin-base in a polyvalent intensive care unit.

OBJECTIVE: To study the effect of selective digestive tract decontamination by erythromycin-base on the incidence of carriage and infection with MR Enterobacteriaceae producing an extended spectrum beta-lactamase (ESB). DESIGN: After a 10-week prospective survey to ascertain the baseline incidence in two bays (1 and 3) of the same ICU, bay 1 was compared with bay 3 during a further survey of 6 months. The patients in bay 1 received erythromycin-base. SETTING: Two non-contiguous bays, 1 and 3, of 4 beds, in the same polyvalent ICU of a university hospital. PATIENT: Consecutive patients with unit stay longer than 2 days; 34 patients were included during the control period, 43 in bay 1 (decontamination) and 46 in bay 3 (control) during the trial period. INTERVENTION: Erythromycin-base, 1 g t.i.d. in powder form administered by gastric tube to patients in bay 1 from admission to discharge. MEASUREMENTS AND RESULTS: Digestive tract carriage was monitored by cultures of gastric and rectal swab specimens, sampled twice a week. Enterobacteriaceae were isolated on Drigalski agar with incorporated ceftazidime (4 mg/l). In bay 1 there was a decrease in ESB producing Enterobacteriaceae (23% vs 10%, p = 0.0004) from rectal swab, especially in K. pneumoniae (15% vs 2%, p = 10(-5)), during the decontamination period in comparison to the control period. During the trial period the only differences observed between bays 1 and 3 were in the gastric samples: K. pneumoniae were less often isolated in bay 1 than in bay 3 (0% vs 3%, p = 0.03). Intestinal carriage with multiresistant Enterobacteriaceae occurred in 28% patients in bay 1 and 30% patients in bay 3 during the trial period (p = 0.79). Erythromycin-base did not delay the carriage by patients in bay 1 (log rank test p = 0.42). CONCLUSION: Erythromycin-base was not effective in preventing digestive tract carriage due to Enterobacteriaceae resistant to third generation cephalosporin by production of chromosomal cephalosporinase. The decrease in isolates containing K. pneumoniae in bay 1 cannot be definitively attributed to erythromycin-base, since the number of this species in bay 3 was low.