Exploring a new approach for assessing the fate and behavior of the tailings released by the Brumadinho dam collapse (Minas Gerais, Brazil)

In 2019, the Brumadinho dam rupture released a massive amount of iron ore mining tailings into the Paraopeba River. Up to now, it remains a public health issue for the local and downstream populations. The present study aims to assess the behavior and fate of metal contamination following the disaster. Using new sampling strategies and up-to-date geochemistry tools, we show that the dissolved metal concentrations (< 0.22 µm cutoff filtration) remained low in the Paraopeba River. Although the tailings present high metal concentrations (Fe, Mn, Cd, and As), the high local background contents of metals and other previous anthropogenic contamination hamper tracing the sediment source based only on the geochemical signature. The Pb isotopic composition coupled with the metals enrichment factor of sediments and Suspended Particulate Matter (SPM) constitutes accurate proxies that trace the fate and dispersion of tailing particles downstream of the dam collapse. This approach shows that 1) The influence of the released tailing was restricted to the Paraopeba River and the Retiro Baixo reservoir, located upstream of the São Francisco River; 2) The tailings' contribution to particulate load ranged from 17 % to 88 % in the Paraopeba River; 3) Other regional anthropogenic activities also contribute to water and sediment contamination of the Paraopeba river.

Prolonged impact of the COVID-19 pandemic on self-harm hospitalizations in France: A nationwide retrospective observational study

Background

The first wave of the COVID-19 pandemic in France was associated with a reduced number of hospitalizations for self-harm, with the exception of older people. The on-going pandemic may have both sustained and delayed effects.

Methods

Data were extracted from the French national hospital database (PMSI), a nationwide exhaustive database. The number of self-harm hospitalizations (ICD-10 codes X60–84) between September 1, 2020 and August 31, 2021 (N = 85,679) was compared to 2019 (N = 88,782) using Poisson regression models.

Results

There was a decrease in the total number of self-harm hospitalizations during the studied period versus 2019 (−3.5%; Relative Risk [RR] [95% Confidence Intervals] = 0.97 [0.96–0.97]; p < 0.0001). However, sex and age effects were identified. While adults aged 30–59-years-old showed a decrease (monthly decreases: −12.6 to −15.0%), we found an increase in adolescent girls (+27.7%, RR = 1.28 [1.25–1.31]; p < 0.0001), notably since January 2021. Moreover, the numbers were similar to 2019 in adolescent boys, in youths aged 20–29 years, and in people aged 70 and more. Hospitalizations in intensive care units decreased (−6.7%, RR = 0.93 [0.91–0.96]; p < 0.0001) and deaths at hospital following self-harm remained stable (+0.6%, Hazard Ratio = 0.99 [0.91–1.08], p = 0.79).

Conclusions

During this second stage, the number of self-harm hospitalizations remained at a lower level than in the prepandemic period. However, significant variations over time, age, and sex were observed. Young people (notably adolescent girls) appear to have particularly suffered from the persistence of the pandemic, while older people did not show any decrease since the beginning. Vigilance and continuing prevention are warranted.

New insights into metal(loid) dynamics in the Doce River estuary (Brazil) after a massive iron ore-processing tailing dam collapse

The present study investigated metal and metalloid dynamics in the estuarine water of the Doce River (Brazil) after the collapse of an iron ore-processing tailing dam in 2015. Spectroscopic and isotopic techniques were applied to bring new insights into the effects of the dam failure on the dynamics and hazardousness of particulate and dissolved metal(loid) concentrations along the fluvial-estuarine continuum. Spectroscopic analysis showed that the suspended particulate matter (SPM) of the Doce River estuary consisted of a combination of soil-delivered particles and fine tailing mud particles with small amounts of coarse tailing mud Fe oxides (~150-μm width). Enrichment and contamination factors showed that the dam failure increased particulate Fe, Pb, Cd, and As, and dissolved Pb concentrations. Total concentrations of As (15 μg/L), Pb (30 μg/L), Cd (8 μg/L), and Cr (105 μg/L) increased up to values higher than quality and regulatory guidelines. Human health risk assessment showed that local communities are exposed to a potentially chronic Cr noncarcinogenic effects, although Cr high concentrations were not linked with the dam failure by this study. The particulate Pb isotope signatures reported herein (^206/207Pb ratios of 1.214 ± 0.006 and ^208/206Pb ratios of 2.025 ± 0.011) can be applied to constrain metal(loid) sources in the Doce River sediment plume and continental shelf. The river-ocean mixing zone caused abrupt changes metal(loid) partitioning (Zn, Pb, Cr, Cu, Cd, and As), controlling their fate in the estuary and the Brazilian southeast coastal.

Impact of the COVID-19 pandemic on preterm birth and stillbirth: A nationwide, population-based retrospective cohort study

Objective

This study aimed to establish whether there was a decrease in the rate of prematurity in France after the beginning of lockdown (March 17, 2020) and whether there was an increase in the rate of stillbirths compared with 2017 to 2019.

Study design

We included all births from January to September of each year from 2017 to 2020 from the national Programme de Médicalisation des Systèmes d’Information database: 496,171 newborns from women with singleton pregnancies and 15,441 newborns from women with multiple pregnancies were included for 2020. Concerning the 2017 to 2019 period, we included a mean of 518,798 newborns from women with singleton pregnancies and 16,441 newborns from women with multiple pregnancies per year.

Results

Between April to May 2017 to 2019 and April to May 2020, there was a decrease of - 7.53% in the rate of prematurity (from 5.31% to 4.91%; P < 0.01) for singleton pregnancies. Between these 2 periods, the rate of change was −12.90% between 22 and 27 WG (P = 0.03), +1.96% between 28 and 31 WG (P = 0.69), and −8.24% between 32 and 36 WG (P < 0.01). The decrease in the rate of prematurity was still observed after the end of lockdown (from June to September 2020). For multiple births, there was no decrease in prematurity between January to September 2017 to 2019 and January to September 2020: 50.14% vs. 50.36% (P = 0.63), respectively, for twins and 95.51% vs. 94.9% (P = 0.62), respectively, for high-order multiple pregnancies. In January to September, there were 363 stillbirths among singleton pregnancies in 2017 to 2019 and 114 in 2020 (0.00% change rate). Among the 1752 women with a diagnosis of SARS-CoV-2 infection with singleton pregnancies, the rate of prematurity was higher in 2020 than in 2017 to 2019 (9.93% vs. 5.32%; P < 0.01), regardless of the severity of prematurity (P < 0.05 for all).

Conclusion

Large-scale socioenvironmental modifications like the lockdown in spring 2020 may be associated with beneficial effects on perinatal morbidity. We did not find an increase in the rate of stillbirth since the beginning of the pandemic. At this stage, the practical consequences are not obvious, but our results encourage further reflection regarding behaviors that could modify the risk of prematurity outside of the context of an epidemic.

Hospitalisations pour AVC en France pendant la pandémie de COVID-19 avant, pendant, et après le premier confinement

Introduction

Méthodes

Résultats

Discussion/Conclusion

Self-harm hospitalization following bariatric surgery in adolescents and young adults

BACKGROUND

While bariatric surgery has demonstrated physical and psychological benefits, a risk of suicide and non-fatal self-harm has also been shown. The aim of this study was to compared the rate of hospitalization for self-harm during a three-year observational follow-up period between adolescents/young adults who underwent bariatric surgery in France in 2013-2014 and two control groups.

METHODS

All individuals aged 12-25 years old who underwent bariatric surgery in France between January 1st, 2013, and December 31st, 2014, were identified with a validated algorithm from the French national hospital database, and compared to a healthy sample of the general population matched for age and gender. Information relative to hospitalizations, including for self-harm (ICD-10 codes X60-84), were extracted i) between 2008 and the surgery, and ii) for a three-year follow-up period. A second unmatched control group with obesity but no bariatric surgery was also identified. Survival analyses with adjustments for confounding variables were used.

RESULTS

In 2013-2014, 1984 youths had bariatric surgery in France. During follow-up, 1.5% were hospitalized for self-harm vs. 0.3% for controls (p < 0.0001). After adjustment, subsequent hospitalization for self-harm was associated with bariatric surgery (HR 3.64, 95% CI 1.70-7.81), prior psychiatric disorders (HR 7.76, 95% CI 3.76-16.01), and prior self-harm (HR 4.43, 95% CI 1.75-11.24). When compared to non-operated youths with obesity, bariatric surgery was not associated with self-harm while prior mental disorders and self-harm were. Mortality reached 0.3% after surgery.

CONCLUSIONS

Bariatric surgery is associated with an increased risk of self-harm, mainly in relation to preexisting psychological conditions. Vigilance and appropriate care are thus warranted in vulnerable individuals.

The effects of the COVID-19 lockdown and socio-economic factors on stroke hospitalizations in France

Background

Worldwide, the COVID-19 pandemic has been associated with a drop in overall stroke hospitalizations. Additionally, there is a well-known association between stroke and socioeconomic status. This study aims to assess the COVID-19 effect on stroke admissions in France during the first national lockdown and investigate the factors associated with its spatial heterogeneity.

Methods

In this retrospective nationwide study, we used data from the French hospital discharge database (PMSI) to estimate rates of admission for stroke to all public and private hospitals in 2019 and 2020. We used negative binomial regression to test for a nationwide change in stroke admissions during the first lockdown, compared to the same period in 2019 (from week 12 to week 19). We conducted a multivariate analysis to explore the factors associated with the stroke admission incidence rate ratio variation (2020 incidence rate/2019 incidence rate) at the county level.

Results

We found a significant nationwide reduction in stroke admissions during the first wave of COVID-19 (incidence rate ratio 0,91 [0,86 - 0.97]), with notable geographic variations. After adjustment on hospital bed capacity, cumulative in-hospital COVID-19 incidence, standardized death rate at age 65 and unemployment rate, a higher share of labourers at the county level was associated with a higher incidence rate ratio (p < 0.01).

Conclusions

During the first national lockdown, there has been an overall decrease in stroke admission rates. Socio-economic determinants such as low-skilled jobs were independently associated with an increase in the stroke admission incidence rate ratio, while we did not find any independent effect from the local COVID 19 burden and hospital capacities.

Key messages

The first national lockdown led to an overall decrease in stroke admissions in France.

This decrease varied between counties according to socio-economic determinants.

Early exposure of pregnant women to non-steroidal anti-inflammatory drugs delivered outside hospitals and preterm birth risk: nationwide cohort study

OBJECTIVE

To assess the risk of preterm birth associated with nonsteroidal anti-inflammatory drugs (NSAIDs), focusing on early exposure in the period from conception to 22 weeks of gestation (WG).

DESIGN

National population-based retrospective cohort study.

SETTING

The French National Health Insurance Database that includes hospital discharge data and health claims data.

POPULATION

Singleton pregnancies (2012-2014) with a live birth occurring after 22WG from women between 15 and 45 years old and insured the year before the first day of gestation and during pregnancy were included. We excluded pregnancies for which anti-inflammatory medications were dispensed after 22WG.

METHODS

The association between exposure and risk of preterm birth was evaluated with GEE models, adjusting on a large number of covariables, socio-demographic variables, maternal comorbidities, prescription drugs and pregnancy complications.

MAIN OUTCOME MEASURES

Prematurity, defined as a birth that occurred before 37WG.

RESULTS

Among our 1 598 330 singleton pregnancies, early exposure to non-selective NSAIDs was associated with a significantly increased risk of preterm birth, regardless of the severity of prematurity: adjusted odds ratio (aOR) = 1.76 (95% CI 1.54-2.00) for extreme prematurity (95% CI 22-27WG), 1.28 (95% CI 1.17-1.40) for moderate prematurity (28-31WG) and 1.08 (95% CI 1.05-1.11) for late prematurity (32-36WG), with non-overlapping confidence intervals. We identified five NSAIDs for which the risk of premature birth was significantly increased: ketoprofen, flurbiprofen, nabumetone, etodolac and indomethacin: for the latter, aOR = 1.92 (95% CI 1.37-2.70) with aOR = 9.33 (95% CI 3.75-23.22) for extreme prematurity.

CONCLUSION

Overall, non-selective NSAID use (delivered outside hospitals) during the first 22WG was found to be associated with an increased risk of prematurity. However, the association differs among NSAIDs.

TWEETABLE ABSTRACT

French study for which early exposure to non-selective NSAIDs was associated with increased risk of prematurity.

[Readmissions after lung resection in France: The PMSI database]

BACKGROUND

Readmission within 30 days is an indicator of the quality of care, because it often reflects post-discharge care that is not optimal. The objective of this work is to measure over time on the one hand the readmission rate and on the other hand the number of hospitals with a standardized readmission rate beyond the national average.

METHOD

All patients with major pulmonary resection for lung cancer in France were extracted from the PMSI national database. Readmission within 30 days was defined as any new hospitalization either in the same hospital or in another establishment.

RESULTS

From January 1, 2005 to December 31, 2018, 110,603 patients were included. The 30-day all-cause readmissions rate was 24.9% (n=27,540). Patients after pneumonectomy had a readmission rate of 37% (n=4918) and 23% after lobectomy (n=2684) (P<0.0001). For the first period, we counted 10 hospitals with a standardized readmissions rate above the 99.8 limit and 10 hospitals above the 95% limit. For the second period, 8 hospitals had a standardized readmission rate above the 99.8% limit and 11 hospitals above the 95% limit. For the third period, 7 hospitals had a standardized readmission rate above the 99.8% limit and 6 hospitals above the 95% limit.

CONCLUSION

Readmissions to hospital 30 days after major lung resection for cancer in France declined little during these three periods. Measures to prevent readmissions should be introduced.

Will applications on smartphones allow a generalization of telemedicine?

Background

Telemedicine is one of the healthcare sectors that has developed the most in recent years. Currently, telemedicine is mostly used for patients who have difficulty attending medical consultations because of where they live (teleconsultation) or for specialist referrals when no specialist of a given discipline is locally available (telexpertise). However, the use of specific equipment (with dedicated cameras, screens, and computers) and the need for institutional infrastructure made the deployment and use of these systems expensive and rigid. Although many telemedicine systems have been tested, most have not generally gone beyond local projects.

Our hypothesis is that the use of smartphones will allow health care providers to overcome some of the limitations that we have exposed, thus allowing the generalization of telemedicine.

Main body

This paper addresses the problem of telemedicine applications, the market of which is growing fast. Their development may completely transform the organization of healthcare systems, change the way patients are managed and revolutionize prevention. This new organization should facilitate the lives of both patients and doctors.

In this paper, we examine why telemedicine has failed for years to take its rightful place in many European healthcare systems although there was a real need. By developing the example of France, this article analyses the reasons most commonly put forth: the administrative and legal difficulties, and the lack of funding. We argue that the real reason telemedicine struggled to find its place was because the technology was not close enough to the patient.

Conclusion

Finally, we explain how the development of smartphones and their current ubiquitousness should allow the generalization of telemedicine in France and on a global scale.

Individual Versus Area Level Social Risk Measurement in the General French Population

Background

Ongoing health policy changes include a move towards alternative delivery and payment models. In addition, the emphasis is put on social determinants as part of performance measurement and payment calibration. Most payers and policy makers rely on area-level socio-economic data, which can lead to sub-optimal. However, little is known about the agreement between individual and area-level variables. The objective was to assess the agreement between individual and area-level social risk variables in the general French population.

Methods

We used data from the CONSTANCES general-purpose cohort, a randomly selected representative sample of French adults aged 18-69 years. Data collected include socioeconomic and demographic characteristics, behaviors, and health data. We assessed the correlation or agreement between individual and area-level variables for 4 dimensions: household annual pretax income, secondary education completion, occupational group (workers), and unemployment.

Results

115,263 individuals were included in the study, 53% female and aged 48 years on average. The median annual household income was 42,000 Euros (USD 50,400), 73% had completed secondary education, 7% were unemployed, and 9.3% were workers. The correlation between income measured at the individual and area level was positive but moderate (Rho=0.20; p &lt; 0.01). Individuals having completed secondary education had a higher area-level median completion rate compared to those having a lower education level (48% versus 41%; p &lt; 0.01). Unemployed individuals had a slightly higher area-level median unemployment rate compared to employed ones (11% versus 10%; p &lt; 0.01). Lastly, workers had a higher area-level median probability to be a worker rate compared to other individuals ones (25% versus 18%; p &lt; 0.01).

Conclusions

In the general French population, area-level socio-economic variables are poor proxies for individual-level social risk.

Key messages

Area-level socio-economic data is a poor proxy for individual data. Researchers and policy makers should move towards individual data.

Automatic Record Hash Coding and Linkage for Epidemiological Follow-up Data Confidentiality

A protocol is proposed to allow linkage of anonymous medical information within the framework of epidemiological follow-up studies. The protocol is composed of two steps; the first concerns the irreversible transformation of identification data, using a one-way hash function which is used after spelling processing. To avoid dictionary attacks, two large random files of keys, called pads, are introduced. The second step consists in the linkage of files rendered anonymous. The weight given to each linkage field is estimated by a mixture model, the likelihood of which being maximized with the Expectation and Maximization (EM) algorithm. The performance of this method has been assessed by comparing record linkage, based on exclusive use of the automatic procedure, with a manual linkage, obtained by the Burgundy Registry of Digestive Cancers. The result of the linkage of a file of 2,847 cancers with a file of 388,614 hospitalization stays in the Dijon university hospital showed a sensitivity of 97% and a specificity of 93%.

Improving Model Robustness with Bootstrapping

Objective: Recent results published by Coste et al. in discriminant analysis with ordinal responses showed the superiority of optimal discriminating analysis for ordinal responses (ODAO) both in terms of classification and simplicity of implementation compared to classic methods (Fisher’s discrimination, logistic regression) applied to medical data (prognostics of burns) and to simulated data. Nevertheless, the solutions obtained by ODAO may be sensitive to re-sampling (i.e the estimated coefficients by ODAO may show excessive sensitivity to the training sample). This study proposes some solutions to control the fluctuations of sampling and to ensure model stability.

Methods: We used intensive computational methods and bootstrapping, at the outset of model building in order to reduce the sampling variability of estimated coefficients. Thus, the estimation of the coefficients was not based on the minimization of a classification criterion of the training sample, but on the minimization of an aggregate criterion of bootstrapped replications of a classification criterion. Five aggregate criteria were studied.

Results: The improvement in terms of robustness appeared in 30% of the test cases with moderate training sample size and 55% of those with small training sample size.

Conclusion: Simulated test cases showed that bootstrapping can help construct more robust models in difficult classification situations and small training samples which are particularly frequent.

Decision Analysis for the Assessment of a Record Linkage Procedure

Objectives: According to European legislation, we must develop computer software allowing the linkage of medical records previously rendered anonymous. Some of them, like AUTOMATCH, are used in daily practice either to gather medical files in epidemiologic studies or for clinical purpose. In the first situation, the aim is to avoid homonymous errors, and in the second one, synonymous errors. The objective of this work is to study the effect of different parameters (number of identification variables, phonetic treatments of names, direct or probabilistic linkage procedure) on the reliability of the linkage in order to determine which strategy is the best according to the purpose of the linkage.

Methods: The assessment of the Burgundy Perinatal Network requires the linking of discharge abstracts of mothers and neonates, collected in all the hospitals of the region. Those data are used to compare direct and probabilistic linkage, using different parameterization strategies.

Results: If the linkage has to be performed in real time, so that no validation of indecisions generated by probabilistic linkage is possible, probabilistic linkage using three variables without any phonetic treatment seems to be the most appropriate approach, combined with a direct linkage using four variables applied to non-conclusive links. If a validation of indecisions is possible in an epidemiological study, probabilistic linkage using five variables, with a phonetic treatment adapted to the local language has to be preferred. For medical purpose, it should be combined with a direct linkage with four or five variables.

Conclusion: This paper reveals that the time and money available to manage indecision as well as the purpose of the linkage are of paramount importance for choosing a linkage strategy.

[The REDSIAM network]

The French national health database (SNIIRAM) proved to be very useful for epidemiology, health economics, evaluation, surveillance or public health. However, it is a complex database requiring important resources and expertise for being used. The REDSIAM network has been set up for promoting the collaboration of teams working on the Sniiram. The main aim of REDSIAM is to develop and validate methods for analyzing the Sniiram database for research, surveillance, evaluation and public health purposes by sharing the knowledge and experience of specialized teams in the fields of diseases identification from the Sniiram data. The work conducted within the network is devoted to the development and the validation of algorithms using Sniiram data for identifying specific diseases. The REDSIAM governance includes the Steering Committee composed of the main organizations in charge of producing and using the Sniiram data, the Bureau and the Technical Committee. The network is organized in thematic working groups focused on specific pathological domains, and a charter defines the rules for participation in the network, the functioning of the thematic working groups, the rules for publishing and making available algorithms. The articles in this special issue of the journal present the first results of some of the thematic working groups.

Early screening for type 2 diabetes following gestational diabetes mellitus in France: hardly any impact of the 2010 guidelines

AIMS

Women who had gestational diabetes mellitus (GDM) have a high risk of type 2 diabetes mellitus (T2DM) in the years following pregnancy. Most follow-up screening studies have been conducted in limited geographical areas leading to large variability in the results. The aim of our investigation was to measure how the publication of guidelines affected early screening for T2DM after a pregnancy with GDM during the period 2007-2013, in France.

METHODS

We conducted a retrospective cohort study in a representative sample of 1/97th of the French population using data from the "National Health Insurance Inter-Regime Information System," which collects individual hospital and non-hospital data for healthcare consumption.

RESULTS

The sample included 49,080 women who gave birth in 2007-2013. In the following 3 months, only 18.49% of women with GDM had an oral glucose tolerance test or a blood glucose test in 2007. This rate had not significantly increased in 2013 (p = 0.18). The proportion of women with GDM who had the recommended glycemic follow-up at 3 months (20.30 vs. 21.58%, p = 0.19) and 6 months (32.48 vs. 37.16%, p = 0.08) was not significantly different before the guidelines (2008-2009) and after the guidelines (2012-2013). At 12 months, the difference was significant (46.77 vs. 54.05%, p = 0.009).

CONCLUSION

Postpartum screening has improved only slightly since the guidelines and remains largely insufficient, with less than 25% of women with GDM screened in the first 3 months. In the first year after delivery, less than 60% of women were screened for T2DM.

[Study of algorithms to identify schizophrenia in the SNIIRAM database conducted by the REDSIAM network]

BACKGROUND

The aim of the REDSIAM network is to foster communication between users of French medico-administrative databases and to validate and promote analysis methods suitable for the data. Within this network, the working group "Mental and behavioral disorders" took an interest in algorithms to identify adult schizophrenia in the SNIIRAM database and inventoried identification criteria for patients with schizophrenia in these databases.

METHODS

The methodology was based on interviews with nine experts in schizophrenia concerning the procedures they use to identify patients with schizophrenia disorders in databases. The interviews were based on a questionnaire and conducted by telephone.

RESULTS

The synthesis of the interviews showed that the SNIIRAM contains various tables which allow coders to identify patients suffering from schizophrenia: chronic disease status, drugs and hospitalizations. Taken separately, these criteria were not sufficient to recognize patients with schizophrenia, an algorithm should be based on all of them. Apparently, only one-third of people living with schizophrenia benefit from the longstanding disease status. Not all patients are hospitalized, and coding for diagnoses at the hospitalization, notably for short stays in medicine, surgery or obstetrics departments, is not exhaustive. As for treatment with antipsychotics, it is not specific enough as such treatments are also prescribed to patients with bipolar disorders, or even other disorders. It seems appropriate to combine these complementary criteria, while keeping in mind out-patient care (every year 80,000 patients are seen exclusively in an outpatient setting), even if these data are difficult to link with other information. Finally, the experts made three propositions for selection algorithms of patients with schizophrenia.

CONCLUSION

Patients with schizophrenia can be relatively accurately identified using SNIIRAM data. Different combinations of the selected criteria must be used depending on the objectives and they must be related to an appropriate length of time.

Postpartum hemorrhage with transfusion: Trends, near misses, risk factors and management at the scale of a perinatal network

OBJECTIVES

To analyze temporal trends and management of postpartum hemorrhage (PPH) with transfusion and its related maternal near-miss (MNM) cases between 2006 and 2014 and to study risk factors.

MATERIAL AND METHODS

This retrospective cohort study from two prospective databases included 156,047 women giving birth in all the maternity hospitals of Burgundy. We analyzed temporal trends and the distribution of PPH with transfusion, the circumstances of transfer of patients between hospitals and factors associated with PPH with transfusion. PPH with massive blood transfusion and/or non-medical treatment was defined as MNM. Statistical analysis included Chi² tests and logistic regression for multivariate analysis.

RESULTS

The overall rate of PPH with transfusion was 7.3‰ and globally increased during the study period whereas the MNM rate did not. MNM represented 37% of patients with PPH with transfusion and 71% of transferred patients, but surgical treatments were performed before transfer. Factors associated with PPH with transfusion were maternal age>35 years (odds ratio [OR]=1.3), prematurity (OR=5.0), cesarean section (OR=4.8), placenta previa (OR=22.0), twin pregnancy (OR=6.6), HELLP syndrome (OR=17.9) and severe small-for-gestational-age infants (OR=2.0). The first four were also associated with MNM.

CONCLUSION

MNM cases of PPH rates were steady in Burgundy while rates of PPH with transfusion increased moderately.

Detection of temporal clusters of health care-associated infections or colonizations with Pseudomonas aeruginosa

We investigated temporal clusters of Pseudomonas aeruginosa cases between 2005 and 2014 in 1 French university hospital, overall and by ward, using the Kulldorff method. Clusters of positive water samples were also investigated at the whole hospital level. Our results suggest that water outlets are not closely involved in the occurrence of clusters of P aeruginosa cases.

Association between Pseudomonas aeruginosa positive water samples and healthcare-associated cases: nine-year study at one university hospital

OBJECTIVE

To study the association between the results of water samples and Pseudomonas aeruginosa healthcare-associated cases in a French university hospital.

METHODS

Generalized Estimating Equations were used on complete case and imputed datasets. The spatial unit was the building and the time unit was the quarter.

RESULTS

For the period 2004-2013, 2932 water samples were studied; 17% were positive for P. aeruginosa. A higher incidence of P. aeruginosa cases was associated with a higher proportion of positive water samples (P=0.056 in complete case analysis and P=0.031 with the imputed dataset). The association was no longer observed when haematology and intensive care units were excluded, but was significant in analyses of data concerning intensive care units alone (P<0.001).

CONCLUSION

This study suggests that water outlet contamination in hospitals can lead to an increase in healthcare-associated P. aeruginosa cases in wards dealing with susceptible patients, but does not play a significant role in other wards.

An Isotopic Exchange Kinetic Model to Assess the Speciation of Metal Available Pool in Soil: The Case of Nickel

In this study an innovative approach is proposed to predict the relative contribution of each mineral phase to the total metal availability in soils, which, in other words, could be called the available metal fractionation. Through the use of isotopic exchange kinetics (IEK) performed on typical Ni bearing phases (i.e., two types of serpentines, chlorite, smectite, goethite, and hematite) the isotopic exchange and metal-solid interaction processes are connected, considering both the thermodynamic and kinetic aspects. Results of Ni IEK experiments on mineral phases are fitted with a pseudo-first order kinetic model. For each Ni bearing phase, this allows to (i) determine the number and size of exchangeable pools (E_Ni(i)), (ii) assess their corresponding kinetic constants (k_(i)), and (iii) discuss the mechanism of Ni isotopic exchange at mineral surfaces. It is shown that all the phases investigated, with the only exception of hematite, present at least two distinct reactive pools with significantly different k_(i) values. Results suggest also that metal involved in outer-sphere complexes would display isotopic exchange between 100 and 1000 times faster than metal involved in inner-sphere complexes, and that the presence of high and low affinity sites may influence the rate of isotopic exchange up to 1 order of magnitude. Moreover, the method developed represents a tool to predict and estimate Ni mobility and availability in natural soil samples on the basis of soil mineral composition, providing information barely obtained with other techniques.