Occupational exposure to organic solvents and the risk of developing testicular germ cell tumors (TESTIS study): Effect of combined exposure assessment on risk estimation

OBJECTIVES

Etiological factors of testicular germ cell tumors (TGCT) remain largely unknown, but a causal role of occupational exposures to solvents has been suggested. Previous studies analyzing these exposures reported discordant results, potentially related to exposure assessment methods. The aim of this study was to investigate the role of occupational exposure to solvents on the risk of developing TGCT among young men.

METHODS

This study examined occupational exposures to solvents and TGCT risk based on the lifetime work histories of 454 cases and 670 controls, aged 18-45 years, of the French national TESTIS case-control study. Solvent exposure was estimated using: (i) exposure assignment by job-exposure matrix (JEM) and (ii) JEM combined with self-reported exposure data from specific questionnaires (SQ) and expert assessment (EA). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression models.

RESULTS

Both approaches (JEM and JEM+SQ+EA) showed a consistent association between TGCT and trichloroethylene exposure (exposed versus not exposed; JEM=OR 1.80 [95% confidence interval (CI) 1.12-2.90] and JEM+SQ+EA= OR 2.59 (95% CI 1.42-4.72). Both approaches also observed positive associations with ketone esters and fuels & petroleum-based solvents.

CONCLUSION

The results suggest that some organic solvents might be involved in the pathogenesis of TGCT among occupationally exposed men. The combined use of JEM+SQ+EA seemed to limit misclassification by considering individual exposure variability and is, therefore, an appealing approach to assess occupational exposures in epidemiological studies.

Parental occupations at birth and risk of adult testicular germ cell tumors in offspring: a French nationwide case-control study

Background

Testicular germ cell tumors (TGCT) are the most frequent cancer in young men in developed countries. Parental occupational exposures during early-life periods are suspected to increase TGCT risk. The objective was to estimate the association between parental occupations at birth and adult TGCT.

Methods

A case-control study was conducted, including 454 TGCT cases aged 18-45 from 20 French university hospitals, matched to 670 controls based on region and year of birth. Data collected from participants included parental jobs at birth coded according to the International Standard Classification of Occupation-1968 and the French nomenclature of activities-1999. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors.

Results

Paternal jobs at birth as service workers (OR = 1.98, CI 1.18-3.30), protective service workers (OR = 2.40, CI 1.20-4.81), transport equipment operators (OR = 1.96, CI 1.14-3.37), specialized farmers (OR = 2.66, CI 1.03-6.90), and maternal jobs as secondary education teachers (OR = 2.27, CI 1.09-4.76) or in secondary education (OR = 2.35, CI 1.13-4.88) were significantly associated with adult TGCT. The risk of seminoma was increased for the above-mentioned paternal jobs and that of non-seminomas for public administration and defence; compulsory social security (OR = 1.99, CI 1.09-3.65); general, economic, and social administration (OR = 3.21, CI 1.23-8.39) for fathers; and secondary education teacher (OR = 4.67, CI 1.87-11.67) and secondary education (OR = 3.50, CI 1.36-9.01) for mothers.

Conclusion

Some paternal jobs, such as service workers, transport equipment operators, or specialized farmers, and maternal jobs in secondary education seem to be associated with an increased risk of TGCT with specific features depending on the histological type. These data allow hypotheses to be put forward for further studies as to the involvement of occupational exposures in the risk of developing TGCT, such as exposure to pesticides, solvents, or heavy metals.

Collective aeromedical evacuations of SARS-CoV-2-related ARDS patients in a military tactical plane: a retrospective descriptive study

After the appearance of the COVID-19 pandemic in France, MEROPE system was created to transform the military tactical ATLAS A400M aircraft into a flying intensive care unit. Collective aeromedical evacuations (aero-MEDEVAC) of patients suffering from SARS-CoV-2-related acute respiratory distress syndrome was performed from June to December 2020. A total of 22 patients were transported during seven missions. All aero-MEDEVAC was performed in safe conditions for patients and crew. No life-threatening conditions occurred during flight. Biohazard controls were applied according to French guidelines and prevented crew contamination. Thanks to rigorous selection criteria and continuous in-flight medical care, the safe transportation of these patients was possible. To the best of our knowledge, this is the first description of collective aero-MEDEVAC of these kinds of patients using a tactical military aircraft. We here describe the patient's characteristics and the flight's challenges.

Parental occupational exposure to solvents and risk of developing testicular germ cell tumors among sons: a French nationwide case-control study (TESTIS study)

OBJECTIVES

The etiology of testicular germ cell tumors (TGCT) is suspected to be related to prenatal environmental risk factors. Some solvents have potential endocrine disrupting or carcinogenic properties and may disrupt male genital development in utero. The aim of this study was to examine the association between parental occupational exposure to solvents and TGCT risk among their offspring.

METHODS

A French nationwide case-control study, TESTIS included 454 TGCT cases and 670 controls frequency-matched on region and 5-year age strata. Participants were interviewed via telephone and provided information on parental occupations at birth. Job-exposure matrices (JEM) developed in the French Matgéné program were used to assign exposure to five petroleum-based solvents, five solvents or groups of oxygenated solvents, and five chlorinated solvents. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors.

RESULTS

Occupational exposure to at least one solvent during the year of their son's birth was 41% among fathers and 21% among mothers. Paternal exposure to at least one solvent showed OR 0.89 (95% CI 0.68-1.15). Exposure to perchloroethylene (OR 1.41, 95% CI 0.55-3.61), methylene chloride (OR 1.13, 95% CI 0.54-2.34) and diesel/kerosene/fuel oil (OR 1.17, 95% CI 0.80-1.73) disclosed OR >1 but with low precision. Our results suggest a possible modest increase in non-seminoma risk for sons whose fathers were highly exposed to trichloroethylene (OR 1.44, 95% CI 0.79-2.63). Maternal exposure to at least one solvent showed OR 0.90 (95% CI 0.65-1.24). When stratifying by birth year, men born in the 1970s experienced an increased TGCT risk following maternal exposure to fuels and petroleum-based solvents (OR 2.74, 95% CI 1.11-6.76).

CONCLUSION

Overall, no solid association was found between parental occupational exposure to solvents and TGCT risk. The association found with maternal occupational exposure to fuels and petroleum solvents among older men needs further investigation.

Testicular germ cell tumour risk by occupation and industry: a French case-control study - TESTIS

OBJECTIVE

Testicular germ cell tumours (TGCT) are the most common cancer in men of working age and its incidence has increased notably over the past 40 years. Several occupations have been identified as potentially associated with TGCT risk. The aim of this study was to further explore the relationship between occupations, industries and TGCT risk in men aged 18-45 years.

METHODS

The TESTIS study is a multicenter case-control study conducted between January 2015 and April 2018 in 20 of 23 university hospital centers in metropolitan France. A total of 454 TGCT cases and 670 controls were included. Full job histories were collected. Occupations were coded according to the International Standard Classification of Occupation 1968 version (ISCO-1968) and industry according to the 1999 version of Nomenclature d'Activités Française (NAF-1999). For each job held, ORs and 95% CIs were estimated using conditional logistic regression.

RESULTS

A positive association was observed between TGCT and occupation as agricultural, animal husbandry worker (ISCO: 6-2; OR 1.71; 95% CI (1.02 to 2.82)), as well as salesman (ISCO: 4-51; OR 1.84; 95% CI (1.20 to 2.82)). An increased risk was further observed among electrical fitters and related, electrical and electronics workers employed for 2 years or more (ISCO: 8-5; OR≥2 years 1.83; 95% CI (1.01 to 3.32)). Analyses by industry supported these findings.

CONCLUSIONS

Our findings suggest that agricultural, electrical and electronics workers, and salesmen workers experience an increased risk of TGCT. Further research is needed to identify the agents or chemicals in these high-risk occupations which are relevant in the TGCT development.

TRIAL REGISTRATION NUMBER

NCT02109926.

Paternal Occupational Exposure to Heavy Metals and Welding Fumes and Testicular Germ Cell Tumours in Sons in France

Testicular cancer is the most common cancer in young men. Its causes are largely unknown, although prenatal occupational and environmental exposures have been suggested. We investigated paternal occupational exposure to heavy metals and welding fumes and the risk of testicular germ cell tumors (TGCT) in their offspring. A total of 454 cases and 670 controls were included from a French nationwide case-control study. The INTEROCC job exposure matrix was used to assign occupational exposures (cadmium, chromium, iron, nickel, lead, and welding fumes) to the fathers' jobs. Odds ratios (ORs) for TGCT were estimated using conditional logistic regression models for frequency-matched sets. Three complementary analytical approaches were used: (1) single-agent analysis, (2) analysis by groups, and (3) principal component analysis (PCA). The proportion of paternal exposure to different heavy metals and welding fumes ranged from 0.7% (cadmium) to 11.3% (lead). Based on PCA, three principal components explained 93.5% of the cumulative variance. No associations were found between heavy metals or welding fumes and TGCT. In this study, paternal occupational exposure to heavy metals or welding fumes was not associated with TGCT development in their sons.

Detection of a diastolic heart sound in children and young adults using high-frame-rate echocardiography

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Colin"s Kids, Inc. PO Box 93 Hopewell, NJ 08525

Introduction

The auscultatory finding of a fourth heart sound (S4) is clinically associated with a pathologic decrease in left ventricular compliance, but may be seen in healthy children by phonocardiography. High-frame-rate difference imaging (HFRDI) has demonstrated several propagating myocardial phenomena in the left ventricular (LV) lateral wall throughout the cardiac cycle, including during diastole. We hypothesize that these visualized wave phenomena correlate with physiologic and pathologic heart sounds.

Purpose

Using HFRDI, we sought to define the characteristics of a LV lateral wall late diastolic wave in healthy children and young adults.

Methods

HFRDI was obtained from the apical 4-chamber view with synchronized electrocardiogram (ECG) on the T5 system (Phased Array Research Scanner) acquiring images for this study between 587 and 1174 frames per second (depending on participant imaging characteristics). In addition, tissue Doppler images were acquired with synchronized ECG and phonocardiography (PCG) on a commercial ultrasound machine (Figure 1). Timing events were measured from the QRS onset on the ECG tracing. An S4 wave correlate was defined by meeting the following criteria: 1) occurring after the P wave on ECG; 2) at or after the onset of a’ on TDI; 3) occurring during the PCG S4; and 4) occurring prior to the S1 wave complex. The timing of the S4 wave in HFRDI was measured from the onset of QRS to the first appearance of the wave, and the wave velocity was calculated by measuring the length of the lateral wall and counting temporally calibrated image frames while the wave was visible.

Results

Nine healthy volunteers completed the imaging protocol with a median age of 20 years (range 6 – 22 years). A single, distinct late diastolic HFRDI wave was seen in all participants propagating from apex to base of the lateral LV free wall. This wave met the defined criteria to be a visual correlate of S4 in all participants. Measurements of correlated events are presented in Table 1. S4 propagating velocity was 2.96 ± 1.8 m/sec and occurred 25 ± 18 msec prior to the QRS onset. There is a strong positive correlation between age and S4 velocity [r(7) = 0.76, p = 0.019].

Conclusion

The S4 heart sound can be reliably visualized by high frame rate imaging and has similar characteristics in healthy children and young adults. Further definition of normal and abnormal S4 wave characteristics may lead to a novel tool in defining LV diastolic function. Abstract Table 1  Abstract Figure 1

Réponse à la vaccination contre le SARS-CoV-2 chez des patients hémodialysés chroniques

Introduction

Les patients hémodialysés chroniques (HDC) sont à haut risque de développer une forme grave d’infection à SARS-CoV-2. Ils constituent une population cible pour la vaccination. Toutefois, la réponse vaccinale chez ces patients n’est pas connue.

Matériels et méthodes

Étude observationnelle monocentrique portant sur l’ensemble des patients HDC à qui la vaccination contre la COVID-19 par le vaccin à ARNm BNT162b2 (Pfizer–BioNTech®) a été proposée. Deux injections ont été réalisées à 28 j d’intervalle, dans le bras opposé à l’abord vasculaire. Les données cliniques ont été recueillies prospectivement. La recherche d’anticorps spécifiques (IgG et IgM anti-protéine Spike) a été réalisée par immunochromatographie (COVID-19 BSS, Biosynex®) sur des sérums collectés avant la première injection, puis avant la seconde et 1 mois après. Les résultats sont exprimés en médiane [IQR : 25–75] ou %.

Résultats

Entre le 15 janvier et le 21 mars 2021, la vaccination a été proposée aux 55 patients du centre et acceptée par 49 (89,1 %) patients, les 6 autres ayant refusé. Parmi les 49 patients vaccinés, l’âge médian est de 70 [63–82,5] ans, 17 (34,7 %) sont diabétiques, et 8 (16,3 %) ont une greffe d’organe solide. La durée médiane en dialyse à la vaccination est de 26,2 [17,8–49,9] mois ; les patients sont dialysés sur une membrane en polysulfone (PSF), sauf 4 (8,2 %) sur une membrane en polyméthylmétacrylate (PMMA).

La séroprévalence en IgG à j0 est de 12,2 % (6/49 patients, dont 4 ayant un antécédent de COVID symptomatique de plus de 3 mois, avec PCR positive). Parmi les 43 patients séronégatifs à l’inclusion, 10 sont encore en cours de vaccination. Les 33 patients ayant complété le schéma vaccinal ont les résultats suivants, respectivement avant la seconde injection et 1 mois après : IgM, 9,1 % (3 patients) et 12,1 % (4 patients) ; IgG, 9,1 % (3 patients) et 87,9 % (29 patients).

Tous les patients positifs en IgM le sont également en IgG (aucun n’a développé de signes cliniques évocateurs de COVID-19 dans le suivi). Parmi les 4 patients non répondeurs, 1 recevait une immunothérapie pour cancer cutané, et tous ont une membrane en PSF. Tous les patients transplantés d’organe ont eu une réponse vaccinale positive 1 mois après la seconde injection. Le profil sérologique des patients dialysés avec un filtre en PMMA est comparable à ceux avec un filtre en PSF. La tolérance est bonne: 1 patiente a présenté une réponse systémique avec fièvre et frisson, et 60,1 % ont eu une réaction douloureuse au point d’injection ayant duré 24 h.

Conclusion

L’acceptation et la réponse vaccinale au vaccin à ARNm contre la COVID-19 sont bonnes chez les patients HDC.

[The role of electromagnetic navigation bronchoscopy in the diagnosis of peripheral pulmonary lesions]

INTRODUCTION

Electromagnetic navigation bronchoscopy (ENB) is a recent, minimally invasive procedure utilized to guide endoscopic diagnostic tools to peripheral pulmonary nodules. The place of this technology among other diagnostic procedures remains uncertain.

METHOD

We analyzed our 30 first months of ENB used in the diagnosis of 106 lesions in 101 patients, from June 2016 to December 2018. Follow-up and final diagnosis was completed for 95 lesions (90%).

RESULTS

ENB was performed for 3.5% of all patients referred for abnormal findings on pulmonary imaging, and represented 19% of second line procedures for peripheral pulmonary lesions. Procedures were performed under general anesthesia, with a mean duration of 35min. The sensitivity of ENB was 64% (95%CI: 52-74%) for lesions with a mean diameter of 21mm, with an improvement over time (sensitivity 69% in the last 18 months). The presence of a bronchus within the lesion (bronchus sign) was associated with an increased sensitivity of 74%. Pneumothorax occurred in 5 patients (5%) of which 4 required drainage. There was no hemoptysis, and no death related to the procedure.

CONCLUSION

ENB is a minimally invasive procedure reaching acceptable sensitivity in the most difficult patients. ENB can be recommended for the diagnosis of peripheral pulmonary nodules when no other procedure is successful or possible. Its use as a first choice procedure is, for the moment, limited by the cost, but must be weighed against that of non-diagnostic procedures, and the cost of complications of trans-thoracic lung biopsies.

Oxaliplatin, 5-Fluorouracil and Nab-paclitaxel as perioperative regimen in patients with resectable gastric adenocarcinoma: A GERCOR phase II study (FOXAGAST)

BACKGROUND

5-Fluorouracil (5-FU) and platinum-based perioperative chemotherapy is standard of care for resectable gastric adenocarcinoma (RGA). Nanoparticle albumin-bound (Nab-) paclitaxel is active in advanced disease but has never been evaluated in the perioperative setting. The objective was to evaluate the efficacy of Nab-paclitaxel in combination with FOLFOX for RGA patients.

METHODS

We performed a non-randomised, open-label, phase II study. RGA patients were assigned to receive neoadjuvant Nab-paclitaxel (150 mg/m²) and FOLFOX q2w for six cycles. Six additional post-operative cycles were kept at the investigator's discretion. The primary end-point was complete pathological response (tumour regression grade [TRG1]) rate. According to Fleming design, 49 patients were required to test H₀ (10% TRG1) and H₁ (25% TRG1). To reject H₀, TRG1 had to be achieved in 8 patients.

RESULTS

Forty-nine patients were included. Median number of neoadjuvant chemotherapy cycles was 6 (range, 3-6). Median dose intensity for Nab-paclitaxel, oxaliplatin and 5-FU was 96% (38-103%), 97% (47-103%) and 99% (50-112%), respectively. Surgery could not be performed in 5 (10.2%) patients. Tumour resection was R0 for 42 of 44 (95.5%) patients. Pathological review classified tumours as TRG1 to TRG5 for 8 (16.3%), 11 (22.5%), 4 (8.2%), 18 (36.7%) and 3 (6.1%) patients, respectively. Grade 3 or worse toxicities during neoadjuvant chemotherapy were non-febrile neutropenia (20.4%), nausea (8.2%), diarrhoea (8.2%) and neuropathy (6.1%). Of 44 patients, 14 (31.8%) experienced surgery-related complications and three (6.8%) died of surgical complications.

CONCLUSION

This regimen shows promising activity. Toxicity is manageable but a meaningful rate of surgical complications was observed. This strategy deserves investigation in phase III studies.

Antidiarrheal Action of Bacillus subtilis CU1 CNCM I-2745 and Lactobacillus plantarum CNCM I-4547 in Mice

Preventive actions of probiotics as antidiarrheal agents are well documented, but their mechanisms are poorly understood. Two selected probiotics, Bacillus subtilis CU1 and Lactobacillus plantarum CNCM I-4547, were tested in mouse experimental models of diarrhea and the possible mechanisms of action were investigated. Diarrhea was induced in mice by oral castor oil administration or by i.v. injection of lipopolysaccharide (LPS) of Salmonella enteritis. The antidiarrheal drug loperamide was used as control. Fecal water excretion was quantified for 2 h and paracellular permeability and electrical parameters of the colon were assessed in Ussing chambers. The expression of colonic exchangers or channels and of Toll-like receptor 4 (TLR4) was assessed by immunohistochemistry. Prophylactic treatment with B. subtilis CU1 or with L. plantarum CNCM I-4547 reduced LPS-induced diarrhea. The reduction of water excretion was in the same range as those induced by loperamide. In the castor oil model, this effect was only observed with B. subtilis CU1. The two probiotic treatments abolished the increase in paracellular permeability induced by LPS, but not by castor oil. However, only L. plantarum CNCM I-4547 treatment decreased the colonic expression of TLR-4. After B. subtilis CU1, colonic expression of cystic fibrosis transmembrane conductance regulator (CFTR) was reduced and that of Na⁺/H⁺ exchanger 3 (NHE3) increased. B. subtilis CU1 may increase the capacity of the colon to absorb excess of water in diarrheic conditions by acting on CFTR and NHE3 expression. The two probiotics strains showed an impact on diarrhea through limitation of water excretion that may involve paracellular permeability or electrolyte transport for L. plantarum CNCM I-4547 and B. subtilis CU1 respectively.

[Oncologic and perioperative outcomes of robot-assisted radical cystectomy: A single-center prospective series]

INTRODUCTION

The aim of this study was to report perioperative and oncological outcomes of robot-assisted radical cystectomy (RARC) in a single-center series and to evaluate the impact of the experience on perioperative outcomes.

METHODS

Between March 2012 and January 2016, 41 patients underwent RARC associated with extended pelvic lymphadenectomy for muscle-invasive bladder cancer. All RARC included were performed by a single-surgeon in one center. Perioperative and oncological datas were collected prospectively. Recurrence-free (RFS), overall (OS) and cancer-specific survivals (CSS) were estimated using the Kaplan-Meier Method. The impact of the experience on perioperative data was estimated using Spearman's correlation test.

RESULTS

Mean age was 67,7years (±10.6). Most patients underwent neoadjuvant chemotherapy (73.2%). Mean operative time and mean estimated blood loss were respectively 319.5minutes (±85.3) and 662.5mL (±360.9). Eight patients needed perioperative blood transfusion (19.5%). Conversion to open surgery was necessary in 3 cases (7.3%). Ileal neobladder was performed in 26.8% of the cases (54.5% being performed intracorporeal), and non-continent urinary diversion in 73.2%. Mean nodal yield was 17.7 (±9.3). Positive surgical margins were observed in 1 patient (2.3%). Mean length of stay was 13.2 days (±9.8). Postoperative complication rate was 46,3%. After a median follow-up of 16months, estimated 2 year-OS and CSS were respectively 62 and 76.1%. Estimated 2-year RFS was 67.6%. Perioperative outcomes improved with experience with a significant decrease in operative time (P=0.04) and a significant increase of nodal yield (P=0.05).

CONCLUSION

In this single-center prospective study, satisfactory perioperative and oncological outcomes after RARC were observed despite the learning curve. Perioperative outcomes improved with surgeon's experience. Further studies are needed to confirm these findings.

LEVEL OF EVIDENCE

4.

Probiotic strain Bacillus subtilis CU1 stimulates immune system of elderly during common infectious disease period: a randomized, double-blind placebo-controlled study

Background

Bacillus probiotics health benefits have been until now quite poorly studied in the elderly population. This study aimed to assess the effects of Bacillus subtilis CU1 consumption on immune stimulation and resistance to common infectious disease (CID) episodes in healthy free-living seniors.

Results

One hundred subjects aged 60–74 were included in this randomized, double-blind, placebo-controlled, parallel-arms study. Subjects consumed either the placebo or the probiotic (2.10⁹B. subtilis CU1 spores daily) by short periodical courses of 10 days intermittently, alternating 18-day course of break. This scheme was repeated 4 times during the study. Symptoms of gastrointestinal and upper/lower respiratory tract infections were recorded daily by the subjects throughout the study (4 months). Blood, saliva and stool samples were collected in a predefined subset of the first forty-four subjects enrolled in the study. B. subtilis CU1 supplementation did not statistically significantly decrease the mean number of days of reported CID symptoms over the 4-month of study (probiotic group: 5.1 (7.0) d, placebo group: 6.6 (7.3) d, P = 0.2015). However, in the subset of forty-four randomized subjects providing biological samples, we showed that consumption of B. subtilis CU1 significantly increased fecal and salivary secretory IgA concentrations compared to the placebo. A post-hoc analysis on this subset showed a decreased frequency of respiratory infections in the probiotc group compared to the placebo group.

Conclusion

Taken together, our study provides evidence that B. subtilis CU1 supplementation during the winter period may be a safe effective way to stimulate immune responses in elderly subjects.

Does the rectus femoris nerve block improve knee recurvatum in adult stroke patients? A kinematic and electromyographic study

Knee recurvatum (KR) during gait is common in hemiplegic patients. Quadriceps spasticity has been postulated as a cause of KR in this population. The aim of this study was to assess the role of rectus femoris spasticity in KR by using selective motor nerve blocks of the rectus femoris nerve in hemiparetic stroke patients. The data from six adult, post-stroke hemiplegic patients who underwent a rectus femoris nerve block for a stiff-knee gait were retrospectively analyzed. An extensive clinical and functional evaluation was performed and gait was assessed by motion analysis (kinematic, kinetic and electromyographic parameters) before and during the block realized using 2% lidocaine injected under a neurostimulation and ultrasonographic targeting procedure. The main outcome measures were the peak knee extension in stance and peak knee extensor moment obtained during gait analysis. No serious adverse effect of the nerve block was observed. The block allowed a reduction of rectus femoris overactivity in all patients. Peak knee extension and extensor moment in stance did not improve in any patient, but peak knee flexion during the swing phase was significantly higher after block (mean: 31.2° post, 26.4 pre, p < 0.05). Our results provide arguments against the hypothesis that the spasticity of the rectus femoris contributes to KR.

Solar irradiance in clear atmosphere: study of parameterisations of change with altitude

Abstract. Parameterisation of changes of the solar irradiance at ground level with a specific variable (e.g. solar zenithal angle, aerosol optical depth, altitude, etc.) is often used in operational processes because it saves computational time. This paper deals with the modelling of the vertical profile of downwelling solar irradiance for the first two kilometres above ground in clear sky conditions. Two analytical parameterisations are evaluated for direct and global irradiance in spectral bands as well as for the total irradiance. These parameterisations reproduce the vertical profile with good accuracy for global spectral irradiance and are less accurate for direct component, especially in turbid atmosphere. A piecewise linear interpolation technique using irradiance values known at surface and 4 altitudes every 500 m performs better in any case.

Investigation and management of an imipenem-resistant oxa-23 Acinetobacter baumannii outbreak in an intensive care unit

OBJECTIVES

The study objectives were to describe the investigation and management of an imipenem-resistant Acinetobacter baumannii outbreak that occurred in the 15-bed ICU of a tertiary care teaching hospital (Brest, France), during the summer 2008.

PATIENTS AND METHODS

Patients harboring an imipenem-resistant A. baumannii strain were defined as case patients. We described case occurrence and steps taken to control the outbreak: contact isolation, reinforcement of hygiene procedures, unit shutdown decision, unit disinfection, and reopening. We also made a case control study and a cost analysis of the outbreak management.

RESULTS

During a 10-day period, five patients were positive for a single clone of imipenem-resistant oxa-23 A. baumannii. Four patients presented with ventilation-acquired pneumonia and one was asymptomatic. The first two patients died one day after the first swab which led to the identification of A. baumannii. No additional case was noted in the ICU or in other hospital units after deciding to close the ICU. The cost of outbreak management was estimated at 264,553 euros. The case control study identified several factors associated with infection or colonization: length of stay in the ICU, chronic respiratory disease, number of previous antibiotic classes used, duration of ventilation, prone position, echocardiography, and presence of a nasogastric tube.

CONCLUSION

This outbreak occurred during the summer period requiring the shutdown of the ICU and inducing a considerable cost. Rapid reactions of the ICU staff during the outbreak enabled to limit the epidemic.