Didier Che

A Community-Wide Outbreak of Legionnaires Disease Linked to Industrial Cooling Towers—How Far Can Contaminated Aerosols Spread?

A community-wide outbreak of legionnaires disease occurred in Pas-de-Calais, France, in November 2003-January 2004. Eighteen (21%) of 86 laboratory-confirmed cases were fatal. A case-control study identified smoking, silicosis, and spending >100 min outdoors daily as risk factors for acquiring the disease. Legionella pneumophila strain Lens was isolated from cooling towers, wastewater, and air samples from plant A. This unique strain matched all 23 clinical isolates, as assessed by pulsed-field gel electrophoresis subtyping. Modeling of atmospheric dispersion of aerosols emitted from plant A cooling towers showed good coverage of the communes where patients lived and showed that the dispersion extended over a distance of at least 6 km from plant A. No other aerosol-producing installation was identified as a plausible source, and no common source of indoor exposure was found. These findings implicate plant A as the most likely outbreak source and suggest that the distance of airborne transmission of L. pneumophila may be greater than previously reported.

Population-Based Analysis of Invasive Fungal Infections, France, 2001–2010

These infections are underrecognized as a cause of death in the general population and high-risk groups.

Antimicrobial Resistance in Commensal Flora of Pig Farmers

We assessed the quantitative contribution of pig farming to antimicrobial resistance in the commensal flora of pig farmers by comparing 113 healthy pig farmers from the major French porcine production areas to 113 nonfarmers, each matched for sex, age, and county of residence. All reported that they had not taken antiimicrobial agents within the previous month. Throat, nasal, and fecal swabs were screened for resistant microorganisms on agar containing selected antimicrobial agents. Nasopharyngeal carriage of Staphylococcus aureus was significantly more frequent in pig farmers, as was macrolide resistance of S. aureus from carriers. Nongroupable streptococci from the throat were more resistant to the penicillins in pig farmers. The intestinal isolation of enterococci resistant to erythromycin or vancomycin was not significantly higher in pig farmers in contrast to that of enterobacteria resistant to nalidixic acid, chloramphenicol, tetracycline, and streptomycin. Prevalence of resistance in predominant fecal enterobacteria was also significantly higher in pig farmers for cotrimoxazole, tetracycline, streptomycin, and nalidixic acid. We determined a significant association between pig farming and isolation of resistant commensal bacteria.

Introduction of SARS in France, March–April, 2003

We describe severe acute respiratory syndrome (SARS) in France. Patients meeting the World Health Organization definition of a suspected case underwent a clinical, radiologic, and biologic assessment at the closest university-affiliated infectious disease ward. Suspected cases were immediately reported to the Institut de Veille Sanitaire. Probable case-patients were isolated, their contacts quarantined at home, and were followed for 10 days after exposure. Five probable cases occurred from March through April 2003; four were confirmed as SARS coronavirus by reverse transcription–polymerase chain reaction, serologic testing, or both. The index case-patient (patient A), who had worked in the French hospital of Hanoi, Vietnam, was the most probable source of transmission for the three other confirmed cases; two had been exposed to patient A while on the Hanoi-Paris flight of March 22–23. Timely detection, isolation of probable cases, and quarantine of their contacts appear to have been effective in preventing the secondary spread of SARS in France.

Factors associated with hospital mortality in community-acquired legionellosis in France

The aims of this study were to describe the clinical, biological and radiological features of community-acquired (CA) Legionnaires’ disease (LD) and identify the predictors of mortality in hospitalised patients. Demographic data, risk factors, clinical and biological features, medical management, complications, and outcome from 540 hospitalised patients with confirmed CA LD were prospectively recorded. 8.1% of patients (44 out of 540) died. The predictors of survival after Kaplan–Meier analysis were male sex (p=0.01), age <60 yrs (p=0.02), general symptoms (p=0.006), intensive care unit (ICU) stay (p<0.001), and class II–III Pneumonia Severity Index score (p=0.004). Six predictors of death were identified by multivariate analysis: age (per 10-yr increment) (relative hazard (RH) 1.50, 95% CI 1.21–1.87), female sex (RH 2.00, 95% CI 1.08–3.69), ICU admission (RH 3.31, 95% CI 1.67–6.56), renal failure (RH 2.73, 95% CI 1.42–5.27), corticosteroid therapy (RH 2.54, 95% CI 1.04–6.20) and C-reactive protein (CRP) >500 mg·L−1 (RH 2.14, 95% CI 1.02–4.48). Appropriate antibiotic therapy was prescribed for 70.8% (292 out of 412) of patients after admission and for 99.8% (537 out of 538) of patients after diagnosis confirmation. In conclusion, female sex, age, ICU stay, renal failure, corticosteroid treatment and increased level of CRP are significant risk factors for mortality in CA LD.

Association between indicators of cattle density and incidence of paediatric haemolytic – uraemic syndrome (HUS) in children under 15 years of age in France between 1996 and 2001: an ecological study

Over the past years Shiga-like toxin-producing Escherichia coli (STEC) O157:H7 emerged as an important cause of severe gastrointestinal illnesses and haemolytic-uraemic syndrome (HUS) with up to 10% of children infected with STEC developing HUS. We conducted a geographical ecological study using the district as the statistical unit. For each district, we estimated the incidence of HUS among children <15 years for the period 1996-2001 from national HUS surveillance data and data obtained on cattle density. We used multivariate Poisson regression to quantify the relation, adjusted for covariates, between paediatric HUS incidence and exposure to cattle. In univariate analysis, a positive association was observed between several cattle-density indicators and HUS incidence. In multivariate analysis, HUS paediatric incidence was associated with dairy cattle density and the ratio of calves to children <15 years (P<0.001). Our findings are consistent with previous studies in other countries and support the recommendation to limit exposure of children to dairy cattle and manure to reduce the risk of STEC infection.

Bronchiolite aiguë du nourrisson en France : bilan des cas hospitalisés en 2009 et facteurs de létalité

Little information is available on the characteristics of infants hospitalized for acute bronchiolitis in France. An analysis of hospital records (PMSI) was conducted at the national level to describe the cases of bronchiolitis that require hospitalization among infants under 1 year of age and the factors associated with death. The analysis of all admissions that occurred during 2009, for which the diagnosis of acute bronchiolitis was recorded in the PMSI database for infants aged less than 1 year, was performed. Cases were described according to age, sex, underlying conditions (including bronchopulmonary dysplasia, cystic fibrosis, and congenital heart disease), length of hospital stay, recurrent admissions, admission to an intensive care unit (ICU), and use of assisted ventilation. Factors associated with death during hospitalization were studied by logistic regression. The hospitalization rate was 35.8 per 1000 infants under 1 year in 2009 in France. Approximately 10% of hospitalized infants required ICU admission. Twenty-two infants died. The estimated case-fatality rate was 0.08% among hospitalized infants and 0.56% for those hospitalized in the ICU. Mortality among all infants under 1 year was 2.6/10(5) in France. Factors associated with death were bronchopulmonary dysplasia (OR=6.7, 95% CI [1.5-29.8]), hospitalization in an ICU (OR=6.46, 95% CI [2.4-17.4]), and the use of assisted ventilation (OR=6.2, 95% CI [2.2-17.1]). This study has enabled the quantification of the rate of hospitalization and mortality, and a better description of infants who need hospitalization. The results are consistent with international literature, but further prospective analysis will be needed to better describe the cases at higher risk, aiming to improve their management.

Host-related risk factors and clinical features of community-acquired legionnaires disease due to the Paris and Lorraine endemic strains, 1998-2007, France.

BACKGROUND In France, Legionnaires disease is mainly caused by Legionella pneumophila. Here, we investigated possible host factors associated with susceptibility to community-acquired Legionnaires disease caused by the endemic Paris and Lorraine strains. METHODS We conducted a double-nested exploratory case-control study with use of data from the French national surveillance network of incident Legionnaires disease cases notified from 1998 through 2007. Patients with community-acquired Legionnaires disease and an L. pneumophila serogroup 1 isolate were eligible. Case patients were patients infected by the Paris or Lorraine strain, and control patients were those infected by sporadic strains. Epidemiological and clinical factors associated with infection with the Paris and Lorraine strains were assessed by calculating adjusted odds ratios (aOR) in multivariate logistic regression models. RESULTS We studied 1090 patients infected by sporadic strains (n = 920), the Paris strain (n = 80), or the Lorraine strain (n = 90). Infection with the Paris strain was significantly associated with female sex (aOR, 1.98; 95% confidence interval [CI], 1.19-3.28), steroid therapy (aOR, 3.16; 95% CI, 1.76-5.68), and a history of cancer or hematologic malignancies (aOR, 2.08; 95% CI, 1.15-3.76). In addition, the mortality rate was higher among patients infected with the Paris strain than in the control group (38% vs. 25.5%). The Lorraine strain was associated with smoking (aOR, 1.82; 95% CI, 1.14-2.91) and reduced mortality (9.9%). . CONCLUSION Several host characteristics were associated with the risk of infection by endemic strains of L. pneumophila serogroup 1. These findings may help to guide preventive measures. Factors predisposing patients to infection by specific strains need to be explored further.

Epidemiologic characteristics associated with ST23 clones compared to ST1 and ST47 clones of Legionnaires disease cases in France

In France, approximately 1200 cases of Legionnaires disease (LD) are reported annually, and isolates are available for approximately 20% of cases identified since 2000. All Legionella pneumophila serogroup 1 (sg1) isolates are characterized by sequence-based typing at the National Reference Centre. LD cases caused by L. pneumophila sg1 reported from 2008 through 2012 were considered for the study. Our study objective was to describe cases according to their sequence type (ST). We also constructed multivariable modified Poisson regression models to estimate the incidence rate ratio (IRR) and to identify characteristics potentially associated with ST23 clones compared to ST1 and ST47 clones. We studied 1192 patients infected by ST1 (n = 109), ST23 (n = 236), ST47 (n = 123) or other STs (n = 724). The geographic distribution of the ST23 cases across the country was significantly different compared to other ST groups. This genotype was significantly associated with the absence of corticosteroid therapy compared to ST1 (IRR = 0.56; p 0.016). Concerning exposure, the ST23 genotype was significantly less associated with hospital-acquired infections compared to ST1 (IRR = 0.32; p 0.001), but it was more associated with infections acquired in hospitals and elderly settings compared with ST47. Finally, the ST23 genotype was less frequently associated with travel than other STs. Despite the large number of cases of ST23 infection, we did not identify any characteristics specific to this ST. However, we identified independent associations between ST1 and nosocomial transmission and steroid therapy. These findings should encourage further exploration, especially in terms of environmental diffusion, strain virulence and host factors.

Situation épidémiologique de la tuberculose en Ile-de-France en 2001.

Resume Introduction En France, l’incidence de la tuberculose est stable autour de 10 cas pour 100 000 habitants depuis 1997. Cependant, l’Ile-de-France, ou la densite de population et le nombre de personnes en situation precaire sont les plus importants, comptabilise a elle seule plus de la moitie des cas declares en France. Methodes Etude descriptive retrospective a partir des donnees de la declaration obligatoire pour l’annee 2001. Resultats L’incidence de la tuberculose etait de 27,2 cas pour 100 000 habitants en 2001 en Ile-de-France et de 48,4 pour 100 000 habitants a Paris. Les sujets les plus touches etaient les sujets jeunes de nationalite etrangere, notamment d’un pays d’Afrique sub-saharienne. Les formes pulmonaires etaient majoritaires et touchaient 72 % des sujets. Une co-infection par le VIH etait documentee pour 7,5 % des sujets. Une demande d’intervention des services de lutte anti-tuberculeuse etait demandee dans moins de 30 % des cas, et pour seulement 50 % des cas vivant en collectivite et ayant une localisation pulmonaire. Conclusion La surveillance epidemiologique ainsi que la lutte anti-tuberculeuse necessitent d’etre renforcee en Ile-de-France, notamment par la mobilisation de l’ensemble des intervenants afin d’ameliorer la reactivite et l’efficacite du dispositif.