Detection of highly macrolide-resistant Legionella pneumophila strains from a hotel water network using systematic whole-genome sequencing.

OBJECTIVES: Implementation of an antibiotic resistance detection tool in Legionella daily surveillance at the French National Reference Centre for Legionella. METHODS: Systematic WGS of Legionella pneumophila isolates and bioinformatics detection of specific mutations linked to antibiotic resistance. Phenotypic validation of antibiotic resistance detected by WGS was performed by the broth microdilution method. RESULTS: More than 3000 L. pneumophila strains were screened for antibiotic resistance. A macrolide resistance-associated A2052G mutation in the 23S rRNA gene was identified in the genome of eight isolates from a hotel water network. High-level macrolide resistance (i.e. MICs of 1024-2048 mg/L for azithromycin and erythromycin) with no cross-resistance to other antimicrobials was phenotypically confirmed by antimicrobial susceptibility testing for the eight isolates. CONCLUSIONS: Systematic WGS of L. pneumophila is a powerful tool for first-line high-throughput screening of antibiotic resistance before phenotypic validation.

A Community Outbreak of Legionnaires' Disease with Two Strains of L. pneumophila Serogroup 1 Linked to an Aquatic Therapy Centre.

An outbreak of Legionnaires' disease affected 18 people in Montpellier, a town of the south of France, between December 2016 and July 2017. All cases were diagnosed by a positive urinary antigen test. No deaths were reported. Epidemiological, environmental and genomic investigations (nested Sequence-Based Typing (nSBT) and whole genome sequencing) were undertaken. For the cases for which we had information, four had a new isolate (ST2471), one had a different new isolate (ST2470), one had a genomic pattern compatible with the ST2471 identified by nSBT (flaA = 3), and one had a genomic pattern not compatible with two previous identified STs (pilE = 6). The analysis conducted on the pool of an aquatic therapy center revealed seven isolates of Legionella pneumophila. Whole genome analysis confirmed the link between the environmental and clinical isolates for both ST2470 and ST2471. As the outbreak occurred slowly, with several weeks between new cases, it was not possible to immediately identify a common source. The sixth case was the first to report having aquatic therapy care. Of the 18 cases, eight had attended the aquatic therapy center and the other 10 were inhabitants who lived, worked or walked close to the center. The main cause for this outbreak was the lack of facility maintenance. This investigation highlights the risk to public health of aquatic therapy centers for users and nearby populations, and emphasizes the need for risk reduction measures with specific guidelines to improve health and safety in aquatic facilities.

Co-infection with Legionella and SARS-CoV-2, France, March 2020.

We describe a March 2020 co-occurrence of Legionnaires' disease (LD) and coronavirus disease in France. Severe acute respiratory syndrome coronavirus 2 co-infections were identified in 7 of 49 patients from LD case notifications. Most were elderly men with underlying conditions who had contracted severe pneumonia, illustrating the relevance of co-infection screening.

Underdetection of cases of COVID-19 in France threatens epidemic control.

As countries in Europe gradually relaxed lockdown restrictions after the first wave, test-trace-isolate strategies became critical to maintain the incidence of coronavirus disease 2019 (COVID-19) at low levels1,2. Reviewing their shortcomings can provide elements to consider in light of the second wave that is currently underway in Europe. Here we estimate the rate of detection of symptomatic cases of COVID-19 in France after lockdown through the use of virological3 and participatory syndromic4 surveillance data coupled with mathematical transmission models calibrated to regional hospitalizations2. Our findings indicate that around 90,000 symptomatic infections, corresponding to 9 out 10 cases, were not ascertained by the surveillance system in the first 7 weeks after lockdown from 11 May to 28 June 2020, although the test positivity rate did not exceed the 5% recommendation of the World Health Organization (WHO)5. The median detection rate increased from 7% (95% confidence interval, 6-8%) to 38% (35-44%) over time, with large regional variations, owing to a strengthening of the system as well as a decrease in epidemic activity. According to participatory surveillance data, only 31% of individuals with COVID-19-like symptoms consulted a doctor in the study period. This suggests that large numbers of symptomatic cases of COVID-19 did not seek medical advice despite recommendations, as confirmed by serological studies6,7. Encouraging awareness and same-day healthcare-seeking behaviour of suspected cases of COVID-19 is critical to improve detection. However, the capacity of the system remained insufficient even at the low epidemic activity achieved after lockdown, and was predicted to deteriorate rapidly with increasing incidence of COVID-19 cases. Substantially more aggressive, targeted and efficient testing with easier access is required to act as a tool to control the COVID-19 pandemic. The testing strategy will be critical to enable partial lifting of the current restrictive measures in Europe and to avoid a third wave.

Transmission of Legionnaires' Disease through Toilet Flushing.

We describe 2 cases of healthcare-associated Legionnaires' disease in patients in France hospitalized 5 months apart in the same room. Whole-genome sequencing analyses showed that clinical isolates from the patients and isolates from the room's toilet clustered together. Toilet contamination by Legionella pneumophila could lead to a risk for exposure through flushing.

First cases of coronavirus disease 2019 (COVID-19) in the WHO European Region, 24 January to 21 February 2020.

In the WHO European Region, COVID-19 surveillance was implemented 27 January 2020. We detail the first European cases. As at 21 February, nine European countries reported 47 cases. Among 38 cases studied, 21 were linked to two clusters in Germany and France, 14 were infected in China. Median case age was 42 years; 25 were male. Late detection of the clusters' index cases delayed isolation of further local cases. As at 5 March, there were 4,250 cases.

First cases of coronavirus disease 2019 (COVID-19) in France: surveillance, investigations and control measures, January 2020.

A novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) causing a cluster of respiratory infections (coronavirus disease 2019, COVID-19) in Wuhan, China, was identified on 7 January 2020. The epidemic quickly disseminated from Wuhan and as at 12 February 2020, 45,179 cases have been confirmed in 25 countries, including 1,116 deaths. Strengthened surveillance was implemented in France on 10 January 2020 in order to identify imported cases early and prevent secondary transmission. Three categories of risk exposure and follow-up procedure were defined for contacts. Three cases of COVID-19 were confirmed on 24 January, the first cases in Europe. Contact tracing was immediately initiated. Five contacts were evaluated as at low risk of exposure and 18 at moderate/high risk. As at 12 February 2020, two cases have been discharged and the third one remains symptomatic with a persistent cough, and no secondary transmission has been identified. Effective collaboration between all parties involved in the surveillance and response to emerging threats is required to detect imported cases early and to implement adequate control measures.

Progress in the surveillance and control of Legionella infection in France, 1998-2008.

BACKGROUND: In France, the notification of Legionnaires' disease (LD) has been mandatory since 1987. Following a study showing an important under-reporting of the disease, the surveillance system was strengthened in 1997: the urinary antigen detection test was introduced as a new diagnostic tool and guidelines for prevention and control of the disease were implemented. After these measures, the incidence of LD increased gradually, reaching 2.5 per 100,000 in 2005, and then slightly decreased (2.0 per 100,000 in 2008). METHODS: Data from the mandatory notification system and from the national reference centre for Legionella were analysed. Analysis covered the 1998-2008 period. RESULTS: During the period 1998-2008 a total of 11147 cases of LD were reported in France through the mandatory system. The majority of cases were diagnosed by urinary antigen test. The median age of cases was 61 years, the male to female ratio was 2.9, and the case fatality rate was 13%. Exposure during travel was documented for 17% of cases. A hospital-acquired infection was suspected for 9% of cases, and this percentage decreased from 21% in 1998 to 7% in 2008. Over this period, 14 community outbreaks were identified involving 380 cases, and cooling towers were the most probable source of infection for 13. No outbreak was reported in 2008. Registration at the regional level of all cooling towers became mandatory at the end of 2004, and the 1997 prevention and control guidelines were updated in 2005. In recent years, several regulations have also been implemented in the hospital setting and care homes for the elderly. CONCLUSION: All these measures have contributed to strengthen the French surveillance system and improve our ability to better prevent, detect, and control LD.

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.

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.

Past excessive alcohol consumption: a major determinant of severe liver disease among newly referred hepatitis C virus infected patients in hepatology reference centers, France, 2001.

PURPOSE: Our study aimed to identify factors associated with the occurrence of severe liver disease in hepatitis C virus (HCV) positive patients at first referral to hepatology reference centers in France in 2001. METHODS: Patients reported through the national hospital-based hepatitis C surveillance system in 2001 were included. The definition of severe liver disease was based on clinical, biological, and morphological evaluation; cirrhosis (+/- complication) and primary liver cancer were classified as severe liver disease. Patient characteristics were compared for those with and without severe liver disease. RESULTS: Of the 3404 newly referred patients in the 26 participating centers, 391 (11.5%) had severe liver disease. Male gender (adjusted odds ratios [aOR]=1.4; 95% confidence interval [CI], 1.0-1.9), age over 39 years at referral (aOR=3.8; 95% CI, 2.7-5.3), past excessive alcohol consumption (aOR=2.6; 95% CI, 1.9-3.5), and HIV seropositivity (aOR=1.9; 95% CI, 1.1-3.3) were each independently associated with an increased risk of severe liver disease. In the subgroup of patients with known age at time of HCV exposure, age over 39 years at time of exposure (aOR=1.6; 95% CI, 1.1-2.4), duration of HCV infection over 15 years (aOR=2.6; 95% CI, 1.8-3.7), known HBs antigen positivity (aOR=2.4; 95% CI, 1.1-5.2), and past excessive alcohol consumption (aOR=2.7; 95% CI, 1.8-3.9) were each associated with increased risk of severe liver disease. CONCLUSIONS: Our findings underscore the important role of past excessive alcohol consumption on the development of severe liver disease for HCV patients.

Risk factors for leptospirosis in metropolitan France: results of a national case-control study, 1999-2000.

Risk factors for leptospirosis in France were investigated to improve the vaccination program for this disease. Data from 90 hospitalized case patients and 169 matched control subjects were analyzed in a case-control study. Skin lesions, canoeing, contact with wild rodents, and country residence were independently associated with leptospirosis, emphasizing that leisure activity is a risk factor for this illness.

Legionella pneumophila serogroup 1 strain Paris: endemic distribution throughout France.

An analysis of 691 French clinical Legionella isolates showed that the endemic L. pneumophila serogroup 1 strain Paris was responsible for 12.2% of all cases of legionellosis and had a specific pulsed-field gel electrophoresis pattern. We also demonstrated the presence of this endemic clone throughout Europe.