A comparison of COVID-19 incidence rates across six European countries in 2021.

International comparisons of COVID-19 incidence rates have helped gain insights into the characteristics of the disease, benchmark disease impact, shape public health measures and inform potential travel restrictions and border control measures. However, these comparisons may be biased by differences in COVID-19 surveillance systems and approaches to reporting in each country. To better understand these differences and their impact on incidence comparisons, we collected data on surveillance systems from six European countries: Belgium, England, France, Italy, Romania and Sweden. Data collected included: target testing populations, access to testing, case definitions, data entry and management and statistical approaches to incidence calculation. Average testing, incidence and contextual data were also collected. Data represented the surveillance systems as they were in mid-May 2021. Overall, important differences between surveillance systems were detected. Results showed wide variations in testing rates, access to free testing and the types of tests recorded in national databases, which may substantially limit incidence comparability. By systematically including testing information when comparing incidence rates, these comparisons may be greatly improved. New indicators incorporating testing or existing indicators such as death or hospitalisation will be important to improving international comparisons.

Mpox outbreak in France: epidemiological characteristics and sexual behaviour of cases aged 15 years or older, 2022.

BackgroundLocally-acquired mpox cases were rarely reported outside Africa until May 2022, when locally-acquired-mpox cases occurred in various European countries.AimWe describe the mpox epidemic in France, including demographic and behavioural changes among a subset of cases, during its course.MethodsData were retrieved from the enhanced national surveillance system until 30 September 2022. Laboratory-confirmed cases tested positive for monkeypox virus or orthopoxviruses by PCR; non-laboratory-confirmed cases had clinical symptoms and an epidemiological link to a laboratory-confirmed case. A subset of ≥ 15-year-old male cases, notified until 1 August, was interviewed for epidemiological, clinical and sexual behaviour information. Association of symptom-onset month with quantitative outcomes was evaluated by t- or Wilcoxon tests, and with binary outcomes, by Pearson's chi-squared or Fisher exact tests.ResultsA total of 4,856 mpox cases were notified, mostly in Île-de-France region (62%; 3,025/4,855). Cases aged ≥ 15 years were predominantly male (97%; 4,668/4,812), with 37 years (range: 15-81) as mean age. Between May and July, among the subset interviewed, mpox cases increased in regions other than Île-de-France, and mean age rose from 35 (range: 21-64) to 38 years (range: 16-75; p = 0.007). Proportions of cases attending men-who-have-sex-with-men (MSM) meeting venues declined from 60% (55/91) to 46% (164/359; p = 0.012); median number of sexual partners decreased from four (interquartile range (IQR): 1-10) to two (IQR: 1-4; p < 0.001).ConclusionChanges in cases' characteristics during the epidemic, could reflect virus spread from people who were more to less behaviourally vulnerable to mpox between May and July, or MSM reducing numbers of sexual partners as recommended.

Early assessment of diffusion and possible expansion of SARS-CoV-2 Lineage 20I/501Y.V1 (B.1.1.7, variant of concern 202012/01) in France, January to March 2021.

The emergence of SARS-CoV-2 variant 20I/501Y.V1 (VOC-202012/1 or GR/501Y.V1) is concerning given its increased transmissibility. We reanalysed 11,916 PCR-positive tests (41% of all positive tests) performed on 7-8 January 2021 in France. The prevalence of 20I/501Y.V1 was 3.3% among positive tests nationwide and 6.9% in the Paris region. Analysing the recent rise in the prevalence of 20I/501Y.V1, we estimate that, in the French context, 20I/501Y.V1 is 52-69% more transmissible than the previously circulating lineages, depending on modelling assumptions.

Cluster of Coronavirus Disease 2019 (COVID-19) in the French Alps, February 2020.

BACKGROUND: On 7 February 2020, French Health authorities were informed of a confirmed case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an Englishman infected in Singapore who had recently stayed in a chalet in the French Alps. We conducted an investigation to identify secondary cases and interrupt transmission. METHODS: We defined as a confirmed case a person linked to the chalet with a positive reverse-transcription polymerase chain reaction sample for SARS-CoV-2. RESULTS: The index case stayed 4 days in the chalet with 10 English tourists and a family of 5 French residents; SARS-CoV-2 was detected in 5 individuals in France, 6 in England (including the index case), and 1 in Spain (overall attack rate in the chalet: 75%). One pediatric case, with picornavirus and influenza A coinfection, visited 3 different schools while symptomatic. One case was asymptomatic, with similar viral load as that of a symptomatic case. Seven days after the first cases were diagnosed, 1 tertiary case was detected in a symptomatic patient with from the chalet a positive endotracheal aspirate; all previous and concurrent nasopharyngeal specimens were negative. Additionally, 172 contacts were monitored; all contacts tested for SARS-CoV-2 (N = 73) were negative. CONCLUSIONS: The occurrence in this cluster of 1 asymptomatic case with similar viral load as a symptomatic patient suggests transmission potential of asymptomatic individuals. The fact that an infected child did not transmit the disease despite close interactions within schools suggests potential different transmission dynamics in children. Finally, the dissociation between upper and lower respiratory tract results underscores the need for close monitoring of the clinical evolution of suspected cases of coronavirus disease 2019.

The evolving blood donor deferral policy for men who have sex with men: impact on the risk of HIV transmission by transfusion in France.

BACKGROUND: Blood donation deferral for men who have sex with men (MSM) in France was reduced from permanent to 12 months in July 2016. To inform a further reduction of the deferral period, an HIV risk assessment was conducted with two scenarios: S1, 4-month deferral; S2, 4-month deferral only in the case of more than one sexual partner (i.e., similar to other blood donors). METHODS: Baseline HIV residual risk (RR) was calculated from July 2016 to December 2017, using the Incidence Rate-Window Period method. The impact of both scenarios on RR was assessed using data from surveys on MSM and blood donors, to estimate 1) the number of additional MSM expected to donate in each scenario and 2) HIV incidence among these donors. RESULTS: Baseline HIV RR was estimated at 1 in 6,380,000 donations. For S1, an additional 733 MSM donors, and an additional 0.09 HIV-positive donations were estimated, yielding an unchanged RR of 1 in 6,300,000. For S2, these numbers were estimated at 3102 and 3.92, respectively, yielding an RR of 1 in 4,300,000. Sensitivity analyses showed that, under worst-case assumptions, the RR would equal 1 in 6,225,000 donations for S1 and 1 in 3,000,000 for S2. CONCLUSION: For both scenarios, the HIV RR remains very low. For S1, the risk is identical to the baseline RR. For S2, it is 1.5 times higher, and sensitivity analysis shows that this estimate is less robust than for S1. The French Minister of Health announced that S1 will be implemented in April 2020.

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.

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.

Assessment of the impact of the extension of vaccination mandates on vaccine coverage after 1 year, France, 2019.

One year after the extension of the childhood vaccination mandates to the 11 routine vaccinations for children under 2 years old, we estimated vaccination coverage through vaccine reimbursement data. Coverage for children born in 2018 has notably increased. Moreover, vaccine coverage for children and for vaccines not concerned by the law have also shown an increasing trend, supporting a positive impact of the ongoing communication strategy on vaccination, beyond the extension of vaccination mandates.

Incidence of urinary tract infections and antibiotic resistance in the outpatient setting: a cross-sectional study.

PURPOSE: In 2012-2013, a cross-sectional survey was conducted in women visiting a general practitioner for urinary tract infection (UTI), to estimate the annual incidence of UTIs due to antibiotic-resistant Escherichia coli (E. coli). METHODS: A sampling design (stratification, stages and sampling weights) was taken into account in all analyses. Urine analyses were performed for each woman and centralised in one laboratory. RESULTS: Among 538 included women, urine culture confirmed UTI in 75.2 % of cases. E. coli represented 82.8 % of species. Among E. coli, resistance (I + R) was most common to amoxicillin [38 % (95 % confidence interval 31.1-44.5)] and to trimethoprim/sulfamethoxazole [18.1 % (12.0-24.1)]. Resistance to ciprofloxacin and cefotaxime was lower [1.9 % in both cases, (0.3-3.5)], as it was for nitrofurantoin [0.4 (0-1.0)] and fosfomycin (0). Extended-spectrum ß-lactamase (ESBL) represented 1.6 % of E. coli (0.2-2.9). Annual incidence rate of confirmed UTI was estimated at 2400 per 100,000 women (1800-3000). Incidence rates of UTI due to fluoroquinolone-resistant and ESBL-producing E. coli were estimated at 102 per 100,000 women (75-129) and at 32 (24-41), respectively. CONCLUSIONS: ESBL had been found in a community population, and even though the rate was low, it represents a warning and confirms that surveillance should continue.

Comparing antibiotic consumption between two European countries: are packages an adequate surrogate for prescriptions?

Defined daily doses (DDD) are the gold standard indicator for quantifying prescriptions. Since 2014, the European Centre for Disease Prevention and Control (ECDC) has also been using the number of packages per 1,000 inhabitants per day (ipd), as a surrogate for prescriptions, to report antibiotic consumption in the community and to perform comparisons between European Union (EU) countries participating in the European Surveillance of Antimicrobial Consumption Network (ESAC-Net). In 2015, consumption was reported to range across Europe from 1.0 to 4.7 packages per 1,000 ipd. Our analysis showed that consumption of antibiotics for systemic use per 1,000 ipd was on average 1.3 times greater in France than in Belgium when considering prescriptions in the numerator, 2.5 times greater when considering packages and 1.2 times greater when considering DDD. As long as the same metrics are used over time, antibiotic consumption data aggregated and disseminated by ECDC are useful for assessing temporal trends at the European level and within individual countries; these data may also be used for benchmarking across EU countries. While DDD - although imperfect - are the most widely accepted metric for this purpose, antibiotic packages do not appear suitable for comparisons between countries and may be misleading.

Survey of Clostridium difficile infection surveillance systems in Europe, 2011.

To develop a European surveillance protocol for Clostridium difficile infection (CDI), existing national CDI surveillance systems were assessed in 2011. A web-based electronic form was provided for all national coordinators of the European CDI Surveillance Network (ECDIS-Net). Of 35 national coordinators approached, 33 from 31 European countries replied. Surveillance of CDI was in place in 14 of the 31 countries, comprising 18 different nationwide systems. Three of 14 countries with CDI surveillance used public health notification of cases as the route of reporting, and in another three, reporting was limited to public health notification of cases of severe CDI. The CDI definitions published by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and the European Centre for Disease Prevention and Control (ECDC) were widely used, but there were differing definitions to distinguish between community- and healthcare-associated cases. All CDI surveillance systems except one reported annual national CDI rates (calculated as number of cases per patient-days). Only four surveillance systems regularly integrated microbiological data (typing and susceptibility testing results). Surveillance methods varied considerably between countries, which emphasises the need for a harmonised European protocol to allow consistent monitoring of the CDI epidemiology at European level. The results of this survey were used to develop a harmonised EU-wide hospital-based CDI surveillance protocol.

High Rate of Acquisition but Short Duration of Carriage of Multidrug-Resistant Enterobacteriaceae After Travel to the Tropics.

BACKGROUND: Multidrug-resistant Enterobacteriaceae (MRE) are widespread in the community, especially in tropical regions. Travelers are at risk of acquiring MRE in these regions, but the precise extent of the problem is not known. METHODS: From February 2012 to April 2013, travelers attending 6 international vaccination centers in the Paris area prior to traveling to tropical regions were asked to provide a fecal sample before and after their trip. Those found to have acquired MRE were asked to send fecal samples 1, 2, 3, 6, and 12 months after their return, or until MRE was no longer detected. The fecal relative abundance of MRE among all Enterobacteriaceae was determined in each carrier. RESULTS: Among 824 participating travelers, 574 provided fecal samples before and after travel and were not MRE carriers before departure. Of these, 292 (50.9%) acquired an average of 1.8 MRE. Three travelers (0.5%) acquired carbapenemase-producing Enterobacteriaceae. The acquisition rate was higher in Asia (142/196 [72.4%]) than in sub-Saharan Africa (93/195 [47.7%]) or Latin America (57/183 [31.1%]). MRE acquisition was associated with the type of travel, diarrhea, and exposure to ß-lactams during the travel. Three months after return, 4.7% of the travelers carried MRE. Carriage lasted longer in travelers returning from Asia and in travelers with a high relative abundance of MRE at return. CONCLUSIONS: MRE acquisition is very frequent among travelers to tropical regions. Travel to these regions should be considered a risk factor of MRE carriage during the first 3 months after return, but not beyond. CLINICAL TRIALS REGISTRATION: NCT01526187.

Population-based analysis of invasive fungal infections, France, 2001-2010.

To determine the epidemiology and trends of invasive fungal infections (IFIs) in France, we analyzed incidence, risk factors, and in-hospital death rates related to the most frequent IFIs registered in the national hospital discharge database during 2001-2010. The identified 35,876 IFI cases included candidemia (43.4%), Pneumocystis jirovecii pneumonia (26.1%), invasive aspergillosis (IA, 23.9%), cryptococcosis (5.2%), and mucormycosis (1.5%). The overall incidence was 5.9/100,000 cases/year and the mortality rate was 27.6%; both increased over the period (+1.5%, +2.9%/year, respectively). Incidences substantially increased for candidemia, IA, and mucormycosis. Pneumocystis jirovecii pneumonia incidence decreased among AIDS patients (-14.3%/year) but increased in non-HIV-infected patients (+13.3%/year). Candidemia and IA incidence was increased among patients with hematologic malignancies (>+4%/year) and those with chronic renal failure (>+10%/year). In-hospital deaths substantially increased in some groups, e.g., in those with hematologic malignancies. IFIs occur among a broad spectrum of non-HIV-infected patients and should be a major public health priority.

History of smallpox vaccination and marked clinical expression of mpox among cases notified in France from May to July 2022.

OBJECTIVES: The aim was to estimate the effect of reported history of smallpox vaccination prior to 1980 on clinical expression of mpox. METHODS: We included all confirmed mpox cases identified by the national mpox surveillance system in France between May and July 2022. Cases tested positive for monkeypox virus or orthopoxviruses by PCR. Cases were interviewed by phone using a questionnaire documenting demographics, symptoms and exposures. To estimate the effect of smallpox vaccination on the presence of marked mpox symptoms (association of fever, lymphadenopathy and extensive mucocutaneous lesions), we estimated prevalence ratios (PRs) and 95% CIs using Poisson regression models with robust standard errors. RESULTS: There were 1888 confirmed mpox cases with date of symptom onset between 7 May and 31 July 2022. Overall, 7% (93/1394) presented marked mpox symptoms. Among patients who provided information about their vaccination status, 14% (207/1469) reported smallpox vaccination prior to 1980. The proportion of cases with marked symptoms was 2% (3/170) among those reporting smallpox vaccination prior to 1980 and 8% (76/974) among those who reported no vaccination. The proportion of marked symptoms was four times lower among cases reporting previous smallpox vaccination than in cases reporting no vaccination (PR, 0.24; 95% CI: 0.08-0.76). There was no evidence of an effect of smallpox vaccination on development of complications (PR, 0.65; 95% CI: 0.35-1.22) or hospitalization due to mpox (PR, 0.64; 95% CI: 0.23-1.80). DISCUSSION: Our results suggest that smallpox vaccination during childhood attenuated the clinical expression of monkeypox virus infection, but there was no evidence of an effect on complications or hospitalization.

Nirsevimab Effectiveness Against Cases of Respiratory Syncytial Virus Bronchiolitis Hospitalised in Paediatric Intensive Care Units in France, September 2023-January 2024.

In September 2023, France was one of the first countries that started a national immunisation campaign with nirsevimab, a new monoclonal antibody against respiratory syncytial virus (RSV). Using data from a network of paediatric intensive care units (PICUs), we aimed to estimate nirsevimab effectiveness against severe cases of RSV bronchiolitis in France. We conducted a case-control study based on the test-negative design and included 288 infants reported by 20 PICUs. We estimated nirsevimab effectiveness at 75.9% (48.5-88.7) in the main analysis and 80.6% (61.6-90.3) and 80.4% (61.7-89.9) in two sensitivity analyses. These real-world estimates confirmed the efficacy observed in clinical studies.

National multidrug-resistant bacteria (MDRB) surveillance in France through the RAISIN network: a 9 year experience.

BACKGROUND: In the mid-1990s, the prevalence rate of multidrug-resistant bacteria (MDRB) in French hospitals was high and control of MDRB spread then became a major priority in the national infection control programme (ICP). METHODS: To evaluate the impact of the ICP, a national coordination of MDRB surveillance was set up in 2002. Data were collected 3 months a year in healthcare facilities (HCFs) on a voluntary basis. All clinical specimens of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBLE) were prospectively included. Incidences per 1000 patient days (PDs) were calculated and trends in incidence from 2003 to 2010 were assessed. RESULTS: Participation in the surveillance increased from 478 HCFs in 2002 to 933 in 2010. In 2010, MRSA incidence was 0.40/1000 PDs: 1.14 in intensive care units (ICUs), 0.48 in acute care facilities (ACFs) and 0.27 in rehabilitation and long-term care facilities (RLTCFs). ESBLE incidence was 0.39/1000 PDs: 1.63 in ICUs, 0.46 in ACFs and 0.23 in RLTCFs. MRSA incidence significantly decreased from 0.72/1000 PDs in 2003 to 0.41/1000 PDs in 2010 (P<10(-3)); in contrast, ESBLE incidence significantly increased from 0.17/1000 PDs to 0.48/1000 PDs (P<10(-3)). The most prevalent ESBLE were Enterobacter aerogenes (34%) and Escherichia coli (25%) in 2003 and E. coli (60%) and Klebsiella pneumoniae (18%) in 2010. CONCLUSION: These results demonstrate the positive impact of the national ICP on MRSA rates. In contrast, ESBLE incidence, especially ESBL-producing E. coli, is increasing dramatically and represents a serious threat for hospitals and for the community that deserves specific control actions.

Acquisition of Enterobacterales carrying the colistin resistance gene mcr following travel to the tropics.

BACKGROUND: Colistin is an antibiotic of last resort in the management of highly drug-resistant Enterobacterales infections. Travel to some destinations presents a high risk of acquiring multidrug-resistant Enterobacterales, but little data are available on the risk of acquiring colistin-resistant strains. Here, we use the VOYAG-R sample collection (2012-2013) in order to evaluate the rate of acquisition of colistin-resistant Enterobacterales, excluding species with intrinsic resistance (CRE), following travel to tropical regions. METHODS: A total of 574 frozen stool samples of travellers returning from tropical regions were screened for colistin-resistant strains using ChromID Colistin R agar (bioMerieux®) after pre-enrichment culture with 1 mg/L of colistin. Genomes were obtained by Illumina sequencing and genetic determinants of colistin resistance (mutational events and mcr genes) were searched. RESULTS: A total of 22 travellers (3.8%) acquired colistin-resistant Enterobacterales carrying an mcr gene. Acquisition rates varied between visited regions: 9.2% (18/195) for Asia (southeast Asia: 17/18), 2.2% (4/184) for Latin America (Peru: 4/4) and 0% from Africa (0/195). Acquired strains were predominantly Escherichia coli (92%) and carried mostly the mcr-1 variant (83%). Escherichia coli strains belonged mainly to commensal phylogroups A and B1, and were genetically highly diverse (5 non-clonal sequence type (ST)10 and 17 ST singletons). Only four non mcr colistin-resistant strains (two E. coli and two Enterobacter cloacae complex) were identified. Among all the strains, two also carried extended-spectrum beta-lactamase genes. CONCLUSIONS: Travel to tropical regions, and particularly to Southeast Asia, is a risk factor for the acquisition of mcr-carrying Enterobacterales. This study highlights the community dissemination of mcr in humans as early as 2012, 4 years prior to its first published description.

Outpatient Antibiotic Prescriptions in France: Patients and Providers Characteristics and Impact of the COVID-19 Pandemic.

In France, despite several successive plans to control antimicrobial resistance, antibiotic use remains high in the outpatient setting. This study aims to better understand outpatient antibiotic use and prescription in order to identify tailored targets for future public health actions. Using data from the French National Health Data System, we described and compared the individual characteristics of patients with and without an antibiotic prescription. The prescribed antibiotics (ATC-J01) were detailed and compared between 2019 and 2020. Antibiotic prescribing indicators that take prescriber activity into account were estimated and compared. Patients who were female, advanced age, and the presence of comorbidities were associated with antibiotic prescriptions. The overall prescription rate was estimated at 134 per 1000 consultations and 326 per 1000 patients seen in 2019. General practitioners (GPs), dentists and paediatricians were associated with 78.0%, 12.2% and 2.2% of antibiotic prescriptions, respectively, with high prescription rates (391, 447, and 313 p. 1000 patients seen, respectively). In comparison with 2019, this rate decreased in 2020 for paediatricians (-30.4%) and GPs (-17.9%) whereas it increased among dentists (+17.9%). The reduction was twice as high among the male prescribers than among their female counterparts (-26.6 and -12.0, respectively). The reduction in prescriptions observed in 2020 (-18.2%) was more marked in children (-35.8%) but less so among individuals ≥65 years (-13.1%) and those with comorbidities (-12.5%). The decrease in penicillin prescriptions represents 67.3% of the overall reduction observed in 2020. The heterogeneous decrease in prescriptions by age and antibiotic class could be explained by the impact of COVID-19 control measures on the spread of respiratory viruses; thus, a substantial proportion of the prescriptions avoided in 2020 is likely inappropriate, particularly among children. In order to keep the rate of prescriptions comparable to that observed in 2020, male prescribers, paediatricians and GPs should be encouraged to maintain that level, while a campaign to raise awareness of the appropriate use of antibiotics should be aimed at dentists in particular.

Severe hospital events following symptomatic infection with Sars-CoV-2 Omicron and Delta variants in France, December 2021-January 2022: A retrospective, population-based, matched cohort study.

Background: A rapid increase in incidence of the SARS-CoV-2 Omicron variant (sub-lineage BA.1) occurred in France in December 2021, while the Delta variant was prevailing since July 2021. We aimed to determine whether the risk of a severe hospital event following symptomatic SARS-CoV-2 infection differs for Omicron versus Delta. Methods: We conducted a retrospective cohort study to compare severe hospital events (admission to intensive care unit or death) between Omicron and Delta symptomatic cases matched according to week of virological diagnosis and age. The analysis was adjusted for age, sex, vaccination status, presence of comorbidities and region of residence, using Cox proportional hazards model. Findings: Between 06/12/2021-28/01/2022, 184 364 cases were included, of which 931 had a severe hospital event (822 Delta, 109 Omicron). The risk of severe event was lower among Omicron versus Delta cases; the difference in severity between the two variants decreased with age (adjusted Hazard Ratio (aHR)=0·13 95%CI: 0·08-0·20 among 40-64 years, aHR=0·50 95%CI: 0·26-0.98 among 80+ years). The risk of severe event increased with the presence of comorbidities (for very-high-risk comorbidity, aHR=4·15 95%CI: 2·86-6·01 among 40-64 years) and in males (aHR=2·28 95%CI: 1·82-2·85among 40-64 years) and was higher in unvaccinated compared to primo-vaccinated (aHR=7·29 95%CI: 5·58-9·54 among 40-64 years). A booster dose reduced the risk of severe hospital event in 80+ years infected with Omicron (aHR=0·29; 95%CI: 0·12-0·69). Interpretation: This study confirms the lower severity of Omicron compared to Delta. However, the difference in disease severity is less marked in the elderly. Further studies are needed to better understand the interactions between age and severity of variants. Funding: The study was performed as part of routine work at Public Health France.

Changing trends in vancomycin-resistant enterococci in French hospitals, 2001-08.

OBJECTIVES: Unprecedented outbreaks of vancomycin-resistant enterococci (VRE) have occurred in French hospitals since 2004. The aim of this study was to provide a picture of the spread and control of VRE in France and to characterize the isolates. METHODS: Notification of VRE cases to Institut de Veille Sanitaire has been mandatory since 2001. Isolates of VRE were sent to the National Reference Centre for species and vancomycin-resistance gene identification. Isolates were tested for antimicrobial susceptibility and typed by PFGE and multilocus sequence typing. RESULTS: Five hundred and four VRE notifications from 195 hospitals were recorded, corresponding to 2475 cases of infection (n=243) or colonization (n=2232) and 74 episodes of clustered cases. Outbreaks were controlled by implementation of infection control measures, although the number of new hospitals reporting isolation of VRE was increasing. The majority of 902 VRE isolated from 2006 to 2008 were Enterococcus faecium (94.8%) with the vanA or vanB gene. No isolate was resistant to linezolid, tigecycline or fusidic acid. PFGE analysis showed 161 different patterns. Generally a few predominant clones and several minor clones spread in a single hospital. In a subset of 46 representatives of PFGE clones, 13 different sequence types were characterized, all belonging to clonal complex CC17, while the esp and hyl genes were inconsistently detected. CONCLUSIONS: The national mandatory notification of unusual nosocomial events allowed rapid identification of VRE outbreaks and early implementation of control measures that have proved effective. However, VRE continue to emerge in a growing number of hospitals.