Bronchiolitis 2022-2023: One of the most unexpected outbreaks over this past decade, Nouvelle-Aquitaine, France.

BACKGROUND: Since the Covid-19 pandemic, bronchiolitis outbreaks have been subject to disrupted seasonality, and a major impact on the healthcare system was observed in 2022-23. OBJECTIVE: The aim of this article is to describe the characteristics of the 2022-23 bronchiolitis epidemic in the Nouvelle-Aquitaine region, and its impact on the healthcare system. METHOD: We described the indicators of dynamics, intensity, severity and impact provided by the bronchiolitis monitoring in place, and compared these with those from previous seasons. RESULTS: The intensity of the 2022-23 epidemic (emergency department visits: 23 %; SOS Médecins acts: 15 %), and its impact in terms of bronchiolitis-related hospitalizations (45 %) were higher than in previous seasons (p < 0.05). CONCLUSION: In addition to earliness, the 2022-23 bronchiolitis epidemic was significant as regards its exceptional scale and major impact on the hospital system, requiring adaptation of the preexisting healthcare offer in response to the anticipated demand.

Impact of the COVID-19 pandemic and lockdowns on emergency data related to mental health disorders in Nouvelle-Aquitaine, France.

This study estimates the association between emergency department (ED) visits for mental health disorders (MHDs) and the health context of the COVID-19 pandemic in the French region of Nouvelle-Aquitaine. This retrospective study took place between 2018 and 2021 using ED data. We defined the main exposure according to five periods: "Pre-pandemic (reference)", "First lockdown", "Second lockdown", "Third lockdown", and "Pandemic out-of-lockdown." We constructed the daily indicators for each MHD-related ED visit based on medical diagnoses. We described and then modeled the daily time series using generalized additive models with a quasi-Poisson regression. The analysis included 5,693,341 ED visits of which MHDs accounted for 4%. We observed a decline in ED use for most indicators, particularly during the first lockdown. Models revealed a statistically significant relative increase in ED visits for almost all MHDs during the first lockdown; for anxiety and child psychiatric disorders during the second lockdown; and only for child psychiatric disorders during the pandemic out-of-lockdown period. The public health crisis and lockdowns associated with the COVID-19 pandemic have been important sources of stress that could partially explain the deterioration of MHD indicators, thus leading to new public health concerns (notably among the youngest age group). Mental health is a major determinant of overall health and should therefore be considered in the management of crises that may require similar responses in the future.

Foodborne botulism outbreak involving different nationalities during the Rugby World Cup: critical role of credit card data and rapid international cooperation, France, September 2023.

In September 2023, a severe outbreak of type B botulism with fifteen cases was linked to consumption of canned sardines at a restaurant in Bordeaux, France, during the Rugby World Cup. The cases were from seven countries. One death was recorded. Outbreak investigation using credit card data, rapid communication between health authorities of the affected countries and broad media communication allowed identification of cases and exposed persons and prevented further severe outcomes.

One year of SARS-CoV-2 circulation in the Nouvelle-Aquitaine region, February 2021-2022, France.

Background: Since 2021, 3 variants of concern (VOC) have spread to France, causing successive epidemic waves. Objectives: To describe the features of Alpha, Delta and Omicron VOC circulation in the Nouvelle-Aquitaine region, France, between February 2021 and February 2022. Study design: Data from the three university hospitals (UH) of Nouvelle-Aquitaine were used to describe regional SARS-CoV-2 circulation (RT-PCR positive rates and identified VOC) as well as its consequences (total number of hospitalizations and admissions in intensive care unit). They were analyzed according to the predominant variant and compared with national data. Results: A total of 611,106 SARS-CoV-2 RT-PCR tests were performed in the 3 Nouvelle-Aquitaine UH during the study period. The 37,750 positive samples were analyzed by variant-specific RT-PCR or whole-genome sequencing. In 2021, Alpha VOC was detected from week 5 until week 35. Delta became the most prevalent variant (77.3%) in week 26, reaching 100% in week 35. It was replaced by Omicron, which was initially detected week 48, represented 77% of positive samples in week 52 and was still predominant in February 2022. The RT-PCR positive rates were 4.3, 4.2, and 21.9% during the Alpha, Delta and Omicron waves, respectively. The ratio between intensive care unit admissions and total hospitalizations was lower during the Omicron wave than during the two previous waves due to the Alpha and Delta variants. Conclusion: This study highlighted the need for strong regional cooperation to achieve effective SARS-CoV-2 epidemiological surveillance, in close association with the public health authorities.

Prevalence of SARS-CoV-2 antibodies in France: results from nationwide serological surveillance.

Assessment of the cumulative incidence of SARS-CoV-2 infections is critical for monitoring the course and extent of the COVID-19 epidemic. Here, we report estimated seroprevalence in the French population and the proportion of infected individuals who developed neutralising antibodies at three points throughout the first epidemic wave. Testing 11,000 residual specimens for anti-SARS-CoV-2 IgG and neutralising antibodies, we find nationwide seroprevalence of 0.41% (95% CI: 0.05-0.88) mid-March, 4.14% (95% CI: 3.31-4.99) mid-April and 4.93% (95% CI: 4.02-5.89) mid-May 2020. Approximately 70% of seropositive individuals have detectable neutralising antibodies. Infection fatality rate is 0.84% (95% CI: 0.70-1.03) and increases exponentially with age. These results confirm that the nationwide lockdown substantially curbed transmission and that the vast majority of the French population remained susceptible to SARS-CoV-2 in May 2020. Our study shows the progression of the first epidemic wave and provides a framework to inform the ongoing public health response as viral transmission continues globally.

Screening around a COVID-19 cluster: Exploring its impact on a local virus outbreak.

OBJECTIVE: In March 2020, we implemented screening of the contacts of a COVID-19 cluster having occurred in the Lot-et-Garonne department, the first department of the Nouvelle-Aquitaine region to be affected by the active circulation of SARS-CoV-2. We aimed to describe the impact of this screening on the local SARS-CoV-2 outbreak. METHODS: All high-risk contacts, as well as the individuals living in their households, were screened. We detailed the evolution of the number of confirmed COVID-19 cases in the Lot-et-Garonne department and the rest of the Nouvelle-Aquitaine region. RESULTS: Among the 89 screened individuals, 10 new cases were confirmed, including 4 asymptomatic persons. In Lot-et-Garonne, the number of confirmed COVID-19 cases immediately decreased after this screening and no epidemic peak occurred, contrary to what was observed in the rest of the region. CONCLUSION: The early screening of high-risk contacts of COVID-19 cases and members of their household implemented a few days before the first lockdown probably helped to prevent the spread of the virus in the department.

The role of livestock movements in the spread of Rift Valley fever virus in animals and humans in Mayotte, 2018-19.

Rift Valley fever (RVF) is a vector-borne viral disease of major animal and public health importance. In 2018-19, it caused an epidemic in both livestock and human populations of the island of Mayotte. Using Bayesian modelling approaches, we assessed the spatio-temporal pattern of RVF virus (RVFV) infection in livestock and human populations across the island, and factors shaping it. First, we assessed if (i) livestock movements, (ii) spatial proximity from communes with infected animals, and (iii) livestock density were associated with the temporal sequence of RVFV introduction into Mayotte communes' livestock populations. Second, we assessed whether the rate of human infection was associated with (a) spatial proximity from and (b) livestock density of communes with infected animals. Our analyses showed that the temporal sequence of RVFV introduction into communes' livestock populations was associated with livestock movements and spatial proximity from communes with infected animals, with livestock movements being associated with the best model fit. Moreover, the pattern of human cases was associated with their spatial proximity from communes with infected animals, with the risk of human infection sharply increasing if livestock in the same or close communes were infected. This study highlights the importance of understanding livestock movement networks in informing the design of risk-based RVF surveillance programs.

Impact des deux confinements sur le recours aux soins d'urgence lors de l'épidémie de COVID-19 en Nouvelle-Aquitaine.

INTRODUCTION: Following the emergence of the COVID-19 epidemic in France, several preventive measures have been put in place, including a mandatory lockdown of the entire population. This measure was intended to slow down the viral circulation and protect the healthcare system, especially hospital departments. The aim of this study was to describe the activity of emergency department (ED) during the two lockdowns related to the COVID-19 epidemic in the Nouvelle-Aquitaine region. METHOD: A retrospective descriptive analysis of ED visits was performed for the period December 09, 2019 to December 20, 2020. The distribution of the number of ED visits was studied. RESULTS: ED visits decreased by 50% during the first lockdown in line with the COVID-19 epidemic and by 30% during the second. Hospitalization rate increased during the two lockdowns (+ 48% and + 20%, respectively). A differentiated use was observed during both lockdowns, with the emergence of the use of care for "coronavirus", "stroke" or "dyspnea / respiratory failure" while the typical pathologies "ENT infections" or "skin infections" were no more or less observed. CONCLUSION: Data from Oscour® allowed a real-time monitoring of the COVID-19 epidemic in France, and to assess the impact of lockdown on ED activity in the region. A decline in the use of healthcare services, the increase in hospitalization rate and the pathologies observed during the two lockdowns are in favour of a refocusing of the recourse for most serious pathologies.

Early assessment of the impact of mitigation measures to control COVID-19 in 22 French metropolitan areas, October to November 2020.

In France, measures including curfew and lockdown were implemented to control the COVID-19 pandemic second wave in 2020. This study descriptively assesses their possible effects, also relative to their timing. A considerable decrease in incidence of COVID-19 cases and hospital admissions was observed 7 to 10 days after mitigation measures were put in place, occurring earlier in metropolitan areas which had implemented these first. This temporal coincidence suggests the measures' positive impact, consistent with international experiences.

Estimation of Rift Valley fever virus spillover to humans during the Mayotte 2018-2019 epidemic.

Rift Valley fever (RVF) is an emerging, zoonotic, arboviral hemorrhagic fever threatening livestock and humans mainly in Africa. RVF is of global concern, having expanded its geographical range over the last decades. The impact of control measures on epidemic dynamics using empirical data has not been assessed. Here, we fitted a mathematical model to seroprevalence livestock and human RVF case data from the 2018-2019 epidemic in Mayotte to estimate viral transmission among livestock, and spillover from livestock to humans through both direct contact and vector-mediated routes. Model simulations were used to assess the impact of vaccination on reducing the epidemic size. The rate of spillover by direct contact was about twice as high as vector transmission. Assuming 30% of the population were farmers, each transmission route contributed to 45% and 55% of the number of human infections, respectively. Reactive vaccination immunizing 20% of the livestock population reduced the number of human cases by 30%. Vaccinating 1 mo later required using 50% more vaccine doses for a similar reduction. Vaccinating only farmers required 10 times as more vaccine doses for a similar reduction in human cases. Finally, with 52.0% (95% credible interval [CrI] [42.9-59.4]) of livestock immune at the end of the epidemic wave, viral reemergence in the next rainy season (2019-2020) is unlikely. Coordinated human and animal health surveillance, and timely livestock vaccination appear to be key to controlling RVF in this setting. We furthermore demonstrate the value of a One Health quantitative approach to surveillance and control of zoonotic infectious diseases.

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.

Rift Valley Fever Outbreak, Mayotte, France, 2018-2019.

From November 2018 through July 2019, an outbreak of Rift Valley fever in humans occurred in Mayotte, France; 142 cases were confirmed. Exposure to animals or their biological fluid was reported by 73% of patients. Health authorities have been implementing control measures, including veterinary surveys, vector control interventions, and prevention measures.

Low seroprevalence of hepatitis E on Reunion island.

OBJECTIVE: Hepatitis E virus (HEV) has been scarcely investigated in the Indian Ocean. Following a nationwide serosurvey among blood donors, we conducted a population-based serosurvey to assess the magnitude of HEV exposure on Reunion Island. METHODS: Four hundred and sixty-six archived frozen human sera from the 2009 CoPanFlu-RUN cohort were analysed using the Wantai HEV IgG enzyme immunoassay. HEV seropositivity was defined as an IgG titre ≥5 UI/ml. Raw and weighted seroprevalences were assessed to account for the discrepancy between the CoPanFlu-RUN subset and the general community. Prevalence proportion ratios (PPR) were measured using log-binomial models. RESULTS: The raw and the weighted seroprevalences of HEV were 9.01% (95% CI 6.41-11.61) and 6.73% (95% CI 4.47-8.98), respectively. The presence of HEV IgG antibodies was associated with increasing age (P < 0.001). In a survey-adjusted model minimizing the sampling bias and adjusting for age, males were more likely to be seropositive than females (adjusted PPR 2.59, 95% CI 1.07-6.25). Seropositivity was spatially heterogeneous across the island (P < 0.01). Living in the neighbourhood of a pig farm within a low to intermediate slope area was associated with seropositivity in several models adjusting for age, gender, altitude of residency and interaction between slope and pig farms. CONCLUSION: Reunion Island is a low endemic area for HEV exposure. Despite limitations related to the retrospective study design, our findings confirm the roles of cumulative lifetime exposure and male gender in HEV exposure. The risk associated with neighbouring pig farms might also suggest environmental contamination in this setting.

From the threat to the large outbreak: dengue on Reunion Island, 2015 to 2018.

BackgroundWith more than 300 million infections estimated annually worldwide, dengue is the most prevalent arboviral infection. On Reunion Island, after a large outbreak in 1977-78, only limited episodes of viral circulation or sporadic cases were reported till 2015.AimOur objective was to document and report on the circulation of dengue virus after the occurrence of a small outbreak during austral summer 2015/16 and until the large outbreak of 2018.MethodsBeside the mandatory notification of biologically confirmed dengue cases, additional systems of surveillance were set up: estimation of dengue-like syndrome in people seeking care by their family doctor, surveillance of emergency department visits related to dengue, surveillance of hospitalised dengue patients and deaths classifications.ResultsAfter a moderate outbreak during summer 2015/16 with 231 cases, 2017 was characterised by limited viral circulation (97 cases) which, however, persisted during the austral winter. By February 2018, the number of cases had increased and led to a peak at the beginning of May 2018. More than 6,000 cases were reported this year (dengue virus type 2 only). In addition, six deaths of dengue patients were notified.ConclusionIn 2017, the persistence of transmission during winter created favourable conditions for the emergence of an epidemic during summer 2018. After this moderate epidemic wave, the viral circulation persisted during winter 2018 for the second year, opening the door for the second wave in 2019 and for potential endemisation of the disease on Reunion Island in the near future.

Vaccination coverage in the context of the emerging Yellow Fever threat in French Guiana.

BACKGROUND: French Guiana, a French overseas department located in South America between Brazil and Surinam, is the only European territory geographically located in the Amazonian forest complex and is considered endemic for yellow fever (YF). In the context of the emergent threat of YF in Latin America, we conducted a large household cross-sectional survey from June to October 2017 to estimate vaccination coverage in the population and to determine associations with sociodemographic and geographical characteristics. METHODOLOGY/PRINCIPAL FINDINGS: In total, 1,415 households and 2,697 individuals were included from the 22 municipalities of French Guiana. YF vaccination coverage was estimated at 95.0% (95% CI: 93.4-96.2) in the entire territory but was spatially heterogeneous, with the lowest levels estimated in the western part of the territory along the Surinamese cross-border region, particularly in children under 16 years who were not enrolled in school, immigrant adults and disadvantaged populations with low socioeconomic indexes. CONCLUSIONS/SIGNIFICANCE: Despite the good vaccination coverage against YF in the general population of French Guiana resulting from the compulsory nature of YF vaccination for residents and travelers, there is an urgent need to improve vaccination coverage in vulnerable populations living in the northwestern part of the territory to limit the risk of transmission in the context of the emerging YF threat in South America. Despite the relative rarity of YF and the significant number of infectious and tropical diseases in French Guiana, clinicians should adopt a high index of suspicion for YF, particularly in vulnerable and at-risk populations.

Seroprevalence of Coxiella burnetii (Q fever) Exposure in Humans on Reunion Island.

After the documentation of sporadic cases of Q fever endocarditis, we conducted a serosurvey to assess Coxiella burnetii exposure on Reunion Island. Two hundred forty-one stored frozen human sera were analyzed using an immunofluorescence assay. The weighted seroprevalence of Q fever was of 6.81% (95% confidence interval, 4.02%-9.59%). Despite the absence of infection in youths <20 years of age, exposure was not driven by age or by gender. There was a spatial disparity in exposure across the island, with higher prevalence being reported in regions where ruminant farms are present. The seroprevalence pattern suggests that Q fever is endemic on Reunion Island.

Seroprevalence of typhus group and spotted fever group Rickettsia exposures on Reunion island.

OBJECTIVE: Murine typhus has been increasingly reported on Reunion island, Indian ocean, following documentation of eight autochthonous infections in 2012-2013. We conducted a serosurvey to assess the magnitude of the seroprevalence of rickettsioses in the population. Two hundred and forty-one stored frozen sera taken from the 2009 Copanflu-RUN cohort were analysed using an immunofluorescence assay allowing to distinguish typhus group (TGR) and spotted fever group Rickesttsiae (SFGR). Seropositivity was defined for a dilution titre of Rickettsia IgG antibodies ≥ 1:64. Seroprevalence was weighted to account for the discrepancy between the Copanflu-RUN subset and the general population, as to infer prevalence at community level. Prevalence proportion ratios (PPR) were measured using log-binomial models. RESULTS: The weighted seroprevalences of typhus group rickettsioses and spotted fever group rickettsioses were of 12.71% (95% CI 8.84-16.58%) and 17.68% (95% CI 13.25-22.11%), respectively. Pooled together, data suggested that a fifth of the population had been exposed at least to one Rickettsia group. Youths (< 20 years) were less likely seropositive than adults (adjusted PPR 0.13, 95% CI 0.01-0.91). People living in the western dryer part of the island were more exposed (adjusted PPR 2.53, 95% CI 1.07-5.97). Rickettsioses are endemic on Reunion island and circulated before their first identification as murine typhus in year 2011. Surprisingly, since isolation of Rickettsia africae from Amblyomma variegatum in year 2004 or isolation of Rickettsia felis from Amblyomma loculosum, no autochthonous cases of African tick-bite fever or flea-borne spotted fever has yet been diagnosed.

Health monitoring during water scarcity in Mayotte, France, 2017.

BACKGROUND: During the 2016-2017 austral summer, unprecedented water scarcity was observed in the south of Mayotte, French island in the Indian Ocean. Therefore, authorities introduced restrictive measures to save the water of this part of the island. The rationing system affected over 65,000 people, for four months. In order to detect a possible deterioration of the health situation, a strengthened epidemiological surveillance system was set up. METHODS: Surveillance focused on intestinal and skin diseases, which are often associated with a lack of hygiene or poor-quality drinking and bathing water. Three pathologies were monitored: acute diarrhoea, acute gastroenteritis and skin diseases and also, proportion of antidiarrhoeal and rehydration solutions sales in pharmacies. Cases of leptospirosis were also under surveillance. The analyses consisted of comparing the collected data according to the areas that were either affected or not affected by the water restrictions. Comparisons with historical data were also made. RESULTS: Although none of the surveillance systems were able to demonstrate any impact on skin diseases, they revealed a very sharp increase in the proportion of consultations for acute diarrhoea and gastro-enteritis in the southern area. This was corroborated by a high increase in the sales of antidiarrhoeals and oral rehydration solutions via the sentinel pharmacists in the south of the island compared with those of the north. Comparison with historical data highlighted the occurrence of an unusual situation. CONCLUSION: These water restrictions caused a real deterioration in the health status of the inhabitants who were deprived of water.

Outbreak of IMI-1 carbapenemase-producing colistin-resistant Enterobacter cloacae on the French island of Mayotte (Indian Ocean).

The spread of carbapenemase-producing Enterobacteriaceae in the Southwest Indian Ocean islands is poorly known. Here we describe an outbreak of colistin-resistant Enterobacter cloacae harbouring blaIMI-1 in the French overseas department of Mayotte. Between October 2015 and January 2017, all isolates of imipenem-non-susceptible E. cloacae at Mayotte Medical Center and University Hospital of Reunion Island were screened for carbapenemase production. Positive isolates were typed by pulsed-field gel electrophoresis and whole-genome sequencing (WGS)-based multilocus sequence typing (MLST), and all ß-lactamase genes were identified by PCR and sequencing. Resistance profiles were determined by agar diffusion and Etest. Genetic support of the blaIMI-1 gene was determined by WGS. A total of 18 E. cloacae isolates harbouring blaIMI-1 were detected in 17 patients from Mayotte. Pulsed-field gel electrophoresis (PFGE) analysis showed 16 of the 18 strains to be clonally related and belonging to ST820. Based on clinical data, this outbreak most likely had a community origin. The blaIMI-1 gene in the 18 isolates was carried by a new variant of an integrative mobile element involving the Xer recombinases, called EcloIMEX-8. The mcr-1-mcr-5 genes were absent from the collection. The isolates belonged to E. cloacae cluster XI, known to be colistin heteroresistant. Here we report the first outbreak of IMI-1-producing Enterobacteriaceae. IMI-1-producers may be underdetected in microbiology laboratories because of their unusual antimicrobial resistance profile (resistant to imipenem but with intermediate resistance to ertapenem and susceptible to extended-spectrum cephalosporins) and the absence of blaIMI-1 in the panel of genes targeted by molecular diagnostic kits.

Status of imported malaria on Réunion Island in 2016.

BACKGROUND: Autochthonous malaria has been eliminated from Réunion in 1979. To prevent secondary transmission and re-emergence of autochthonous malaria, permanent epidemiologic and entomological surveillance and vector control measures are conducted around imported malaria cases. Results of local malaria surveillance (clinical data and results of epidemiological and entomological investigations around cases) were collected for 2013-2016 and were analysed according to historical data and to the exchanges with malaria-affected areas (estimated by airport data). RESULTS: Form 2013 to 2016, 95 imported malaria cases have been detected in Reunion Island: 42% of cases occurred in the area of repartition of Anopheles arabiensis, but Anopheles mosquitoes were present only around seven cases including one gametocyte carrier. No autochthonous or introduced case has occurred during this period. The lack of chemoprophylaxis or poor adherence was found in the majority (96%) of malaria cases between 2013 and 2016, regardless of trip type. Affinity tourism in Madagascar and Comoros was the cause of 65% of imported malaria cases. DISCUSSION: The incidence of imported malaria and the incidence rate per 100,000 travellers has continuously decreased since 2001. Now with the drastic decrease of malaria transmission in the Comoros archipelago, most of imported malaria cases in Reunion Island have been contaminated in Madagascar. Immigrants regularly resident in Reunion Island, which travel to malaria endemic countries (mainly Madagascar) to visit their friends and relatives (VFRs) represent a high-risk group of contracting malaria. VFRs, low adherence to pre-travel recommendations, in particular, the compliance on the use of chemoprophylaxis are the main drivers of imported malaria in Reunion Island. Furthermore as previously described, some general practitioners in Reunion Island are always not sufficiently aware of the official recommendations for prescriptions of prophylactic treatments. CONCLUSION: Social mobilization targeted on the Malagasy community in Reunion Island could help to decrease the burden of imported malaria in Reunion Island. Because of the low number of gametocyte carriers and the absence of an Anopheles mosquito population when most malaria cases were imported those last 4 years, the risk of the appearance of introduced malaria cases and indigenous malaria cases appears low in Reunion Island.