The shielding of older individuals has been proposed to limit COVID-19 hospitalizations while rel... more The shielding of older individuals has been proposed to limit COVID-19 hospitalizations while relaxing general social distancing in the absence of vaccines. Evaluating such approaches requires a deep understanding of transmission dynamics across ages. Here, we use detailed age-specific case and hospitalization data to model the rebound in the French epidemic in summer 2020, characterize age-specific transmission dynamics and critically evaluate different age-targeted intervention measures in the absence of vaccines. We find that while the rebound started in young adults, it reached individuals aged ≥80 y.o. after 4 weeks, despite substantial contact reductions, indicating substantial transmission flows across ages. We derive the contribution of each age group to transmission. While shielding older individuals reduces mortality, it is insufficient to allow major relaxations of social distancing. When the epidemic remains manageable (R close to 1), targeting those most contributing to...
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2021
BACKGROUND The prevalence of hepatitis B virus (HBV) infection varies geographically around the w... more BACKGROUND The prevalence of hepatitis B virus (HBV) infection varies geographically around the world. However, the underlying reasons for this variation are unknown. Using a nationally representative population-based sample from all 58 administrative divisions in Cameroon, we examined the association between median maternal age at first childbirth in a preceding generation, a proxy for the frequency of mother-to-child transmission (MTCT) of HBV in a region, and the risk of chronic HBV infection, defined as positive surface antigen (HBsAg), in the index generation. METHODS We estimated a division-specific median maternal age at first childbirth using historical data from Demographic Health Surveys (DHS) in 1991/1998/2004/2011. We tested HBsAg in 2011 DHS participants. We used maps to display spatial variation and spatial models for the analysis. RESULTS In 14,150 participants (median 27 years old, 51% females), the overall weighted prevalence of HBsAg was 11.9% (95%CI: 11.0-12.8), w...
Background After one year of stop-and-go COVID-19 mitigation, in the spring of 2021 European coun... more Background After one year of stop-and-go COVID-19 mitigation, in the spring of 2021 European countries still experienced sustained viral circulation due to the Alpha variant. As the prospect of entering a new pandemic phase through vaccination was drawing closer, a key challenge remained on how to balance the efficacy of long-lasting interventions and their impact on the quality of life. Methods Focusing on the third wave in France during spring 2021, we simulate intervention scenarios of varying intensity and duration, with potential waning of adherence over time, based on past mobility data and modeling estimates. We identify optimal strategies by balancing efficacy of interventions with a data-driven “distress” index, integrating intensity and duration of social distancing. Results We show that moderate interventions would require a much longer time to achieve the same result as high intensity lockdowns, with the additional risk of deteriorating control as adherence wanes. Shorte...
Background Given its high economic and societal cost, policymakers might be reluctant to implemen... more Background Given its high economic and societal cost, policymakers might be reluctant to implement a large-scale lockdown in case of coronavirus disease (COVID-19) epidemic rebound. They may consider it as a last resort option if alternative control measures fail to reduce transmission. Aim We developed a modelling framework to ascertain the use of lockdown to ensure intensive care unit (ICU) capacity does not exceed a peak target defined by policymakers. Methods We used a deterministic compartmental model describing transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the trajectories of COVID-19 patients in healthcare settings, accounting for age-specific mixing patterns and an increasing probability of severe outcomes with age. The framework is illustrated in the context of metropolitan France. Results The daily incidence of ICU admissions and the number of occupied ICU beds are the most robust indicators to decide when a lockdown should be triggered. ...
BackgroundAs evidence shows that vaccine immunity to COVID-19 wanes with time and decreases due t... more BackgroundAs evidence shows that vaccine immunity to COVID-19 wanes with time and decreases due to variants, several countries are implementing booster vaccination campaigns. The objective of this study was to analyze the morbidity and mortality burdens of different primary and booster vaccination strategies against COVID-19, using France as a case study.MethodsWe used a deterministic, age-structured, compartmental model fitted to hospital admission data and validated against sero-prevalence data in France to analyze the impact of primary and booster vaccination strategies on morbidity and mortality assuming waning of immunity and increased virus transmissibility during winter.FindingsStrategies prioritizing primary vaccinations were systematically more effective than strategies prioritizing boosters. Regarding booster strategies targeting different age groups, their effectiveness varied with the levels of virus transmissibility, and according to the assumed loss of immunity for eac...
Background This systematic literature review aimed to summarize evidence for the added value of d... more Background This systematic literature review aimed to summarize evidence for the added value of drug sales data analysis for the surveillance of infectious diseases. Methods A search for relevant publications was conducted in Pubmed, Embase, Scopus, Cochrane Library, African Index Medicus and Lilacs databases. Retrieved studies were evaluated in terms of objectives, diseases studied, data sources, methodologies and performance for real-time surveillance. Most studies compared drug sales data to reference surveillance data using correlation measurements or indicators of outbreak detection performance (sensitivity, specificity, timeliness of the detection). Results We screened 3266 articles and included 27 in the review. Most studies focused on acute respiratory and gastroenteritis infections. Nineteen studies retrospectively compared drug sales data to reference clinical data, and significant correlations were observed in 17 of them. Four studies found that over-the-counter drug sale...
Several countries have implemented lockdowns to control their COVID-19 epidemic. However, questio... more Several countries have implemented lockdowns to control their COVID-19 epidemic. However, questions like “where” and “when” still require answers. We assessed the impact of national and regional lockdowns considering the French first epidemic wave of COVID-19 as a case study. In a regional lockdown scenario aimed at preventing intensive care units (ICU) saturation, almost all French regions would have had to implement a lockdown within 10 days and 96% of ICU capacities would have been used. For slowly growing epidemics, with a lower reproduction number, the expected delays between regional lockdowns increases. However, the public health costs associated with these delays tend to grow exponentially with time. In a quickly growing pandemic wave, defining the timing of lockdowns at a regional rather than national level delays by a few days the implementation of a nationwide lockdown but leads to substantially higher morbidity, mortality and stress on the healthcare system.
ABSTRACTTo date, no specific estimate of R0 for SARS-CoV-2 is available for healthcare settings. ... more ABSTRACTTo date, no specific estimate of R0 for SARS-CoV-2 is available for healthcare settings. Using inter-individual contact data, we highlight that R0 estimates from the community cannot translate directly to healthcare settings, with pre-pandemic R0 values ranging 1.3-7.7 in three illustrative healthcare institutions. This has implications for nosocomial Covid-19 control.
1On March 16 2020, French authorities ordered a large scale lockdown to counter the COVID-19 epid... more 1On March 16 2020, French authorities ordered a large scale lockdown to counter the COVID-19 epidemic wave rising in the country, stopping non-essential economic, educational, and entertainment activities, maintaining mainly food retailers and healthcare institutions. One month later, the number of new hospitalizations and ICU admissions had reached a plateau and were beginning a slow descent.We developed a spatialized, deterministic, age-structured, and compartmental SARS-CoV-2 transmission model able to reproduce the pre-lockdown dynamic of the epidemic in each of the 13 French metropolitan regions. Thanks to this model, we estimate, at regional and national levels, the total number of hospitalizations, ICU admissions, hospital beds requirements (hospitalization and ICU), and hospital deaths which may have been prevented by this massive and unprecedented intervention in France.If no control measures had been set up, between March 19 and April 19 2020, our analysis shows that almos...
The spread of carbapenemase-producing Enterobacteriaceae (CPE) in healthcare settings is a major ... more The spread of carbapenemase-producing Enterobacteriaceae (CPE) in healthcare settings is a major public health threat that has been associated with cross-border and local patient transfers between healthcare facilities. Since the impact of transfers on spread may vary, our study aimed to assess the contribution of a patient transfer network on CPE incidence and spread at a countrywide level, with a case study of France from 2012 to 2015. Our results suggest a transition in 2013 from a CPE epidemic sustained by internationally imported episodes to an epidemic sustained by local transmission events through patient transfers. Incident episodes tend to occur within close spatial distance of their potential infector. We also observe an increasing frequency of multiple spreading events, originating from a limited number of regional hubs. Consequently, coordinated prevention and infection control strategies should focus on transfers of carriers of CPE to reduce regional and inter-regional ...
Purpose Quadrivalent influenza vaccine (QIV) includes the same strains as trivalent influenza vac... more Purpose Quadrivalent influenza vaccine (QIV) includes the same strains as trivalent influenza vaccine (TIV) plus an additional B strain of the other B lineage. The aim of the study was to analyse the public health and economic impact of replacing TIV with QIV in different scenarios in Spain. Methods A dynamic transmission model was developed to estimate the number of influenza B cases prevented under TIV and QIV strategies (<65 years (high risk) and ≥65 years). This model considers cross-protective immunity induced by different lineages of influenza B. The output of the transmission model was used as input for a decision tree model that estimated the economic impact of switching TIV to QIV. The models were populated with Spanish data whenever possible. Deterministic univariate and probabilistic multivariate sensitivity analyses were performed. Results Replacing TIV with QIV in all eligible patients with current vaccine coverage in Spain may have prevented 138,707 influenza B cases per season and, therefore avoided 10,748 outpatient visits, 3,179 hospitalizations and 192 deaths. The replacement could save €532,768 in outpatient visit costs, €13 million in hospitalization costs, and €3 million in costs of influenza-related deaths per year. An additional €5 million costs associated with productivity loss could be saved per year, from the societal perspective. The budget impact from societal perspective would be €6.5 million, and the incremental cost-effectiveness ratio (ICER) €1,527 per quality-adjusted life year (QALY). Sensitivity analyses showed robust results. In additional scenarios, QIV also showed an impact at public health level reducing influenza B related cases, outpatient visits, hospitalizations and deaths. Conclusions Our results show public health and economic benefits for influenza prevention with QIV. It would be an efficient intervention for the Spanish National Health Service with major health benefits especially in the population ≥65-year.
Background Influenza epidemics significantly weight on the Brazilian healthcare system and its so... more Background Influenza epidemics significantly weight on the Brazilian healthcare system and its society. Public health authorities have progressively expanded recommendations for vaccination against influenza, particularly to the pediatric population. However, the potential mismatch between the trivalent influenza vaccine (TIV) strains and those circulating during the season remains an issue. Quadrivalent vaccines improves vaccines effectiveness by preventing any potential mismatch on influenza B lineages. Methods We evaluate the public health and economic benefits of the switch from TIV to QIV for the pediatric influenza recommendation (6mo-5yo) by using a dynamic epidemiological model able to consider the indirect impact of vaccination. Results of the epidemiological model are then imputed in a health-economic model adapted to the Brazilian context. We perform deterministic and probabilistic sensitivity analysis to account for both epidemiological and economical sources of uncertai...
Europe is now considered as the epicenter of the SARS-CoV-2 pandemic, France being among the most... more Europe is now considered as the epicenter of the SARS-CoV-2 pandemic, France being among the most impacted country. In France, there is an increasing concern regarding the capacity of the healthcare system to sustain the outbreak, especially regarding intensive care units (ICU). The aim of this study was to estimate the dynamics of the epidemic in France, and to assess its impact on healthcare resources for each French metropolitan Region. We developed a deterministic, age-structured, Susceptible-Exposed-Infectious-Removed (SEIR) model based on catchment areas of each COVID-19 referral hospitals. We performed one month ahead predictions (up to April 14, 2020) for three different scenarios (R0=1.5, R0=2.25, R0=3), where we estimated the daily number of COVID-19 cases, hospitalizations and deaths, the needs in ICU beds per Region and the reaching date of ICU capacity limits. At the national level, the total number of infected cases is expected to range from 22,872 in the best case (R0...
Hospital-acquired infections (HAIs), including emerging multi-drug resistant organisms, threaten ... more Hospital-acquired infections (HAIs), including emerging multi-drug resistant organisms, threaten healthcare systems worldwide. Efficient containment measures of HAIs must mobilize the entire healthcare network. Thus, to best understand how to reduce the potential scale of HAI epidemic spread, we explore patient transfer patterns in the French healthcare system. Using an exhaustive database of all hospital discharge summaries in France in 2014, we construct and analyze three patient networks based on the following: transfers of patients with HAI (HAI-specific network); patients with suspected HAI (suspected-HAI network); and all patients (general network). All three networks have heterogeneous patient flow and demonstrate small-world and scale-free characteristics. Patient populations that comprise these networks are also heterogeneous in their movement patterns. Ranking of hospitals by centrality measures and comparing community clustering using community detection algorithms shows that despite the differences in patient population, the HAI-specific and suspected-HAI networks rely on the same underlying structure as that of the general network. As a result, the general network may be more reliable in studying potential spread of HAIs. Finally, we identify transfer patterns at both the French regional and departmental (county) levels that are important in the identification of key hospital centers, patient flow trajectories, and regional clusters that may serve as a basis for novel wide-scale infection control strategies.
Mathematical modeling approaches have brought important contributions to the study of pathogen sp... more Mathematical modeling approaches have brought important contributions to the study of pathogen spread in healthcare settings over the last 20 years. Here, we conduct a comprehensive systematic review of mathematical models of disease transmission in healthcare settings and assess the application of contact and patient transfer network data over time and their impact on our understanding of transmission dynamics of infections. Recently, with the increasing availability of data on the structure of interindividual and interinstitution networks, models incorporating this type of information have been proposed, with the aim of providing more realistic predictions of disease transmission in healthcare settings. Models incorporating realistic data on individual or facility networks often remain limited to a few settings and a few pathogens (mostly methicillin-resistant Staphylococcus aureus). To respond to the objectives of creating improved infection prevention and control measures and be...
Contexte L’augmentation continue de l’incidence de gale en France met en lumiere le besoin d’inve... more Contexte L’augmentation continue de l’incidence de gale en France met en lumiere le besoin d’investiguer les raisons expliquant la progression de cette epidemie. Objectif Le but de cette etude est d’etudier les pratiques de gestion des cas de gale par les medecins generalistes, les pediatres et les dermatologues en termes de diagnostic, de prescription de traitements preventifs et curatifs, et de suivi clinique. Methodes Une etude transversale chez les medecins liberaux de Bretagne a ete realisee en avril 2013. L’echantillon a ete stratifie par type de medecin (dermatologues, generalistes et pediatres), par zone urbaine ou rurale et par departement (les quatre de la region). Les facteurs explicatifs probables de l’observance des medecins aux recommandations nationales de traitement et de gestion des cas de gale ont ete analyses a l’aide d’une regression logistique multivariee. Resultats L’etude estime l’incidence de la gale en Bretagne a approximativement 12 200 cas sur les sept mois precedents l’etude (septembre 2012–mars 2013). Seulement 34 % (IC95 % [27,8 %, 40,4 %]) des medecins suivaient les recommandations de duree de traitement, et 53,2 % (IC95 % [46,7 %, 59,5 %]) traitaient les contacts proches d’un cas diagnostique. Les dermatologues etaient les seuls, independamment d’autres facteurs, a suivre majoritairement toutes les recommandations de traitement. Etre medecin generaliste (OR = 0,049, IC95 % [0,01, 0,22]) ou pediatre (OR = 0,056, IC95 % [0,01, 0,2]) etait significativement associe au fait d’etre non-observant par rapport aux dermatologues. Conclusion L’epidemie de gale est en passe de devenir un probleme de sante publique majeur en France. En majorite, les praticiens traitant des cas semblent ne pas respecter les recommandations nationales de bonnes pratiques, ce qui pourrait expliquer le maintien de la diffusion du parasite. Cependant, l’etude montre que la plupart des medecins sont en demande d’informations complementaires pour eux-memes et pour leurs patients.
Introduction-Apparues en 2004, les cigarettes électroniques sont utilisées par des millions de pe... more Introduction-Apparues en 2004, les cigarettes électroniques sont utilisées par des millions de personnes dans le monde, dont de nombreux fumeurs, comme aide au sevrage tabagique. Cependant, leur place dans la lutte anti-tabac est controversée en raison d'un manque d'études permettant d'éclairer le débat de santé publique qu'elles suscitent. Méthodes-Une enquête transversale sur la population étudiante du campus de Villejean à Rennes a été réalisée en avril 2014. Les objectifs principaux étaient d'estimer la proportion d'utilisateurs dans la population étudiante et d'évaluer l'impact du « vapotage » sur la consommation de tabac. Une analyse multivariée a permis de mettre en évidence les principaux facteurs associés au vapotage régulier. Résultats-Les enquêteurs ont interrogé 1 362 étudiants (6,9% du campus). La proportion d'étudiants ayant expérimenté la cigarette électronique est estimée à 35,3% [32,8% ; 37,9%] pour 5,7% [4,5% ; 7,0%] de vapoteurs réguliers. L'analyse multivariée montre qu'être « fumeur quotidien » (ratio de prévalence ajusté (RP) 11,8 [IC95%:5,3-26,5]), penser que la cigarette électronique est un bon moyen de sevrage tabagique (RP 4,29 [IC95%:1,69-10,91]), et qu'elle est plus économique (RP 2,44 [IC95%:1,01-5,91]) sont les principaux facteurs associés au vapotage régulier. Les vapoteurs réguliers déclarent à 68% avoir diminué leur consommation de tabac, et à 24% l'avoir arrêtée. Conclusion-Bien que déclarative, cette étude évalue l'usage et l'impact potentiel de la cigarette électronique sur la diminution et l'arrêt du tabac chez les étudiants. Ces résultats montrent l'urgence de la réalisation d'études cliniques d'envergure permettant de mesurer précisément l'impact sanitaire de ce phénomène.
The shielding of older individuals has been proposed to limit COVID-19 hospitalizations while rel... more The shielding of older individuals has been proposed to limit COVID-19 hospitalizations while relaxing general social distancing in the absence of vaccines. Evaluating such approaches requires a deep understanding of transmission dynamics across ages. Here, we use detailed age-specific case and hospitalization data to model the rebound in the French epidemic in summer 2020, characterize age-specific transmission dynamics and critically evaluate different age-targeted intervention measures in the absence of vaccines. We find that while the rebound started in young adults, it reached individuals aged ≥80 y.o. after 4 weeks, despite substantial contact reductions, indicating substantial transmission flows across ages. We derive the contribution of each age group to transmission. While shielding older individuals reduces mortality, it is insufficient to allow major relaxations of social distancing. When the epidemic remains manageable (R close to 1), targeting those most contributing to...
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2021
BACKGROUND The prevalence of hepatitis B virus (HBV) infection varies geographically around the w... more BACKGROUND The prevalence of hepatitis B virus (HBV) infection varies geographically around the world. However, the underlying reasons for this variation are unknown. Using a nationally representative population-based sample from all 58 administrative divisions in Cameroon, we examined the association between median maternal age at first childbirth in a preceding generation, a proxy for the frequency of mother-to-child transmission (MTCT) of HBV in a region, and the risk of chronic HBV infection, defined as positive surface antigen (HBsAg), in the index generation. METHODS We estimated a division-specific median maternal age at first childbirth using historical data from Demographic Health Surveys (DHS) in 1991/1998/2004/2011. We tested HBsAg in 2011 DHS participants. We used maps to display spatial variation and spatial models for the analysis. RESULTS In 14,150 participants (median 27 years old, 51% females), the overall weighted prevalence of HBsAg was 11.9% (95%CI: 11.0-12.8), w...
Background After one year of stop-and-go COVID-19 mitigation, in the spring of 2021 European coun... more Background After one year of stop-and-go COVID-19 mitigation, in the spring of 2021 European countries still experienced sustained viral circulation due to the Alpha variant. As the prospect of entering a new pandemic phase through vaccination was drawing closer, a key challenge remained on how to balance the efficacy of long-lasting interventions and their impact on the quality of life. Methods Focusing on the third wave in France during spring 2021, we simulate intervention scenarios of varying intensity and duration, with potential waning of adherence over time, based on past mobility data and modeling estimates. We identify optimal strategies by balancing efficacy of interventions with a data-driven “distress” index, integrating intensity and duration of social distancing. Results We show that moderate interventions would require a much longer time to achieve the same result as high intensity lockdowns, with the additional risk of deteriorating control as adherence wanes. Shorte...
Background Given its high economic and societal cost, policymakers might be reluctant to implemen... more Background Given its high economic and societal cost, policymakers might be reluctant to implement a large-scale lockdown in case of coronavirus disease (COVID-19) epidemic rebound. They may consider it as a last resort option if alternative control measures fail to reduce transmission. Aim We developed a modelling framework to ascertain the use of lockdown to ensure intensive care unit (ICU) capacity does not exceed a peak target defined by policymakers. Methods We used a deterministic compartmental model describing transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the trajectories of COVID-19 patients in healthcare settings, accounting for age-specific mixing patterns and an increasing probability of severe outcomes with age. The framework is illustrated in the context of metropolitan France. Results The daily incidence of ICU admissions and the number of occupied ICU beds are the most robust indicators to decide when a lockdown should be triggered. ...
BackgroundAs evidence shows that vaccine immunity to COVID-19 wanes with time and decreases due t... more BackgroundAs evidence shows that vaccine immunity to COVID-19 wanes with time and decreases due to variants, several countries are implementing booster vaccination campaigns. The objective of this study was to analyze the morbidity and mortality burdens of different primary and booster vaccination strategies against COVID-19, using France as a case study.MethodsWe used a deterministic, age-structured, compartmental model fitted to hospital admission data and validated against sero-prevalence data in France to analyze the impact of primary and booster vaccination strategies on morbidity and mortality assuming waning of immunity and increased virus transmissibility during winter.FindingsStrategies prioritizing primary vaccinations were systematically more effective than strategies prioritizing boosters. Regarding booster strategies targeting different age groups, their effectiveness varied with the levels of virus transmissibility, and according to the assumed loss of immunity for eac...
Background This systematic literature review aimed to summarize evidence for the added value of d... more Background This systematic literature review aimed to summarize evidence for the added value of drug sales data analysis for the surveillance of infectious diseases. Methods A search for relevant publications was conducted in Pubmed, Embase, Scopus, Cochrane Library, African Index Medicus and Lilacs databases. Retrieved studies were evaluated in terms of objectives, diseases studied, data sources, methodologies and performance for real-time surveillance. Most studies compared drug sales data to reference surveillance data using correlation measurements or indicators of outbreak detection performance (sensitivity, specificity, timeliness of the detection). Results We screened 3266 articles and included 27 in the review. Most studies focused on acute respiratory and gastroenteritis infections. Nineteen studies retrospectively compared drug sales data to reference clinical data, and significant correlations were observed in 17 of them. Four studies found that over-the-counter drug sale...
Several countries have implemented lockdowns to control their COVID-19 epidemic. However, questio... more Several countries have implemented lockdowns to control their COVID-19 epidemic. However, questions like “where” and “when” still require answers. We assessed the impact of national and regional lockdowns considering the French first epidemic wave of COVID-19 as a case study. In a regional lockdown scenario aimed at preventing intensive care units (ICU) saturation, almost all French regions would have had to implement a lockdown within 10 days and 96% of ICU capacities would have been used. For slowly growing epidemics, with a lower reproduction number, the expected delays between regional lockdowns increases. However, the public health costs associated with these delays tend to grow exponentially with time. In a quickly growing pandemic wave, defining the timing of lockdowns at a regional rather than national level delays by a few days the implementation of a nationwide lockdown but leads to substantially higher morbidity, mortality and stress on the healthcare system.
ABSTRACTTo date, no specific estimate of R0 for SARS-CoV-2 is available for healthcare settings. ... more ABSTRACTTo date, no specific estimate of R0 for SARS-CoV-2 is available for healthcare settings. Using inter-individual contact data, we highlight that R0 estimates from the community cannot translate directly to healthcare settings, with pre-pandemic R0 values ranging 1.3-7.7 in three illustrative healthcare institutions. This has implications for nosocomial Covid-19 control.
1On March 16 2020, French authorities ordered a large scale lockdown to counter the COVID-19 epid... more 1On March 16 2020, French authorities ordered a large scale lockdown to counter the COVID-19 epidemic wave rising in the country, stopping non-essential economic, educational, and entertainment activities, maintaining mainly food retailers and healthcare institutions. One month later, the number of new hospitalizations and ICU admissions had reached a plateau and were beginning a slow descent.We developed a spatialized, deterministic, age-structured, and compartmental SARS-CoV-2 transmission model able to reproduce the pre-lockdown dynamic of the epidemic in each of the 13 French metropolitan regions. Thanks to this model, we estimate, at regional and national levels, the total number of hospitalizations, ICU admissions, hospital beds requirements (hospitalization and ICU), and hospital deaths which may have been prevented by this massive and unprecedented intervention in France.If no control measures had been set up, between March 19 and April 19 2020, our analysis shows that almos...
The spread of carbapenemase-producing Enterobacteriaceae (CPE) in healthcare settings is a major ... more The spread of carbapenemase-producing Enterobacteriaceae (CPE) in healthcare settings is a major public health threat that has been associated with cross-border and local patient transfers between healthcare facilities. Since the impact of transfers on spread may vary, our study aimed to assess the contribution of a patient transfer network on CPE incidence and spread at a countrywide level, with a case study of France from 2012 to 2015. Our results suggest a transition in 2013 from a CPE epidemic sustained by internationally imported episodes to an epidemic sustained by local transmission events through patient transfers. Incident episodes tend to occur within close spatial distance of their potential infector. We also observe an increasing frequency of multiple spreading events, originating from a limited number of regional hubs. Consequently, coordinated prevention and infection control strategies should focus on transfers of carriers of CPE to reduce regional and inter-regional ...
Purpose Quadrivalent influenza vaccine (QIV) includes the same strains as trivalent influenza vac... more Purpose Quadrivalent influenza vaccine (QIV) includes the same strains as trivalent influenza vaccine (TIV) plus an additional B strain of the other B lineage. The aim of the study was to analyse the public health and economic impact of replacing TIV with QIV in different scenarios in Spain. Methods A dynamic transmission model was developed to estimate the number of influenza B cases prevented under TIV and QIV strategies (<65 years (high risk) and ≥65 years). This model considers cross-protective immunity induced by different lineages of influenza B. The output of the transmission model was used as input for a decision tree model that estimated the economic impact of switching TIV to QIV. The models were populated with Spanish data whenever possible. Deterministic univariate and probabilistic multivariate sensitivity analyses were performed. Results Replacing TIV with QIV in all eligible patients with current vaccine coverage in Spain may have prevented 138,707 influenza B cases per season and, therefore avoided 10,748 outpatient visits, 3,179 hospitalizations and 192 deaths. The replacement could save €532,768 in outpatient visit costs, €13 million in hospitalization costs, and €3 million in costs of influenza-related deaths per year. An additional €5 million costs associated with productivity loss could be saved per year, from the societal perspective. The budget impact from societal perspective would be €6.5 million, and the incremental cost-effectiveness ratio (ICER) €1,527 per quality-adjusted life year (QALY). Sensitivity analyses showed robust results. In additional scenarios, QIV also showed an impact at public health level reducing influenza B related cases, outpatient visits, hospitalizations and deaths. Conclusions Our results show public health and economic benefits for influenza prevention with QIV. It would be an efficient intervention for the Spanish National Health Service with major health benefits especially in the population ≥65-year.
Background Influenza epidemics significantly weight on the Brazilian healthcare system and its so... more Background Influenza epidemics significantly weight on the Brazilian healthcare system and its society. Public health authorities have progressively expanded recommendations for vaccination against influenza, particularly to the pediatric population. However, the potential mismatch between the trivalent influenza vaccine (TIV) strains and those circulating during the season remains an issue. Quadrivalent vaccines improves vaccines effectiveness by preventing any potential mismatch on influenza B lineages. Methods We evaluate the public health and economic benefits of the switch from TIV to QIV for the pediatric influenza recommendation (6mo-5yo) by using a dynamic epidemiological model able to consider the indirect impact of vaccination. Results of the epidemiological model are then imputed in a health-economic model adapted to the Brazilian context. We perform deterministic and probabilistic sensitivity analysis to account for both epidemiological and economical sources of uncertai...
Europe is now considered as the epicenter of the SARS-CoV-2 pandemic, France being among the most... more Europe is now considered as the epicenter of the SARS-CoV-2 pandemic, France being among the most impacted country. In France, there is an increasing concern regarding the capacity of the healthcare system to sustain the outbreak, especially regarding intensive care units (ICU). The aim of this study was to estimate the dynamics of the epidemic in France, and to assess its impact on healthcare resources for each French metropolitan Region. We developed a deterministic, age-structured, Susceptible-Exposed-Infectious-Removed (SEIR) model based on catchment areas of each COVID-19 referral hospitals. We performed one month ahead predictions (up to April 14, 2020) for three different scenarios (R0=1.5, R0=2.25, R0=3), where we estimated the daily number of COVID-19 cases, hospitalizations and deaths, the needs in ICU beds per Region and the reaching date of ICU capacity limits. At the national level, the total number of infected cases is expected to range from 22,872 in the best case (R0...
Hospital-acquired infections (HAIs), including emerging multi-drug resistant organisms, threaten ... more Hospital-acquired infections (HAIs), including emerging multi-drug resistant organisms, threaten healthcare systems worldwide. Efficient containment measures of HAIs must mobilize the entire healthcare network. Thus, to best understand how to reduce the potential scale of HAI epidemic spread, we explore patient transfer patterns in the French healthcare system. Using an exhaustive database of all hospital discharge summaries in France in 2014, we construct and analyze three patient networks based on the following: transfers of patients with HAI (HAI-specific network); patients with suspected HAI (suspected-HAI network); and all patients (general network). All three networks have heterogeneous patient flow and demonstrate small-world and scale-free characteristics. Patient populations that comprise these networks are also heterogeneous in their movement patterns. Ranking of hospitals by centrality measures and comparing community clustering using community detection algorithms shows that despite the differences in patient population, the HAI-specific and suspected-HAI networks rely on the same underlying structure as that of the general network. As a result, the general network may be more reliable in studying potential spread of HAIs. Finally, we identify transfer patterns at both the French regional and departmental (county) levels that are important in the identification of key hospital centers, patient flow trajectories, and regional clusters that may serve as a basis for novel wide-scale infection control strategies.
Mathematical modeling approaches have brought important contributions to the study of pathogen sp... more Mathematical modeling approaches have brought important contributions to the study of pathogen spread in healthcare settings over the last 20 years. Here, we conduct a comprehensive systematic review of mathematical models of disease transmission in healthcare settings and assess the application of contact and patient transfer network data over time and their impact on our understanding of transmission dynamics of infections. Recently, with the increasing availability of data on the structure of interindividual and interinstitution networks, models incorporating this type of information have been proposed, with the aim of providing more realistic predictions of disease transmission in healthcare settings. Models incorporating realistic data on individual or facility networks often remain limited to a few settings and a few pathogens (mostly methicillin-resistant Staphylococcus aureus). To respond to the objectives of creating improved infection prevention and control measures and be...
Contexte L’augmentation continue de l’incidence de gale en France met en lumiere le besoin d’inve... more Contexte L’augmentation continue de l’incidence de gale en France met en lumiere le besoin d’investiguer les raisons expliquant la progression de cette epidemie. Objectif Le but de cette etude est d’etudier les pratiques de gestion des cas de gale par les medecins generalistes, les pediatres et les dermatologues en termes de diagnostic, de prescription de traitements preventifs et curatifs, et de suivi clinique. Methodes Une etude transversale chez les medecins liberaux de Bretagne a ete realisee en avril 2013. L’echantillon a ete stratifie par type de medecin (dermatologues, generalistes et pediatres), par zone urbaine ou rurale et par departement (les quatre de la region). Les facteurs explicatifs probables de l’observance des medecins aux recommandations nationales de traitement et de gestion des cas de gale ont ete analyses a l’aide d’une regression logistique multivariee. Resultats L’etude estime l’incidence de la gale en Bretagne a approximativement 12 200 cas sur les sept mois precedents l’etude (septembre 2012–mars 2013). Seulement 34 % (IC95 % [27,8 %, 40,4 %]) des medecins suivaient les recommandations de duree de traitement, et 53,2 % (IC95 % [46,7 %, 59,5 %]) traitaient les contacts proches d’un cas diagnostique. Les dermatologues etaient les seuls, independamment d’autres facteurs, a suivre majoritairement toutes les recommandations de traitement. Etre medecin generaliste (OR = 0,049, IC95 % [0,01, 0,22]) ou pediatre (OR = 0,056, IC95 % [0,01, 0,2]) etait significativement associe au fait d’etre non-observant par rapport aux dermatologues. Conclusion L’epidemie de gale est en passe de devenir un probleme de sante publique majeur en France. En majorite, les praticiens traitant des cas semblent ne pas respecter les recommandations nationales de bonnes pratiques, ce qui pourrait expliquer le maintien de la diffusion du parasite. Cependant, l’etude montre que la plupart des medecins sont en demande d’informations complementaires pour eux-memes et pour leurs patients.
Introduction-Apparues en 2004, les cigarettes électroniques sont utilisées par des millions de pe... more Introduction-Apparues en 2004, les cigarettes électroniques sont utilisées par des millions de personnes dans le monde, dont de nombreux fumeurs, comme aide au sevrage tabagique. Cependant, leur place dans la lutte anti-tabac est controversée en raison d'un manque d'études permettant d'éclairer le débat de santé publique qu'elles suscitent. Méthodes-Une enquête transversale sur la population étudiante du campus de Villejean à Rennes a été réalisée en avril 2014. Les objectifs principaux étaient d'estimer la proportion d'utilisateurs dans la population étudiante et d'évaluer l'impact du « vapotage » sur la consommation de tabac. Une analyse multivariée a permis de mettre en évidence les principaux facteurs associés au vapotage régulier. Résultats-Les enquêteurs ont interrogé 1 362 étudiants (6,9% du campus). La proportion d'étudiants ayant expérimenté la cigarette électronique est estimée à 35,3% [32,8% ; 37,9%] pour 5,7% [4,5% ; 7,0%] de vapoteurs réguliers. L'analyse multivariée montre qu'être « fumeur quotidien » (ratio de prévalence ajusté (RP) 11,8 [IC95%:5,3-26,5]), penser que la cigarette électronique est un bon moyen de sevrage tabagique (RP 4,29 [IC95%:1,69-10,91]), et qu'elle est plus économique (RP 2,44 [IC95%:1,01-5,91]) sont les principaux facteurs associés au vapotage régulier. Les vapoteurs réguliers déclarent à 68% avoir diminué leur consommation de tabac, et à 24% l'avoir arrêtée. Conclusion-Bien que déclarative, cette étude évalue l'usage et l'impact potentiel de la cigarette électronique sur la diminution et l'arrêt du tabac chez les étudiants. Ces résultats montrent l'urgence de la réalisation d'études cliniques d'envergure permettant de mesurer précisément l'impact sanitaire de ce phénomène.
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