Background Obtaining a comprehensive quantitative figure of the determinants of influenza infection will help identify priority targets for future influenza mitigation interventions. We developed an original causal model integrating highly diverse factors and their dependencies, to identify the most critical determinants of pandemic influenza infection (H1N1pdm09) during the 2010–2011 influenza season. Methods We used data from 601 households (1450 participants) included in a dedicated cohort. Structural equations were used to model direct and indirect relationships between infection and risk perception, compliance with preventive behaviours, social contacts, indoor and outdoor environment, sociodemographic factors and pre-epidemic host susceptibility. Standardised estimates (β std ) were used to assess the strength of associations (ranging from −1 for a completely negative association to 1 for a completely positive association). Results Host susceptibility to H1N1pdm09 and compliance with preventive behaviours were the only two factors directly associated with the infection risk (β std =0.31 and β std =−0.21). Compliance with preventive behaviours was influenced by risk perception and preventive measures perception (β std =0.14 and β std =0.27). The number and duration of social contacts were not associated with H1N1pdm09 infection. Conclusions Our findings suggest that influenza vaccination in addition to public health communication campaigns focusing on personal preventive measures should be prioritised as potentially efficient interventions to mitigate influenza epidemics.

Background: Controversies about the 2009 H1N1 pandemic influenza vaccination might have impacted the motivational processes that underlie individual immunization against seasonal influenza. The purpose of this article is to investigate correlates of vaccine uptake during and after the pandemic.Methods: Data from the 1174 subjects of the CoPanFlu France cohort aged 15 and over were used. We used logistic regression models to identify social and behavioral predictors of getting vaccinated against seasonal influenza in 2009-2010 and in 2010-2011 and against H1N1 influenza in 2009-2010.Results: This study points out that correlates of vaccination behaviors varied according to the vaccine. Respondents under 65 years who adopted the seasonal influenza vaccine were, as usual, more likely to belong to a target group and have a lower education, contrary to subjects who chose the pandemic vaccine. Exceptionally during the pandemic, a higher socioeconomic status also led to adoption of either vaccine. Motivational processes differed by vaccine. Uptaking the "new" pandemic vaccine was the result of a deliberative decision-making process, influenced by cognitive factors related to the pandemic context (such as perceived severity of the H1N1 flu strain and trust in public health authorities). In contrast, respondents got the seasonal flu vaccine without relying on explicit justifications, but instead through habit of performing this behavior in the past.Conclusions: Target groups for seasonal influenza but not those for pandemic influenza were more likely to adopt the pandemic vaccine, which is a cause for great concern. This may be due to large extent to the automatic and habitual nature of influenza vaccination decisions. Public health authorities should pay more attention to situational than informational cues to facilitate vaccine uptake among priority groups, especially in case of mild pandemic influenza. (c) 2014 Elsevier Ltd. All rights reserved.

The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm) in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households). The GMT for the general population was 47.1 (95% confidence interval (CI): 45.1, 49.2). According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.

Controversies over the effectiveness and safety of the pandemic influenza A(H1N1)pdm09 vaccine in 2009/10 may have altered the influenza vaccination coverage in France after the pandemic season. The purpose of this study was to determine whether the pandemic affected seasonal influenza vaccination behaviours in the general population by analysing vaccination behaviours from 2006/07 to 2011/12 among the 1,451 subjects of the Cohort for Pandemic Influenza (CoPanFlu) France.We found that vaccination behaviours in 2010/11 and 2011/12 significantly differed from behaviours before the pandemic, with the notable exception of the targeted risk groups for seasonal influenza-related complications. Among the population with no risk factors,the post-pandemic influenza vaccine coverage decreased, with people aged 15 to 24 years and 45to 64 years being most likely to abandon vaccination.Therefore, this study documents a moderate negative effect of the 2009/10 pandemic episode on vaccination behaviours in the French metropolitan population that was apparent also in the following two seasons.Moreover, it does not exclude that the general trend of reduced vaccination has also affected certain targeted groups at high risk for complications.

Healthcare workers (HCWs) can be an important source of transmission of influenza to patients and family members, and their well‐being is fundamental to the maintenance of healthcare services during influenza outbreaks and pandemics. Unfortunately, studies have shown consistently low levels of compliance with influenza vaccination among HCWs, a finding that became particularly pronounced during recent pandemic vaccination campaigns. Among the variables associated with vaccine acceptance in this group are demographic factors, fears and concerns over vaccine safety and efficacy, perceptions of risk and personal vulnerability, past vaccination behaviours and experience with influenza illness, as well as certain situational and organisational constructs. We report the findings of a review of the literature on these factors and highlight some important challenges in interpreting the data. In particular, we point out the need for longitudinal study designs, as well as focused research and interventions that are adapted to the most resistant HCW groups. Multi‐pronged strategies are an important step forward in ensuring that future influenza vaccination campaigns, whether directed at seasonal or pandemic strains, will be successful in ensuring broad coverage among HCWs.

BACKGROUND:The risk of influenza infection depends on biological characteristics, individual or collective behaviors and the environmental context. The Cohorts for Pandemic Influenza (CoPanFlu) France study was set up in 2009 after the identification of the novel swine-origin A/H1N1 pandemic influenza virus. This cohort of 601 households (1450 subjects) representative for the general population aims at using an integrative approach to study the risk and characteristics of influenza infection as a complex combination of data collected from questionnaires regarding sociodemographic, medical, behavioral characteristics of subjects and indoor environment, using biological samples or environmental databases.METHODS/DESIGN:Households were included between December 2009 and July 2010. The design of this study relies on systematic follow-up visits between influenza seasons and additional visits during influenza seasons, when an influenza-like illness is detected in a household via an active surveillance system. During systematic visits, a nurse collects individual and environmental data on questionnaires and obtains blood samples from all members of the household. When an influenza-like-illness is detected, a nurse visits the household three times during the 12 following days, and collects data on questionnaires regarding exposure and symptoms, and biological samples (including nasal swabs) from all subjects in the household. The end of the follow-up period is expected in fall 2012.DISCUSSION:The large amount of data collected throughout the follow-up will permit a multidisciplinary study of influenza infections. Additional data is being collected and analyzed in this ongoing cohort. The longitudinal analysis of these households will permit integrative analyses of complex phenomena such as individual, collective and environmental risk factors of infection, routes of transmission, or determinants of the immune response to infection or vaccination.

The outbreak of chikungunya that occurred on French Island territories in the southwest Indian Ocean in 2005 and 2006 caused severe morbidity and mortality. In the aftermath, French authorities set up a scientific task force including experts in epidemiology, public health, entomology, virology, immunology, sociology, animal health, community and hospital medicine. The mission of the task force was to conceive and propose research programs needed to increase understanding of the disease and epidemic and to help public health officials in improving epidemic response measures. The purpose of this article is to describe the findings of the task force at the end of its two-year existence and initial outcomes in the the areas studied. Discussion emphasizes topics requiring further study.

This study relies on the first available data from the Cohorts for Pandemic Influenza (CoPanFlu)-France project, which is part of the CoPanFlu international consortium, aimed at studying individual and collective determinants of pandemic A/H1N1v influenza across different countries by setting up prospective cohorts of households. This primary analysis studies the association between elevated haemagglutination inhibition (HAI) antibody titers against A/H1N1v and influenza vaccination (seasonal or pandemic) at entry in the cohort. Inclusions began on December 4, 2009 and ended on July 23, 2010. Households were sampled using a random telephonic design in French general population. All household members were eligible to the cohort; however the inclusion of a household required the participation of all members. During the inclusion visits, nurses collected detailed data on subjects as well as blood samples. A standard HAI technique was adapted to the detection and quantification of antibodies to the 2009 A/H1N1v virus. Geometric mean titers (GMTs) were calculated for HAI assays with the use of generalized estimating equations for interval-censored data, and a "GMT ratio'' (GMTR) was defined as the multiplicative factor applied to the GMT in presence of an explanatory variable.This preliminary analysis included 1304 subjects belonging to 544 households. The GMT in the population was 35 4 [95% CI: 30 1; 41 8]. This GMT varied among age classes with values of 52 6 [39 2; 70 6], 28 5 [21 2; 38 3], and 38 3 [33 1; 44 5] for subjects below 15, between 15 and 50, and over 50, respectively. The other factors associated to an elevated GMT were previous vaccination by either the pandemic or the seasonal strain and history of influenza-like illness (ILI) since the beginning of the epidemic. In pandemic vaccine recipients, the GMT decreased after vaccination (GMTR: 0 89 [0 81; 0 99]) per month since pandemic vaccination.This study confirms previous findings that age, pandemic influenza vaccination, and history of ILI are associated with elevated post-seasonal GMT. This study also shows that seasonal influenza vaccination may have contributed to an increase of the HAI titer, especially in the elderly. Further analyses in this cohort are needed to confirm and explain these first results. The follow-up of subjects involved in the CoPanFlu-France cohort will provide data to study the risk factors for infection by the influenza virus.

Objectives. Since the emergence of the pandemic influenza A/H1N1, people were encouraged to adopt a large range of pharmaceutical and non-pharmaceutical measures in order to counter the risk of infection. The aim of this article is to identify and to explain the different types of preventive strategies adopted by the French population.Methods. The data are based on a phone survey conducted with a representative sample of the French population (N = 1003) in December 2009 (cooperation rate = 45.9%). Logistic regressions were used in order to characterize the different preventive behavioral patterns towards the A/H1N1 influenza.Results. Four types of behavioral strategies have been identified: 31.5% of the respondents combined vaccination (intention or action, regardless of the nature of the vaccine) with non-pharmaceutical measures, 8.8% wanted to get exclusively vaccinated, 42.0% took non-pharmaceutical steps only and 17.7% didn't protect themselves at all. Significant social and cognitive variables were found to predict membership of each group.Conclusions. These results indicate that a large majority of that is mainly population adopted a selective strategy rather than a cumulative one as it was recommended, a choice mostly explained by the level of risk perception. (C) 2010 Elsevier Inc. All rights reserved.

BACKGROUND: The identification of patterns of behaviors that lay people would engage in to protect themselves from the risk of infection in the case of avian influenza outbreak, as well as the lay perceptions of the threat that underlie these risk reduction strategies. METHODOLOGY/PRINCIPAL FINDINGS: A population-based survey (N = 1003) was conducted in 2008 to understand and describe how the French public might respond to a possible outbreak. Factor analyses highlighted three main categories of risk reduction strategies consisting of food quality assurance, food avoidance, and animal avoidance. In combination with the fear of contracting avian influenza, mental representations associated with the manifestation and/or transmission of the disease were found to significantly and systematically shape the behavioral responses to the perceived threat. CONCLUSIONS/SIGNIFICANCE: This survey provides insight into the nature and predictors of the protective patterns that might be expected from the general public during a novel domestic outbreak of avian influenza.

INTRODUCTION:Previous studies investigating determinants of 2009 (H1N1) pandemic influenza vaccine acceptance have focused on target groups such as healthcare workers. Few studies in the European Union have examined the self-reported reasons as well as predictive socio-demographic and health factors for pandemic influenza vaccine acceptance in the general population, even though influenza vaccine was recommended for all people.METHODS:A nationwide telephone survey was conducted in France during the peak of the outbreak that occurred in December 2009 in adults (≥ 16 years), using a proportional random-digit dialing.RESULTS:Interviews were completed by 1003 individuals, of whom 275 (27.4%) either had received pandemic influenza vaccine during the last weeks or intended to get vaccinated in the next weeks. Acceptance rates of pandemic vaccine were significantly higher among men, more educated and wealthier people, as well as persons who had a prior experience of influenza vaccination. The patterns of self-reported reasons for vaccine acceptance could be broadly divided into 3 groups related to (1) the mental representation of the threat - in particular the beliefs associated with the severity and personal vulnerability to the illness, (2) the perception of efficacy and safety of the vaccine, and (3) trust/distrust toward those advocating the vaccine.CONCLUSIONS:This national study indicates that social and cognitive determinants of pandemic influenza vaccine acceptance among French adults were relatively similar to those identified by previous studies of acceptance of seasonal influenza vaccine.

BACKGROUND:Vaccination against pandemic influenza A/H1N1 is an effective strategy to mitigate the spread of the disease. While the vaccine is now available, social acceptance remains relatively uncertain in many societies. The purpose of this study was to examine the beliefs, attitudes and practices associated with the intention to get vaccinated against the A/H1N1 virus among the general population in France.METHODS:A representative sample of 1001 individuals (stratified random recruitment procedure, ages 16-90 years) was interviewed by telephone. The questionnaire included a variety of items associated with socio-demographic characteristics, risk perceptions, illness perceptions, political attitudes and worldviews as well as intention to get vaccinated.RESULTS:More than 6 out of 10 of the respondents indicated that they planned to get vaccinated when the vaccine becomes available. The same proportion of parents also reported the intention to vaccinate their children against the disease. In multiple regression analyses, socio-cognitive factors consistently predicting influenza A/H1N1 vaccination were: level of worry, risk perception and previous experience of vaccine against seasonal flu.CONCLUSIONS:The factors found to predict vaccination intention and their distribution are assumed to be a consequence of the fact that people perceive the risk of swine flu to be similar to that of seasonal flu. As a result, in the absence of an increase of the risk perception of pandemic influenza A/H1N1, a very low level of actual vaccination is forecasted. Behavioural change would require that the risks and consequences of pandemic influenza A/H1N1 be perceived as highly different from seasonal flu.

Résumé Entre mars 2005 et mai 2006, l’île de la Réunion a été frappée par une épidémie de chikungunya qui a touché 260 000 personnes, soit près de 38 % de la population de l’île. Le chikungunya est une maladie virale, transmise par un moustique, contre laquelle il n’existe aucun traitement efficace. Une enquête socio-épidémiologique a été réalisée en mai 2006 auprès d’un échantillon représentatif de la population (N = 1 035) qui visait à identifier les facteurs en relation avec une probabilité élevée de contamination : d’une part, des facteurs objectifs, socio-économiques, démographiques et environnementaux, et d’autre part des facteurs subjectifs, tels que la perception du risque, de la maladie et des modes de protection disponibles, les connaissances et croyances sur l’origine et les modalités de transmission de la maladie, les attitudes, et les modes de protection utilisés. L’analyse montre que la contamination est associée de façon significative : d’une part, avec un niveau socio-économique caractérisant les personnes défavorisées et vivant dans une maison individuelle avec jardin ; d’autre part, avec l’existence de croyances alternatives (non démontrées scientifiquement) qui, couplées à une attitude fataliste, fondent un sentiment de non-contrôlabilité de la contamination. En matière de comportements, seul l’usage fréquent de répulsifs corporels (sprays et crèmes) s’est avéré associé à une réduction de la probabilité de contamination. Ainsi, conditions socio-économiques, habitat, système de croyances et comportements présentent une forte interdépendance qui dessine des modèles socioculturels plus ou moins favorables à la contamination.

A national survey on the public perception of the pandemic threat was conducted in France during the summer of 2008. Although the majority of the respondents displayed beliefs and attitudes toward the pandemic threat that could be considered as adaptive in the face of an outbreak, our results suggest that there are identifiable needs for public information about the transmission and prevention of the disease.

Vector-borne infectious diseases, such as malaria, dengue, chikungunya, and West Nile fevers are increasingly identified as major global human health threats in developing and developed countries. The success or failure of vector control rests mainly on the nature and scale of the behavioural response of exposed populations. Large-scale adoption of recommended protective behaviour represents a critical challenge that cannot be addressed without a better understanding of how individuals perceive and react to the risk of infection. Recently, French overseas territories faced large-scale outbreaks: an epidemic of chikungunya fever in La Re' union and Mayotte (2005-2006) and four successive outbreaks of dengue fever in one Caribbean island, Martinique (1995-2007). To assess how these populations perceived and responded to the risk, and how the nature and scale of protection affected their clinical status, socio-epidemiological surveys were conducted on each island during the outbreaks. These surveys address three crucial and interconnected questions relevant to the period after persons infected by the virus were identified: which factors shape the risk of acquiring disease? Which socio- demographic characteristics and living conditions induce a higher likelihood of infection? What is the impact of risk perception on protective behaviours adopted against mosquito bites? Grounded on the results of these surveys, a general framework is proposed to help draw out the knowledge needed to reveal the factors associated with higher probability of infection as an outbreak emerges. The lessons learnt can inform health authorities' efforts to improve risk communication programmes, both in terms of the target and content of messages, so as to explore new strategies for ensuring sustainable protective behaviour. The authors compare three epidemics of vector-borne diseases to elucidate psychosocial factors that determine how populations perceive and respond to the risk of infectious disease.

Les vecteurs, comme les agents pathogènes, ne connaissent pas de frontières, la distribution d’une espèce vectrice concernant le plus souvent une zone biogéographique. Par ailleurs, l’introduction d’une espèce (ou de populations à phénotypes particuliers tels que la résistance à un insecticide) se fait le plus souvent à partir de territoires contigus ou proches. La surveillance des vecteurs (distribution, abondance, niveau de sensibilité aux insecticides, comportement) et si possible la lutte antivectorielle doivent donc être réalisées au niveau régional. Des efforts de contrôle des vecteurs sur un territoire, voire des tentatives d’éradication, peuvent être réduits à néant s’ils ne sont pas réalisés en concertation avec les pays ou territoires voisins, à partir desquels la recolonisation est possible. Par ailleurs, les systèmes d’alerte précoce sont d’autant plus efficaces qu’ils tiennent compte des informations au niveau régional. Enfin des coopérations régionales et internationales peuvent permettre de partager des expériences et de faire des économies de moyen en termes de logistique et de formation (malgré la barrière de la langue).