Abstract The purpose of the study was to weigh the community burden of chikungunya determinants on Reunion island. Risk factors were investigated within a subset of 2101 adult persons from a population-based cross-sectional serosurvey, using Poisson regression models for dichotomous outcomes. Design-based risk ratios and population attributable fractions (PAF) were generated distinguishing individual and contextual (i.e. that affect individuals collectively) determinants. The disease burden attributable to contextual determinants was twice that of individual determinants (overall PAF value 89.5% vs. 44.1%). In a model regrouping both categories of determinants, the independent risk factors were by decreasing PAF values: an interaction term between the reporting of a chikungunya history in the neighbourhood and individual house (PAF 45.9%), a maximal temperature of the month preceding the infection higher than 28.5 °C (PAF 25.7%), a socio-economically disadvantaged neighbourhood (PAF 19.0%), altitude of dwelling (PAF 13.1%), cumulated rainfalls of the month preceding the infection higher than 65 mm (PAF 12.6%), occupational inactivity (PAF 11.6%), poor knowledge on chikungunya transmission (PAF 7.3%) and obesity/overweight (PAF 5.2%). Taken together, these covariates and their underlying causative factors uncovered 80.8% of chikungunya at population level. Our findings lend support to a major role of contextual risk factors in chikungunya virus outbreaks.

Dans un but d'échanges d'expérience, les collègues antillais étant actuellement confrontés à la première émergence du chikungunya (CHIKV) dans les Caraïbes, nous vous rappelons les arguments épidémiologiques, cliniques et radiologiques pour ou contre la nature neutropique du CHIKV, celle-ci restant sujette à controverses. Synthèse des données acquises lors de l'épidémie 2005-2006 à l'île de La Réunion, à partir de différentes sources (cohortes hospitalières des services de réanimation, neurologie et maladies infectieuses, la cohorte CHIMERE (CHIkungunya MERe-Enfant). Classement des encéphalites de l'adulte et de l'enfant selon les critères SPILF 2007, du nouveau-né selon les critères modifiés de l'ABN/BPAII (G. B). En population, l'incidence néonatale de l'encéphalite était de 163/100 000, de 18/100 000 chez l'enfant et de 8/100 000 chez l'adulte (> deux tiers survenant après l'âge de 65 ans), soient des taux supérieurs à ceux enregistrés dans les enquêtes sur les encéphalites de toute cause. Chez le nouveau-né, la chimie et la cytologie du LCR étaient le plus souvent dans les limites de la normale, le diagnostic étant porté directement (fœtus), ou en présence d'images d'oedème parenchymateux à l'IRM (séquences pondérées en diffusion) chez le nouveau-né. Chez l'adulte, le LCR était perturbé dans 100 % des cas, l'imagerie restant en règle générale non spécifique. La létalité était nulle chez le nouveau-né, de l'ordre de 20 % chez l'enfant et de 28 % chez l'adulte. Aucune autopsie ne permettait de déceler le tropisme cellulaire du virus au niveau du parenchyme cérébral. En dépit d'arguments épidémio-cliniques en faveur de l'encéphalite, les éléments réunis dans ces différents travaux sont actuellement insuffisants pour plaider la nature primitivement neurotropique du CHIKV.

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.

The epidemic of chikungunya (CHIK) that swept through Reunion Island from late 2005 to mid 2006 affected 38.2% of the population, i.e., 300000 people. Although this outbreak took place in a French overseas department with high public health standards, failure to anticipate a large-scale epidemic associated with unprecedented severity and unexpectedly high mortality led to a major public health crisis. The purpose of this report is to provide a complete account of the experience of hospital intensive care physicians in addressing problems ranging from discovery of severe forms to management of a major health crisis. This report underlines the role of the head hospital physician and the necessity of mutual trust and collaboration with supervisory authorities.

Between August and September 2009, on Reunion Island, our Intensive Care Unit (ICU) treated several severe Influenza A (H1N1)S-OIV cases. We report the following case: a 23-year-old female patient with no prior medical history presented a severe respiratory distress that required high frequency oscillation ventilation and finally Extracorporeal Membrane Oxygenation (ECMO). She was hospitalized in the ICU for 41 days. Recovery was complete. It is important to note the stead of each technique in those types of respiratory distresses and describe the practical details of the ECMO's set up by a non-trained medical crew. We want to underline, within the current context of severe respiratory distresses due to Influenza A pandemic, the necessity to develop a multidisciplinary care network, or to reinforce the existing channels between well-trained medical crews familiar with ECMO's technics and the ICU that are not. (C) 2009 Elsevier Masson SAS. All rights reserved.

Objectives - To describe the characteristics treatment and outcome of critically ill patients with influenza A(H1N1) infection at St Pierre Hospital in Reunion Island during the 2009 outbreak as well as the measures of care reorganization implemented to face themPatients and methods - Prospective observational study of probable and confirmed cases of influenza A(H1N1)/2009 infection concerning hospitalized patients in a polyvalent intensive care unit (ICU)Results - Thirteen patients have been included between August and September 2009 Three (23 %) didn t have any medical history The median age was 42 [22-69] Eleven have required pulmonary ventilation for 10 3 days (+/- 8) Three (23%) have developed an ARDS Three patients (23%) died To cope with the influx of cases and considering our situation of geographic isolation it has been needed to totally rework the organization of care set-up of a specific welcoming channel division into sectors of the department opening of additional beds new on duty assignment inter and intra hospital cooperationConclusion - Reunion Island has been an experimental lab of crisis management during the H1N1/2009 epidemic several months ahead of the mother country To anticipate the reorganization of care in intensive care units during an outbreak period particularly in small units or units isolated like ours looks to us a must so to quietly face a sharp influx of patients (C) 2010 Elsevier Masson SAS All rights reserved