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International audience; To strengthen active dengue surveillance in Saint Martin and Saint Barthélemy, two French Caribbean islands, we evaluated the epidemiological usefulness of collecting blood samples from NS1-positive dengue patients on filter paper to identify the dengue serotypes circulating in these regions during a 27-month period. This approach allowed dengue serotypes to be identified by reverse transcriptase-polymerase chain reaction in 90.1% of the total set of 666 samples analyzed and, in 95.5% of the samples collected during the acute phase of the disease. This prospective virological surveillance using blood samples absorbed onto filter paper, which were stored at 4°C and shipped at ambient temperature to a specialized laboratory for analysis, allowed us to avoid the logistic and financial costs associated with shipping frozen venous blood samples. This surveillance system offers a low-cost alternative for reinforcing dengue prevention in areas where specialized laboratories do not exist, notably by facilitating the early detection of potentially new dengue serotypes.

Introduction Depuis 2009, sante publique France (ex-InVS) et ses cellules regionales (Cire) ont mis en place des surveillances des cas de grippe severe (SGS), basees sur la collaboration des services de reanimation hospitaliere avec les Cire. Apres plusieurs saisons de surveillance, une heterogeneite des taux de cas signales a ete observee selon le virus predominant et la region. Une etude a ete mise en place sur 21 regions pour les saisons 2009–10 a 2012–13 afin d’evaluer l’exhaustivite de la surveillance et d’etudier les facteurs expliquant les variations regionales. Materiels et methodes Le PMSI-Sniiram renseigne des informations sur chacun des sejours hospitaliers en France et permet de recenser les patients ayant un diagnostic code grippe. Un algorithme d’identification des cas communs entre les sources SGS et PMSI a ete construit a partir des informations communes : hopital, date d’admission, âge et sexe. Pour le calcul d’exhaustivite des sources, le nombre de cas total a ete estime par une methode de capture-recapture a deux sources, sous l’hypothese d’independance des sources. Une typologie des modalites de surveillance appliquees en region a ete etablie a partir d’une enquete exploratoire aupres des Cire. L’impact des modalites sur l’exhaustivite a ete analyse par une etude ecologique utilisant une regression de Poisson multiniveau. Resultats Pour les 17 regions metropolitaines participantes, le nombre total de cas de grippe severe etait estime a 4435 [4352–4519] sur les quatre saisons etudiees. La surveillance en identifie 2103, soit une exhaustivite globale de 47 %. Quatre regions ont des valeurs d’exhaustivite extremes allant de 28 a 74 % et les 13 autres regions entre 40 et 60 %. Seule la relance hebdomadaire des reanimateurs accompagnee d’un bilan etait significativement associee a une meilleure exhaustivite : 63 contre 46 % pour les regions qui n’en envoyaient pas (p = 0,02). Le PMSI identifie 3237 cas, soit une exhaustivite de 73 %. L’incidence nationale estimee au moyen des deux sources variait de 14 cas par million d’habitants (/M) en 2011–2012 a 30/M en 2009–10 et 2012–13. L’incidence regionale moyenne sur les 4 saisons variait de 9/M en Midi-Pyrenees a 31/M en Rhone-Alpes. Conclusion La surveillance n’avait permis d’identifier que la moitie de l’ensemble des cas hospitalises en reanimation sur les saisons etudiees. L’etude a permis de mesurer l’heterogeneite regionale de l’exhaustivite et de mettre en evidence un gradient geographique avec des taux d’incidence plus eleves dans l’Est de la France. La bonne exhaustivite du codage grippe dans le PMSI justifierait l’utilisation d’un tel croisement avec les donnees consolidees du PMSI en fin de saison, pour interpreter les variations d’incidence.

Background Sentinel general practitioner networks monitor influenza-like infections (ILI) in Martinique and in Guadeloupe (French West Indies). During the A(H1N1)2009 pandemic, they gave an ILI incidence estimation higher in Martinique than in Guadeloupe. In October 2009, a telephonic survey was launched in both islands to assess the number of ILI diagnoses performed by general practitioners since the beginning of the pandemic. This paper compares the results of sentinel surveillance, of telephonic survey and of hospital surveillance in Guadeloupe and in Martinique. Methods On each island, the sentinel network gathers a representative sample of voluntary general practitioners. Each week, they report the number of ILI they diagnosed the past week. Times series of these weekly numbers were modelized using the Serfling method with the upper limit of the confidence interval of the expected value representing the epidemic threshold. The telephone survey was conducted from October 2, 2009 to October 12, 2009 in Martinique and from October 13, 2009 to October 21, 2009 in Guadeloupe. The quota method was used for sampling individuals older than 14 years, leading to 507 interviews in Guadeloupe and 508 in Martinique. Results The epidemic lasted 12 weeks in both islands, from August 3 to October 25 in Martinique and from August 17 to November 8 in Guadeloupe. During August and September, estimated attack rate in Martinique was 5.52% (CI95: 5.23–5.83) from the sentinel network versus 8.3% (CI95: 6.0–11.0) from the telephone survey. In Guadeloupe, it was 2.13% (CI95: 1.97–2.24) from the sentinel network versus 6.9% (CI95: 4.8–9.5) from the telephone survey. An equivalent number of confirmed hospitalized cases was observed in the two islands. Conclusion These results suggest that the sentinel network underestimates ILI incidence in Guadeloupe. According to Emergency Room activity for ILI, it seems possible that ILI incidence was actually higher in Martinique. A lower proportion of swab sampling among ILI hospitalized people could partly explain the observed differences in hospitalization ratio, in severity and in lethality between the two islands.

Les regions de Guadeloupe, de Guyane et de la Martinique et les collectivites de Saint-Martin et Saint-Barthelemy ont deploye au niveau local un dispositif specifique pour surveiller l’emergence de la grippe A(H1N1) 2009. Apres une phase de confinement basee sur la detection et la gestion individuelle des cas, une surveillance a ete mise en place a l’echelle populationnelle, essentiellement basee sur les donnees des reseaux de medecins sentinelles et les confirmations virologiques. Tout comme l’ensemble des pays de la zone caraibe, les cinq territoires ont subi une epidemie liee au virus A(H1N1) 2009 ayant debute entre aout et septembre 2009. Malgre une dynamique similaire, ces vagues epidemiques ont presente des specificites en termes d’ampleur et de severite, avec un taux d’attaque variant de 28 a 70 pour 1 000 habitants et un taux d’hospitalisation de 4,3 a 10,3 pour 1 000 cas. Les outils de surveillance mis en place ont permis d’obtenir une vision globale et precise des caracteristiques de l’epidemie et semblent donc tout a fait adequats pour surveiller une eventuelle nouvelle vague epidemique. Certaines difficultes liees au contexte geographique ou sanitaire specifique des territoires concernes (complexite de l’acheminement des prelevements pour la surveillance virologique, survenue concomitante d’epidemies de dengue) sont apparues, et a l’inverse certaines specificites locales (presence de comites d’experts et de reseaux actifs de medecins sentinelles) ont facilite la surveillance et la gestion de l’episode.

Introduction Lors de la pandemie grippale A (H1N1) en 2009, l’Institut de veille sanitaire et ses cellules regionales (les Cire) ont mis en place des surveillances des cas severes de grippe, basees sur la collaboration des services de reanimation hospitaliere avec les Cire. La qualite de ces systemes n’a pas fait l’objet d’evaluation jusque la, en particulier en termes d’exhaustivite des cas signales. Une telle demarche permettrait d’evaluer le nombre de cas severes de grippe et les disparites regionales. Methode Une base de donnees hospitaliere, le Programme de medicalisation des systemes d’information (PMSI), contient des informations sur les patients ayant un diagnostic code « grippe ». Le croisement des cas de grippe severe identifies par les deux sources d’information sur les saisons grippales de 2009–2010 a 2012–2013 a ete initie dans 13 regions (representant 68 % de la population francaise) a partir d’une requete du PMSI/Sniiram. Le principe est d’identifier les cas communs et les cas non communs afin d’estimer les exhaustivites des deux sources d’information par une methode de capture–recapture, sous l’hypothese d’independance des sources. L’algorithme de croisement a ete construit a partir des informations communes : hopital, reanimation adulte ou pediatrique, date d’admission, âge et sexe du patient. Une etude descriptive des differents systemes de surveillance animes par les Cire a egalement ete realisee. L’objectif de ce travail est d’aboutir, pour les saisons grippales suivantes, a l’utilisation en routine d’un croisement automatise pour interpreter les variations d’incidences entre les regions. Resultats Pour les 12 regions metropolitaines, le PMSI/Sniiram recense 3276 sejours en service de reanimation pour grippe sur les quatre saisons grippales etudiees, avec des taux moyens par region, allant de 11,1 sejours par million d’habitants en Bretagne a 24,7 en Ile-de-France. Discussion Les premiers resultats suggerent des differences d’incidences regionales importantes.

During the summer of 2014, all the pre-requisites for autochthonous transmission of chikungunya virus are present in southern France: a competent vector, Aedes albopictus, and a large number of travellers returning from the French Caribbean islands where an outbreak is occurring. We describe the system implemented for the surveillance of chikungunya and dengue in mainland France. From 2 May to 4 July 2014, there were 126 laboratory-confirmed imported chikungunya cases in mainland France.

International audience; Dengue fever has been endemo-epidemic in the whole Region of America. In 2010, Guadeloupe and Martinique experienced historical epidemics, with an estimated attack rate of 10% in two islands. When considering the temporal evolution of epidemiological indicators, an unusual increase in the number of dengue cases could be detected very early. Two main factors might have facilitated the settlement of a viral transmission despite the dry season: a low immunity of the population against the circulating serotype and particular climatic conditions, notably very high temperatures which could have improved both virus and vector efficiency. This unusual situation was considered as a warning sign, and indeed led to major outbreaks in both islands a few weeks later. This event underlines that follow-up of epidemiological indicators is necessary to detect the unusual situations as soon as possible. Furthermore, development of biological and modelling tools should be promoted, as well as integrated management strategies for dengue prevention and control.

International audience; OBJECTIVE: To describe the methodology used for implementing a surveillance system specifically for influenza A(H1N1)pdm09 in the French West Indies and French Guiana during an outbreak of this new virus in 2009-2010, and to report its main results. METHODS: This was an observational descriptive study of confirmed and probable cases of influenza A(H1N1)pdm09 hospitalized for at least 24 hours in 23 July 2009-3 March 2010. Reverse transcription polymerase chain reaction was performed on nasopharyngeal swab samples according to the Centers for Disease Control and Prevention protocol. A probable case was defined as fever > 38ºC or aches or asthenia with respiratory symptoms (cough or dyspnea). All confirmed and probable hospitalized cases were reported, along with patient's age, sex, clinical condition at admission, place and length of hospitalization, antiviral treatment, underlying conditions, complications, and clinical evolution. A case was classified as severe if respiratory assistance or intensive care was required or if death resulted. RESULTS: A total of 331 confirmed and 16 probable cases were hospitalized, with a hospitalization rate ranging from 4.3 per 1 000 clinical cases in Saint Martin to 10.3 in French Guiana. Of these, 36 were severe, and subsequently, 10 were fatal. The median length of stay was 4 days for non-severe cases and 9 days for severe (P < 0.05). The mean patient age was 21 years, and severe cases were significantly older than non-severe (mean: 38 years versus 19 years, P < 0.05). Underlying conditions associated with a higher risk of severity were 65 years of age or more (RR = 7.5, 95%CI = 4.2-13.3), diabetes (RR = 3.7, 95%CI = 1.5-9.4), cardiac insufficiency (RR = 8.4, 95%CI = 5.2-13.6), and morbid obesity (RR = 4.4, 95%CI = 1.8-10.4). Patients who received antiviral treatment within 2 days of symptom onset had shorter hospital stays (mean: 4 days versus 6.5 days, P < 0.05), and the illness tended to become less severe (11.1% versus 19.0%, P = 0.13). CONCLUSIONS: Active research of hospitalized cases enabled almost exhaustive surveillance. The pandemic's hospitalization rates and lethality were more moderate than expected. Some previously known underlying conditions of severity were confirmed during this outbreak. Furthermore, these results show the validity of early antiviral treatment.

OBJECTIVE: To develop a criterion for early detection of bronchiolitis epidemics in Guadeloupe so that prevention and control strategies can be implemented in a more timely manner. METHODS: Weekly figures of bronchiolitis cases reported from July 2005-July 2010 by Guadeloupe's sentinel network were used. The criterion for detecting epidemics was created with data from the 2005-2009 bronchiolitis seasons. First, the baseline level for bronchiolitis (BL) was predicted by fitting a periodic regression on the non-epidemic observations; then a test was conducted of nine possible criteria to define epidemics by combining a statistical threshold set at different levels and a number of consecutive weeks with observations above and below them; lastly, the optimal criterion was selected considering its performances using expert advice as the gold standard. The selected criterion was validated with data from 2009-2010 season. RESULTS: The BL accounted for a linear trend and two sinusoidal functions of 52 and 26 weeks (R2 = 45%). According to the epidemic criterion selected, the statistical threshold was set at the upper limit of the one-sided 95% Confidence Interval of the predicted BL; 2 consecutive weeks with cases above it were necessary to set the start of an epidemic, and three again below to set the end. The median delay in launching the alerts was 2 weeks; there was one false alert; and the sensitivity, specificity, and positive predictive value for detecting epidemic weeks were 98%, 96%, 95%, respectively. During the validation period, the criterion launched one false alert and detected the epidemic with 4 weeks of delay. CONCLUSIONS: This criterion supports epidemiologists in timely interpretation of bronchiolitis epidemiological data for decision makers in Guadeloupe. In the future, it should be updated in accordance with trends in bronchiolitis epidemiology, and improved by integrating virological indicators. Its inclusion in an integrated management strategy for bronchiolitis prevention and control, supported by a bronchiolitis public health network, should also be encouraged.

Sentinel general practitioner networks monitor influenza-like infections (ILI) in Martinique and in Guadeloupe (French West Indies). During the A(H1N1)2009 pandemic, they gave an ILI incidence estimation higher in Martinique than in Guadeloupe. In October 2009, a telephonic survey was launched in both islands to assess the number of ILI diagnoses performed by general practitioners since the beginning of the pandemic. This paper compares the results of sentinel surveillance, of telephonic survey and of hospital surveillance in Guadeloupe and in Martinique.On each island, the sentinel network gathers a representative sample of voluntary general practitioners. Each week, they report the number of ILI they diagnosed the past week. Times series of these weekly numbers were modelized using the Serfling method with the upper limit of the confidence interval of the expected value representing the epidemic threshold. The telephone survey was conducted from October 2, 2009 to October 12, 2009 in Martinique and from October 13, 2009 to October 21, 2009 in Guadeloupe. The quota method was used for sampling individuals older than 14 years, leading to 507 interviews in Guadeloupe and 508 in Martinique.The epidemic lasted 12 weeks in both islands, from August 3 to October 25 in Martinique and from August 17 to November 8 in Guadeloupe. During August and September, estimated attack rate in Martinique was 5.52% (CI95: 5.23-5.83) from the sentinel network versus 8.3% (CI95: 6.0-11.0) from the telephone survey. In Guadeloupe, it was 2.13% (CI95: 1.97-2.24) from the sentinel network versus 6.9% (CI95: 4.8-9.5) from the telephone survey. An equivalent number of confirmed hospitalized cases was observed in the two islands.These results suggest that the sentinel network underestimates ILI incidence in Guadeloupe. According to Emergency Room activity for ILI, it seems possible that ILI incidence was actually higher in Martinique. A lower proportion of swab sampling among ILI hospitalized people could partly explain the observed differences in hospitalization ratio, in severity and in lethality between the two islands.