Time series analysis of dengue incidence in Guadeloupe, French West Indies: Forecasting models using climate variables as predictors

BACKGROUND: During the last decades, dengue viruses have spread throughout the Americas region, with an increase in the number of severe forms of dengue. The surveillance system in Guadeloupe (French West Indies) is currently operational for the detection of early outbreaks of dengue. The goal of the study was to improve this surveillance system by assessing a modelling tool to predict the occurrence of dengue epidemics few months ahead and thus to help an efficient dengue control. METHODS: The Box-Jenkins approach allowed us to fit a Seasonal Autoregressive Integrated Moving Average (SARIMA) model of dengue incidence from 2000 to 2006 using clinical suspected cases. Then, this model was used for calculating dengue incidence for the year 2007 compared with observed data, using three different approaches: 1 year-ahead, 3 months-ahead and 1 month-ahead. Finally, we assessed the impact of meteorological variables (rainfall, temperature and relative humidity) on the prediction of dengue incidence and outbreaks, incorporating them in the model fitting the best. RESULTS: The 3 months-ahead approach was the most appropriate for an effective and operational public health response, and the most accurate (Root Mean Square Error, RMSE = 0.85). Relative humidity at lag-7 weeks, minimum temperature at lag-5 weeks and average temperature at lag-11 weeks were variables the most positively correlated to dengue incidence in Guadeloupe, meanwhile rainfall was not. The predictive power of SARIMA models was enhanced by the inclusion of climatic variables as external regressors to forecast the year 2007. Temperature significantly affected the model for better dengue incidence forecasting (p-value = 0.03 for minimum temperature lag-5, p-value = 0.02 for average temperature lag-11) but not humidity. Minimum temperature at lag-5 weeks was the best climatic variable for predicting dengue outbreaks (RMSE = 0.72). CONCLUSION: Temperature improves dengue outbreaks forecasts better than humidity and rainfall. SARIMA models using climatic data as independent variables could be easily incorporated into an early (3 months-ahead) and reliably monitoring system of dengue outbreaks. This approach which is practicable for a surveillance system has public health implications in helping the prediction of dengue epidemic and therefore the timely appropriate and efficient implementation of prevention activities

Parallel assessment of male reproductive function in workers and wild rats exposed to pesticides in banana plantations in Guadeloupe

<p>Abstract</p> <p>Background</p> <p>There is increasing evidence that reproductive abnormalities are increasing in frequency in both human population and among wild fauna. This increase is probably related to exposure to toxic contaminants in the environment. The use of sentinel species to raise alarms relating to human reproductive health has been strongly recommended. However, no simultaneous studies at the same site have been carried out in recent decades to evaluate the utility of wild animals for monitoring human reproductive disorders. We carried out a joint study in Guadeloupe assessing the reproductive function of workers exposed to pesticides in banana plantations and of male wild rats living in these plantations.</p> <p>Methods</p> <p>A cross-sectional study was performed to assess semen quality and reproductive hormones in banana workers and in men working in non-agricultural sectors. These reproductive parameters were also assessed in wild rats captured in the plantations and were compared with those in rats from areas not directly polluted by humans.</p> <p>Results</p> <p>No significant difference in sperm characteristics and/or hormones was found between workers exposed and not exposed to pesticide. By contrast, rats captured in the banana plantations had lower testosterone levels and gonadosomatic indices than control rats.</p> <p>Conclusion</p> <p>Wild rats seem to be more sensitive than humans to the effects of pesticide exposure on reproductive health. We conclude that the concept of sentinel species must be carefully validated as the actual nature of exposure may varies between human and wild species as well as the vulnerable time period of exposure and various ecological factors.</p

Une stratégie pour et avec les populations : l’exemple de la lutte contre la dengue

National audienceLa « Stratégie de gestion intégrée pour la prévention et le contrôle de la dengue » est le modèleretenu dans la région des Amériques pour lutter contre cette maladie

La stratégie de gestion intégrée pour la prévention et le contrôle de la dengue dans la région des Amériques : une stratégie pour et avec les populations

National audienc

Maladies à transmission vectorielle : l’expérience des Antilles, un précieux atout pour la France métropolitaine et pour l’Europe

National audienc

Les épisodes de brumes de sable en Guadeloupe: Brumes de sable et croissance fœtale en Grande-Terre et Basse-Terre (Guadeloupe)

National audiencePériodiquement, les Antilles françaises sont touchées par des épisodes de « brumes de sable » constituées de particules fines (inférieures à 10 micromètres) en provenance du Sahara. L’objectif du projet BrumiSaTerre était d’étudier l’association entre l’exposition aux particules fines d’origine saharienne et la croissance fœtale en Guadeloupe et de caractériser les « brumes de sable » sur le plan minéralogique, chimique et microbiologique. Les premières analyses épidémiologiques ont mis en évidence une association entre l’exposition aux « brumes de sable » pendant la grossesse et la prématurité en Guadeloupe

PM10 Chemical Profile during North African Dust Episodes over French West Indies

The French West Indies are periodically affected by North African dust episodes (NADE) resulting in PM10 concentrations exceeding air quality standards. The aim of the present study was to decipher the PM10 chemical profile during NADE over Guadeloupe. PM10 samples were collected daily at a rural site and an urban site during five episodes between April and October in 2017. During these events, the median PM10 mass concentrations were, on average, 2 to 5 times higher than in the post-episode baseline period. Sampled filters were analyzed for their quantification of chemical constituents including carbonaceous fractions (elemental and organic carbon, EC/OC), anions/cations and levoglucosan, 51 elements, and 57 selected organic species. An orthogonal partial least squares discriminant analysis (OPLS-DA) was conducted to identify the specific chemical profile of PM10 during NADE: 16 elements were identified as the most discriminant between the NADE and the control samples with mass concentration levels twice as high during a NADE. Among them, only two (Mn and V) are classified as emerging pollutant while no limit values exist for the other ones. The extensive characterization of the NADE PM10 chemical profile we performed is a key step to assess the chemical exposure of French West Indies populations during such events

Co-exposition aux insecticides et au virus Zika au cours de la grossesse: Impact de la co-exposition aux insecticides et au virus Zika au cours de la grossesse sur le développement neurologique de l’enfant

National audienceEn raison de la co-exposition de la population guadeloupéenne à des arboviroses à tropisme neurologique (comme l’infection à virus Zika) et à des insecticides ayant un potentiel de neurotoxicité, il apparaissait pertinent d’étudier les conséquences d’une exposition conjointe, au cours de la grossesse, à ces agents sur le neuro-développement des enfants

Implication épidémologique du concept "une seule santé"

National audienc