SUMMARY: In April 2005, an outbreak of Chikungunya fever occurred on the island of Réunion in the Indian Ocean. During winter 2005, six patients developed meningoencephalitis and acute hepatitis due to Chikungunya virus. Our objectives were to determine the incidence and mortality of atypical Chikungunya viral infections and to identify risk factors for severe disease. A hospital-based surveillance system was established to collect data on atypical Chikungunya cases. Case reports, medical records and laboratory results were reviewed and analysed. We defined an atypical case as one in which a patient with laboratory-confirmed Chikungunya virus infection developed symptoms other than fever and arthralgia. We defined a severe atypical case as one which required maintenance of at least one vital function. We recorded 610 atypical cases of Chikungunya fever: 222 were severe cases, 65 affected patients died. Five hundred and forty-six cases had underlying medical conditions (of which 226 suffered from cardiovascular, 147 from neurological and 150 from respiratory disorders). Clinical features that had never been associated with Chikungunya fever were recorded, such as bullous dermatosis, pneumonia, and diabetes mellitus. Hypertension, and underlying respiratory or cardiological conditions were independent risk factors for disease severity. The overall mortality rate was 10·6% and it increased with age. This is the first time that severe cases and deaths due to Chikungunya fever have been documented. The information presented in this article may assist clinicians in identifying the disease, selecting the treatment strategy, and anticipating the course of illness.

In January 2005, an epidemic of chikungunya fever broke out in the Comoro Islands and lasted until May 2005. In April, cases were also reported in Mayotte and Mauritius. On Réunion Island, the first cases were reported at the end of April. Surveillance of this epidemic required an adaptive system, which at first was based on active and retrospective case detection around the cases reported, then relied on a sentinel network when the incidence increased. Emerging and severe forms of infection were investigated. Death certificates were monitored. By April 2006, the surveillance estimate was 244,000 cases of chikungunya virus infection, including 123 severe cases and 41 of maternoneonatal transmission, with an overall attack rate of 35%. Chikungunya infection was mentioned on 203 death certificates and significant mortality was observed. This epidemic highlighted the need for a mutual strategy of providing information on arboviral diseases and their prevention and control between countries in the southwestern Indian Ocean.

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.

BACKGROUND: A study was undertaken to assess the combined association between urban air pollution and emergency admissions for asthma during the years 1986-92 in Barcelona, Helsinki, Paris and London. METHODS: Daily counts were made of asthma admissions and visits to the emergency room in adults (age range 15-64 years) and children (< 15 years). Covariates were short term fluctuations in temperature and humidity, viral epidemics, day of the week effects, and seasonal and secular trends. Estimates from all the cities were obtained for the entire period and separately by warm or cold seasons using Poisson time-series regression models. Combined associations were estimated using meta-analysis techniques. RESULTS: Daily admissions for asthma in adults increased significantly with increasing ambient levels of nitrogen dioxide (NO2) (relative risk (RR) per 50 micrograms/m3 increase 1.029, 95% CI 1.003 to 1.055) and non-significantly with particles measured as black smoke (RR 1.021, 95% CI 0.985 to 1.059). The association between asthma admissions and ozone (O3) was heterogeneous among cities. In children, daily admissions increased significantly with sulphur dioxide (SO2) (RR 1.075, 95% CI 1.026 to 1.126) and non-significantly with black smoke (RR 1.030, 95% CI 0.979 to 1.084) and NO2, though the latter only in cold seasons (RR 1.080, 95% CI 1.025 to 1.140). No association was observed for O3. The associations between asthma admissions and NO2 in adults and SO2 in children were independent of black smoke. CONCLUSIONS: The evidence of an association between air pollution at current urban levels and emergency room visits for asthma has been extended to Europe. In addition to particles, NO2 and SO2--by themselves or as a constituent of a pollution mixture--may be important in asthma exacerbations in European cities.

Residents living close to agricultural lands might be exposed to pesticides through non-occupational pathways including spray drift and volatilization of pesticides beyond the treated area. This review aimed to identify and analyze scientific literature measuring pesticide exposure in non-farmworker residents living close to agricultural lands, and to suggest practical implications and needs for future studies. A review was performed using inclusion criteria to identify original articles of interest published between 2003 and 2018. From the 29 articles selected in this review, 2 belonged to the same study and were grouped, resulting in a total of 27 studies. Seven studies assessed exposure to pesticides using environmental samples, 13 collected biological samples and 7 analyzed both. Nine studies included a reference group of residents living far from agricultural lands while 11 assessed the influence of the spraying season or spray events on pesticide exposures. Studies included in this review provide evidence that residents living near to agricultural lands are exposed to higher levels of pesticides than residents living further away. This review highlights that the following study design characteristics may be more appropriate than others to measure pesticide spray drift exposure in non-farmworker residents living close to agricultural lands: inclusion of a non-agricultural control group, collection of both biological and environmental samples with repeated sampling, measurements at different periods of the year, selection of numerous study sites related to one specific crop group, and measurements of pesticides which are specific to agricultural use. However, few studies to date incorporate all these characteristics. Additional studies are needed to comprehensively measure non-occupational pesticide exposures in this population in order to evaluate health risks, and to develop appropriate prevention strategies.