Relationship between ozone and temperature during the 2003 heat wave in France: consequences for health data analysis

BACKGROUND: PAPRICA is a research program designed to estimate the impact on the health of patients with chronic respiratory insufficiency of a prevention strategy based on notification of ozone pollution. The first year of this study was conducted during the 2003 heat wave, and high temperatures were therefore considered as a confounding factor in the data analysis. The aim of the present study was to assess the relationship between ozone and temperature in order to propose a methodology to distinguish between the effects of ozone and temperature on the impact of a prevention strategy with regard to ozone pollution. METHODS: Multivariate analyses were used to identify associated climate and ozone pollution profiles. This descriptive method is of great value to highlight the complexity of interactions between these parameters. RESULTS: Ozone concentration and temperature were strongly correlated, but the health impact of ozone pollution alone will be evaluated by focusing on situations characterized by ozone concentrations above 110 μg/m(3)/8h (air quality guidelines to protect human health defined by the French legislation) and temperatures lower than 26°C, below the discomfort threshold. CONCLUSION: The precise relationship between ambient ozone concentration and temperature identified during the PAPRICA 2003 study period will be used in analysing the PAPRICA health data

Post-Epidemic Chikungunya Disease on Reunion Island: Course of Rheumatic Manifestations and Associated Factors over a 15-Month Period

Although the acute manifestations of Chikungunya virus (CHIKV) illness are well-documented, few data exist about the long-term rheumatic outcomes of CHIKV-infected patients. We undertook between June and September 2006 a retrospective cohort study aimed at assessing the course of late rheumatic manifestations and investigating potential risk factors associated with the persistence of these rheumatic manifestations over 15 months. 147 participants (>16 yrs) with laboratory-confirmed CHIKV disease diagnosed between March 1 and June 30, 2005, were identified through a surveillance database and interviewed by telephone. At the 15-month-period evaluation after diagnosis, 84 of 147 participants (57%) self-reported rheumatic symptoms. Of these 84 patients, 53 (63%) reported permanent trouble while 31 (37%) had recurrent symptoms. Age ≥45 years (OR = 3.9, 95% CI 1.7–9.7), severe initial joint pain (OR = 4.8, 95% CI 1.9–12.1), and presence of underlying osteoarthritis comorbidity (OR = 2.9, 95% CI 1.1–7.4) were predictors of nonrecovery. Our findings suggest that long-term CHIKV rheumatic manifestations seem to be a frequent underlying post-epidemic condition. Three independent risk factors that may aid in early recognition of patients with the highest risk of presenting prolonged CHIKV illness were identified. Such findings may be particularly useful in the development of future prevention and care strategies for this emerging virus infection

An alternative pathway for alphavirus entry

The study of alphavirus entry has been complicated by an inability to clearly identify a receptor and by experiments which only tangentially and indirectly examine the process, producing results that are difficult to interpret. The mechanism of entry has been widely accepted to be by endocytosis followed by acidification of the endosome resulting in virus membrane-endosome membrane fusion. This mechanism has come under scrutiny as better purification protocols and improved methods of analysis have been brought to the study. Results have been obtained that suggest alphaviruses infect cells directly at the plasma membrane without the involvement of endocytosis, exposure to acid pH, or membrane fusion. In this review we compare the data which support the two models and make the case for an alternative pathway of entry by alphaviruses

Health impacts of the July 2010 heat wave in Québec, Canada

BACKGROUND: One of the consequences of climate change is the increased frequency and intensity of heat waves which can cause serious health impacts. In Québec, July 2010 was marked by an unprecedented heat wave in recent history. The purpose of this study is to estimate certain health impacts of this heat wave. METHODS: The crude daily death and emergency department admission rates during the heat wave were analyzed in relation to comparison periods using 95% confidence intervals. RESULTS: During the heat wave, the crude daily rates showed a significant increase of 33% for deaths and 4% for emergency department admissions in relation to comparison periods. No displacement of mortality was observed over a 60-day horizon. CONCLUSIONS: The all-cause death indicator seems to be sufficiently sensitive and specific for surveillance of exceedences of critical temperature thresholds, which makes it useful for a heat health-watch system. Many public health actions combined with the increased use of air conditioning in recent decades have contributed to a marked reduction in mortality during heat waves. However, an important residual risk remains, which needs to be more vigorously addressed by public health authorities in light of the expected increase in the frequency and severity of heat waves and the aging of the population

[Decision tools for selecting industrial sites where a systematic blood lead screening should be implemented].

International audienceBACKGROUND: Children exposure to lead, even at low doses, can induce neurobehavioral and cognitive effects. In France, a consensus conference about lead poisoning in children has recently stated that exposure near an industrial site was a priority for blood lead screening. Selection criteria for industrial sites have therefore to be defined, especially because screening for lead poisoning requires a blood lead sample, that is an invasive procedure. METHODS: We propose here an operational procedure to select sites where systematic blood lead screenings have to be implemented. It is based on modeling blood lead levels of children aged 1-6 years. This is made by indirect dose estimation from environmental measurements, human exposure parameters and a dose/blood lead level relationship. Decision criteria are based on mean and extreme predicted blood lead level. The procedure is illustrated with a real life smelter case study. RESULTS: For the studied smelter, estimated blood lead levels are less than 100 microg(Pb)/l(blood) and therefore do not lead to recommend a systematic blood lead screening. CONCLUSIONS: Indirect dose estimation associated with blood lead level modeling is a useful tool for selecting where blood lead screenings have to be implemented around industrial sites. Possible improvements of the method are listed

[Decision tools for selecting industrial sites where a systematic blood lead screening should be implemented].

International audienceBACKGROUND: Children exposure to lead, even at low doses, can induce neurobehavioral and cognitive effects. In France, a consensus conference about lead poisoning in children has recently stated that exposure near an industrial site was a priority for blood lead screening. Selection criteria for industrial sites have therefore to be defined, especially because screening for lead poisoning requires a blood lead sample, that is an invasive procedure. METHODS: We propose here an operational procedure to select sites where systematic blood lead screenings have to be implemented. It is based on modeling blood lead levels of children aged 1-6 years. This is made by indirect dose estimation from environmental measurements, human exposure parameters and a dose/blood lead level relationship. Decision criteria are based on mean and extreme predicted blood lead level. The procedure is illustrated with a real life smelter case study. RESULTS: For the studied smelter, estimated blood lead levels are less than 100 microg(Pb)/l(blood) and therefore do not lead to recommend a systematic blood lead screening. CONCLUSIONS: Indirect dose estimation associated with blood lead level modeling is a useful tool for selecting where blood lead screenings have to be implemented around industrial sites. Possible improvements of the method are listed

Outbreak of chikungunya in the French Territories, 2006: lessons learned

On 17 March 2005, the Institut de Veille Sanitaire (InVS) launched an alert about the risk of chikungunya fever to the French territories in the Indian Ocean, based on information about an outbreak on the Comoros from the World Health Organization (WHO).</jats:p