Is daily exposure to ozone associated with respiratory morbidity and lung function in a representative sample of schoolchildren? Results from a panel study in Greece.

Previous time series or panel studies of asthmatics have reported respiratory health effects following short-term exposure to ozone (O3). We followed 186 children aged 10 years old in Athens and Thessaloniki, Greece for 5 weeks during the academic year 2013-2014 and recorded daily their respiratory symptoms, absenteeism and peak expiratory flow (PEF). We applied mixed models controlling for various possible confounders to investigate the daily associations between O3 exposure - derived from weekly personal and fixed school site measurements calibrated using daily values of the fixed monitoring site nearest to the child's school location - and PEF, presence of any symptom, cough and stuffy nose, as well as absenteeism. We tested the robustness of our findings to varying modeling assumptions and confounders and investigated effect modification patterns by medication use, time spent outdoors and prevalence of asthma. A 10 µg/m3 increase in O3 personal exposure was associated with increased odds of any symptom (odds ratio (OR): 1.19, 95% confidence interval (CI): 0.98, 1.44), largely attributed to the increase in the odds of stuffy nose (OR: 1.23, 95% CI: 1.00, 1.51). PEF and absenteeism were not related to O3 exposure. Our results were robust to several sensitivity analyses. Effects were modified by medication use as presence of symptoms but also decreases in PEF were mainly reported among non-users, while our effect estimates were not driven by the asthmatic subgroup of children. Our findings indicate that short-term O3 exposure may be associated with respiratory symptoms extending previously reported results for asthmatics to the general population.

Laboratory and surveillance studies following a suspected Dengue case in Greece, 2012.

OBJECTIVES: To describe the laboratory assays used to investigate a suspected dengue case in summer 2012 in western Greece and to report the public health response. DESIGN OF METHODS: Samples from the patient were tested for detection of Dengue virus (DENV) antibodies, NS1 antigen and RNA. Public health professionals interviewed residents of the village, and blood samples taken from 132 persons were tested for antibodies for DENV and West Nile virus (WNV). Samples from 10 persons who reported symptoms in the prior 15 days (including 3 persons who had fever at the time of sampling) were tested for DENV, WNV and additional arboviruses. Entomological missions were organized in the area of potential exposure to investigate the presence of competent DENV vectors. RESULTS: Based on a combination of serological and molecular methods, DENV infection was excluded, and the problems in the serology, especially in the DENV NS1 antigen, were attributed to interfering factors. A 6.1% WNV seroprevalence was detected in the region, and phlebovirus IgM and IgG antibodies were detected in two of three persons who had fever at the time of sampling. Aedes albopictus adult mosquitoes were present in the region. CONCLUSIONS: A multi-disciplinary field and laboratory investigation showed no evidence of DENV infection. There is a need for industries to improve the immunometric assays to avoid interference with rheumatoid or other factors, and increased awareness is needed for the evaluation of the diagnostic assays. The high WNV seroprevalence in the investigated region highlights the need for strengthening awareness on vector borne diseases. The presence of Ae. albopictus suggests that the possibility of introduction of DENV exists, and preparedness plans are needed.