Decline in temperature and humidity increases the occurrence of influenza in cold climate

Environmental Health

Research

Kari Jaakkola¹  Thedi Ziegler²  Esa Rönkkö²  Raija Juvonen³  Annika Saukkoriipi⁴  Tiina M Ikäheimo⁵  Jouni JK Jaakkola⁶  Jari Jokelainen⁷  Jaana Kauppila⁸  Olli Vainio⁹ 

[1] Centre for Military Medicine, the Finnish Defence Forces, P.O. Box 2, FI-17701, Lahti, Finland;Center for Environmental and Respiratory Health Research, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;Department of Infectious Disease Surveillance and Control, National Influenza Center, National Institute for Health and Welfare, P.O. Box 30, FI-00271, Helsinki, Finland;Department of Otorhinolaryngology, Kainuu Central Hospital, Sotkamontie 13, FI-87140, Kajaani, Finland;Department of Vaccinations and Immune Protection, National Institute for Health and Welfare, P.O. Box 310, FI-90101, Oulu, Finland;Institute of Health Sciences, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;Center for Environmental and Respiratory Health Research, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;Medical Research Center Oulu, Oulu, Finland;Institute of Health Sciences, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;Center for Environmental and Respiratory Health Research, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;Respiratory Medicine Unit, Department of Medicine, Oulu University Hospital, P.O.Box 20, FI-90029, Oulu, Finland;Medical Research Center Oulu, Oulu, Finland;Institute of Health Sciences, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;Unit of General Practice, Oulu University Hospital, P.O. Box 20, FI-90029, Oulu, Finland;Northern Finland Laboratory Centre (NordLab), Oulu, Finland;Northern Finland Laboratory Centre (NordLab), Oulu, Finland;Institute of Diagnostics, Department of Microbiology and Immunology, University of Oulu, P.O. Box 5000, FI-90014, Oulu, Finland;

关键词: Influenza;    Low temperature;    Absolute humidity;   

DOI  :  10.1186/1476-069X-13-22

 received in 2013-11-07, accepted in 2014-03-20,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundBoth temperature and humidity may independently or jointly contribute to the risk of influenza infections. We examined the relations between the level and decrease of temperature, humidity and the risk of influenza A and B virus infections in a subarctic climate.MethodsWe conducted a case-crossover study among military conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training period and identified 66 influenza A and B cases by PCR or serology. Meteorological data such as measures of average and decline in ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods, prior and after the onset were obtained.ResultsThe average temperature preceding the influenza onset was −6.8 ± 5.6°C and AH 3.1 ± 1.3 g/m3. A decrease in both temperature and AH during the hazard period increased the occurrence of influenza so that a 1°C decrease in temperature and 0.5 g decrease per m3 in AH increased the estimated risk by 11% [OR 1.11 (1.03 to 1.20)] and 58% [OR 1.58 (1.28 to 1.96)], respectively. The occurrence of influenza infections was positively associated with both the average temperature [OR 1.10 per 1°C (95% confidence interval 1.02 to 1.19)] and AH [OR 1.25 per g/m3 (1.05 to 1.49)] during the hazard period prior to onset.ConclusionOur results demonstrate that a decrease rather than low temperature and humidity per se during the preceding three days increase the risk of influenza episodes in a cold climate.

【 授权许可】

Unknown   
© Jaakkola et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.