Influenza and Avian Influenza Viurs In Ambient Air

• Main Authors: Feng-Ta Tsai, 蔡豐達
• Other Authors: Pei-Shih Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/78958654957408589493

碩士 === 高雄醫學大學 === 公共衛生學研究所 === 96 === Because of the deterioration of global warming and desertification, the impact of Asian dust storm on nearby countries such as Korea, Japan and Taiwan has become worse. In the previous studies, most of the studies were focus on the analysis of the chemical or physical composition of dust storm. There was relatively few study regarding the biological characteristics of dust storm. Recent studies had showed that bacteria and fungi have the possibility to transport from one country to another during dust storm events. As to virus, there were several studies of mathematics model and laboratory assessments, but there were no environmental sampling and analysis data. After Severe Acute Respiratory Syndrome (SARS), avian influenza is the most considerable disease in China. Normally, the routes for avian influenza virus to transport from country to country were by avian trade or migration birds. However, according to avian influenza outbreak report from World Organization for Animal Health (OIE), outbreaks in Japan and South Korea were occurred during Asian dust storm season. Since Japan and South Korea were both affected by Asian dust storm, we were wondering whether if avian influenza virus can be transported for long distance from one country to another by Asian dust storm. Therefore, the main purpose of this study is to develop a new sampling and analytical method for airborne influenza virus and avian influenza virus quantification by filtration and Real-time quantitative polymerase chain reaction (Real-time qPCR). In addition, virus concentration of dust storm period and normal days was also investigated. Furthermore, the relationship between airborne influenza virus, avian influenza virus, environmental factors and influenza-like illness (ILI) case number were also assessed. Samples were taken at Wan-Li, Xin-Zhuang and Qian-Jin air monitoring stations between January, 2006 and January, 2008. All samples were sampling by Teflon filter with an air flow rate of 20 L/min. Environmental data were provided by Taiwan Environmental Protection Administration, and ILI case data were obtained from several hospitals in Taipei and Kaohsiung. During the first year of this study, we found that the concentration, positive rate and inhibitory effect of influenza A virus were higher during the dust storm period than normal days. The phenomenon were quite the same for influenza B virus, except for concentration and positive rate at Wan-Li air monitoring station. We also found that all the air streams back-trajectory results showed that air stream were more likely came from foreign source during dust storm period and more likely came from native source during normal days. At last, we found that the case number of ILI were higher during dust storm period than normal days at Taipei. For correlation evaluation, the results showed that there was a positive correlation between influenza viruses and ILI case number six days after dust storm and influenza A virus had a negative correlation with both PM10, PM2.5 and SO2. During the second year of this study, there was no positive sample for influenza A virus and the positive rate was quite low. Since the positive rate was quite different between these two years, we compared the environmental factors between these two years. The result showed that PM10 and temperature were significantly different. Therefore, PM10 and temperature might be the main factors that affect virus concentration or detection in environment.