大氣中流感與禽流感病毒之偵測

Influenza and Avian Influenza Viurs In Ambient Air

蔡豐達(Feng-Ta Tsai)

指導教授 ： 陳培詩

高雄醫學大學/健康科學院/公共衛生學研究所/碩士(2008年)

摘要

全球暖化與沙漠化情形的惡化，使得亞洲沙塵暴對周圍的國家如韓國、日本、台灣等的影響也日益增加。然而，過去對沙塵暴特性的研究多著重在物理與化學方面，甚少生物方面的研究。在沙塵暴中生物方面的研究中，有關細菌與真菌的研究都指出細菌與真菌有隨著沙塵暴進行長程傳輸的可能性，但在病毒方面的研究目前只有數理模式推估或實驗室內評估，尚無實際大氣環境中採樣分析的研究。
另外，自從SARS過後，中國大陸最令人感到憂心的致病微生物莫過於禽流感病毒，而在禽流感病毒的跨國傳播上，一般認為可能的傳播途徑有家禽或家禽製品的交易、野鳥的交易及候鳥遷徙等。然而，根據世界動物衛生組織(World Organization for Animal Health, OIE)過去的禽流感疫情通報，日本或南韓的禽流感疫情都剛好是發生在亞洲沙塵暴活躍的期間，同時南韓與日本都是會受到亞洲沙塵暴影響的國家，因此懷疑禽流感病毒是否有隨沙塵暴長程傳輸的可能性。
所以，這個研究的主要目的是建立一套可用於大氣中流感與禽流感病毒收集的採樣方法，並搭配Real-time quantitative Polymerase Chain Reaction (Real-time qPCR)這套分子生物技術分析樣品中流感病毒與禽流感病毒之濃度，以期瞭解大氣中於沙塵暴期間與平常日期間流感病毒與禽流感病毒之濃度變化，並探討流感與禽流感病毒與環境因子和類流感病例數之相關。
採樣期間自2006年1月至2008年1月間，分別在萬里、新莊與前金等三個大氣觀測站利用三層濾紙匣，裝載孔徑為1.0 μm且直徑為37 mm之鐵氟龍濾紙，以20 L/min之流量進行採樣。所有環境資料都是直接取自環保署空氣觀測站之資料庫，而類流感病例數來自北部與南部某幾家醫院之急診。
在2006年的結果中，發現萬里與新莊測站的A型流感病毒在疑似沙塵期間的陽性率、病毒濃度與抑制效應都高於平常日，而B型流感病毒在陽性率、病毒濃度與抑制效應的趨勢如同A型流感病毒都是疑似沙塵期間高於平常日，唯獨在萬里測站看到陽性率與病毒濃度是平常日高於疑似沙塵期間。另外，氣流逆軌跡分析之結果顯示疑似沙塵期間的氣流多屬於外來氣流，而平常日之氣流逆軌跡則多屬本土氣流。最後，發現台北市在沙塵期間的類流感病例數高於平常日之類流感病例數。
在相關性檢定方面，看到A型流感病毒與B型流感病毒之陽性反應與沙塵過後的台北市類流感病例數都有顯著的統計相關，顯示疑似沙塵會對台灣民眾造成健康效應。另外，看到平常日之PM10、PM2.5、SO2與A型流感病毒陽性反應呈負相關，顯示這兩環境因子可能會影響分析結果。
在2007年的結果中，完全沒有偵測到A型流感病毒且整年之陽性率較2006年低。由於兩年之間的陽性率差異很大，在比較環境因子的差異後發現PM10與溫度在兩年間有顯著差異。顯示，PM10與溫度可能為所有環境因子中影響最大的兩個變項。

關鍵字

長程傳輸 ； 流感病毒 ； 禽流感病毒

並列摘要

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.

並列關鍵字

long-range transportation ； influenza virus ； avian influenza virus

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