臺灣地區蚊媒病毒之監測與特性分析

Surveillance and Characterization of Mosquito-borne Viruses in Taiwan

蘇千玲(Chien-Ling Su)

指導教授 ： 蔡坤憲

國立臺灣大學/公共衛生學院/公共衛生碩士學位學程/碩士(2017年)

https://doi.org/10.6342/NTU201700915

摘要

日本腦炎、登革熱和茲卡病毒感染症是在臺灣疾病管制署列為通報的蚊媒性傳染病。其中，日本腦炎病毒感染發生在大多數亞洲國家也包括臺灣在內，此病毒是亞洲地區最常見的腦炎主因。根據過去文獻紀錄，近幾年日本腦炎病毒的基因型別已由原來的第三型轉變成基因型第一型。登革熱是登革病毒所引起，為臺灣最常見的蚊媒性疾病，在臺灣主要是因為通過密切的商業聯繫與不斷輸入鄰近東南亞國家的登革病毒，致使臺灣每年都會有大大小小不同的的疫情發生，由於每年的流行株序列不同，可以證實登革熱並非地方性流行病。自從2005年以來，茲卡病毒感染症疫情已發生在65個國家，主要是亞洲和美洲地區，多數被茲卡病毒感染的人是沒有症狀的，但有少部分的人症狀卻非常嚴重，在臺灣2016年共有13例境外移入茲卡感染症個案。本研究於2016年期間，於臺灣北中南東區，以乾冰掛網結合捕蚊器和人工掃網進行蚊蟲採集，採集之成蚊先進行型態分類，並進行蚊媒病毒的檢測和特性分析。在本研究中，利用螢光定量反轉錄聚合酶連鎖反應方法，使用廣用性的引子組來檢測病媒蚊感染病毒情況。使用之引子組涵蓋黃病毒科、套膜病毒科、呼腸病毒科和布尼亞病毒科。篩檢結果顯示：在臺灣的養豬場、公園和水鳥棲息地被採集到的成蚊共有19種，總計22,042隻蚊蟲，分成572池，其中三斑家蚊是豬場和濕地中最常見的蚊種。黃病毒螢光定量反轉錄聚合酶連鎖反應檢測顯示共有99池為陽性，這些陽性池的蚊種計有三斑家蚊 (81池)、環蚊家蚊 (3池)、白頭家蚊 (1池)、中華瘧蚊 (6池)、熱帶家蚊 (1池)、白腹叢蚊 (1池)和地下家蚊 (6池)。病毒檢驗陽性檢體經成功培養和定序分析後，培養確認有日本腦炎病毒 (67池)與家蚊黃病毒 (5池)。日本腦炎病毒E基因定序及演化親緣性分析顯示：2016年分離到的所有日本腦炎病毒株均屬於基因型第一型，臺灣日本腦炎病毒分離株與中國大陸、越南、日本的日本腦炎病毒株的親緣關係最為接近。由於氣候變遷加劇，臺灣地區未來也可能發生登革熱、日本腦炎、茲卡病毒及其他蚊媒病毒傳染病的共同流行，政府應更加強病媒性傳染病監測，成立病媒性傳染病研究及防治中心，並配合實驗室為基礎的檢驗系統，有系統的進行各種病媒性病毒的監測、檢驗與流行病學研究，以降低病媒傳染病的發生。

關鍵字

監測 ； 蚊媒病毒 ； 日本腦炎病毒 ； 定量反轉錄聚合酶連鎖反應 ； 三斑家蚊

並列摘要

Japanese encephalitis, dengue fever and Zika virus (ZIKV) infection are reported as notified of mosquito-borne infectious diseases in Taiwan's CDC. Japanese encephalitis virus (JEV) infection occurs throughout most of Asian countries including Taiwan and is the most common cause of encephalitis in that region. The literature indicated that JEV strains had shifted from GIII to GI over the past years. Dengue fever is caused by dengue virus, the most common mosquito-borne disease in Taiwan. Mainly because through close business ties with neighboring countries in Southeast Asia continue to enter the dengue virus, resulting in Taiwan every year there are different sizes of outbreak, due to the annual sequence of different strains, it was confirmed that dengue is not endemic. ZIKV outbreaks have occurred in 65 countries, mainly in Asia and the America, since 2015. Most people with ZIKV infection have no symptoms or mild disease. In Taiwan, there were 13 imported ZIKA cases in 2016. During the period of 2016, mosquitoes were collected and collected by integrate binding dry ice hanging mosquito nets and sweeping net in Taiwan. The mosquitoes were collected and the mosquito-borne virus was monitored and analyzed. In this study, we developed multiple real-time fluorescence quantitative RT-PCR using virus Genus (or group) consensus primer sets to detect flavivirdae, togaviridae, reoviridae and bunyavirdae. The results showed that there were 19 species of mosquitoes collected in a wide range of pig farms, parks and waterbirds habitats in Taiwan, with a total number of 22,042 mosquitoes divided into 572 pools. Cx. tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. A total number of 99 tested positive for flavivirus by RT-PCR, including Cx. tritaeniorhynchus (n=81), Cx. annulus (n=3), Cx. fuscocephala (n=1), Anopheles sinensis (n=6), Cx. quinquefasciatus (n=1), Armigeres subalbatus (n=1), and Cx. pipiens molestus (n=6). All the mosquito pools were extracted for virus isolation and were proved as JEV (67 pools) and Culex flavivirus (5 pools). Phylogenetic analysis indicated that all the JEV strains isolated in 2016 belong to genotype I. The phylogenetic analysis of JEV isolates from Taiwan showed a high correlation with JEV isolates from China, Vietnam and Japan. As the climate change intensifies, the future of Taiwan may suffer from dengue fever, Japanese encephalitis, ZIKV and other mosquito-borne infectious diseases, the Government should put more effort on surveillance of infectious diseases, and invest more resource to establish mosquito-borne infectious disease research and prevention center. It is expected to control the mosquito-borne diseases with the infrastructure of laboratory-based inspection system surveillance, diagnosis, as well as epidemiological analysis.

並列關鍵字

surveillance ； mosquito-borne viruses ； Japanese encephalitis virus ； quantitative RT-PCR ； Cx. tritaeniorhynchus

參考文獻

2.Boom AK, Lindsay MD, Wright AE, et al. Epizootic activity of Murray Valley encephalitis and Kunjin viruses in an aboriginal community in the southeast Kimberley region of Western Australia: results of mosquito fauna and virus isolation studies. Am J Trop Med Hyg. 2003; 69: 277-283.

3.Center for Disease Control. Epidemic/Epizootic West Nile Virus in the United States: Guidelines for surveillance, prevention, and control. 2013, 15pp.

6.Gubler DJ. The global emergence/resurgence of arboviral diseases as public health problems. Arch Med Res. 2002; 33(4): 330-342.

7.Knox J, Cowan RU, Doyle JS, et al. Murray Valley encephalitis: a review of clinical features, diagnosis and treatment. Med J Aust. 2012; 196: 322-6.

8.Haddow AD, Schuh AJ, Yasuda CY, et al. Genetic characterization of Zika virus strains: geographic expansion of the Asian lineage. PLoS Negl Trop Dis. 2012; 6: e1477.