Results of mosquito inspection on international aircraft, and incidence of invasion of exotic mosquitoes at quarantine ports and airports in Japan (2008-2018).
We report the results of mosquito inspection on international aircraft and in government-run areas by the Japanese Quarantine Station, Ministry of Health, Labour and Welfare between 2008 and 2018. In total, 22,452 aircraft were inspected and 822 adult mosquitoes (including 145 dead mosquitoes) were collected from 240 (1.07%). The majority of the mosquitoes on aircraft belonged to Culex. The most abundant Culex species was Cx. quinquefasciatus and 469 adults were captured. Among them, 398 were collected from aircraft from India. The second-most abundant was Cx. pipiens complex (158 adults) and the third was Cx. gelidus (100 adults). An important invasive dengue vector, Aedes aegypti (2 adults), was captured on an aircraft from the Philippines. In mosquito inspection at government-run areas, the invasion of Ae. aegypti was confirmed at Narita International Airport in 2012, 2013, 2014, 2015, and 2017, Tokyo International Airport (Haneda Airport) in 2013, and Chubu Centrair International Airport (NGO) in 2016 and 2017. Virus detection from the collected mosquitoes revealed Japanese encephalitis virus gene (genotype I, a prevalent genotype in Japan at present) from Cx. tritaeniorhynchus captured at Narita International Airport in 2013, Mikawa Port in 2015, and Kyushu Saga International Airport in 2017.