著者
Yoshio Tsuda Yoshihide Maekawa Kohei Ogawa Kentaro Itokawa Osamu Komagata Toshinori Sasaki Haruhiko Isawa Takashi Tomita Kyoko Sawabe
出版者
国立感染症研究所 Japanese Journal of Infectious Diseases 編集委員会
雑誌
Japanese Journal of Infectious Diseases (ISSN:13446304)
巻号頁・発行日
pp.JJID.2014.576, (Released:2015-03-13)
参考文献数
27
被引用文献数
4 48

A total of 160 autochthonous dengue cases transmitted by Aedes albopictus were reported from August to October 2014 in Tokyo Metropolis, Japan. Ae. albopictus is a medically important vector of dengue virus which has been expanding its geographic distribution in temperate regions. The understanding of the distribution and density of biting Ae. albopictus during the dengue outbreak case in Tokyo 2014 is valuable and important to evaluate the epidemic-risk of dengue fever in other highly populated cities in Europe. Of the 160 cases, 134 patients had visited a same park located in central Tokyo, Yoyogi Park. Mosquitoes infected with dengue virus were collected from this park suggesting that the place was the exclusive center of dengue transmission. This study aimed to collect referential data to estimate the transmission threshold of dengue virus in terms of biting density of Ae. albopictus and demonstrated high transmission-risk areas of dengue virus in Yoyogi Park and the vicinity. The overall mean density of biting Ae. albopictus, 7.13/man/8 min, was sufficiently high for successful transmission of dengue virus, and areas with biting densities higher than the overall mean density were classified as high transmission-risk areas of dengue virus in Yoyogi Park.
著者
Shin-ya Ohba Yoshio Tsuda
出版者
The Japan Society of Medical Entomology and Zoology
雑誌
衛生動物 (ISSN:04247086)
巻号頁・発行日
vol.67, no.1, pp.45-50, 2016-03-25 (Released:2016-09-25)
参考文献数
29

The tsunami caused by the Great East Japan Earthquake on March 11, 2011 hit the Pacific coast and caused heavy destruction of natural and man-made environments in north-eastern Japan. This study focuses on mosquito larvae and their potential aquatic insect predators associated with ground pools and pools that appeared in the concrete foundations of destroyed houses (concrete pool) in inundated areas in Miyagi Prefecture, Japan. Field samplings were conducted on late July 2013. Culex inatomii, Cx. pipiens group, Cx. tritaeniorhynchus, and Cx. orientalis were collected from ground pools and concrete pools. The abundance of Cx. inatomii and Cx. pipiens groups in concrete pools was significantly greater than that in the ground pools. A large number of Hydroglyphus japonicus were collected as potential mosquito predators, followed by Micronecta spp., Enochrus japonicus, Rhantus sturalis, Aquarius paludm paludum and Hydrochara affinis, categorized as “flight dispersers,” which might immigrate rapidly from the non-inundated rice fields or wetlands. Stepwise generalized linear models suggested that larval abundance of Cx. inatomii in the pools studied was affected by the vegetation cover and habitat type (ground pool or concrete pool), but not by water depth, salinity, presence of predators, and bottom type (sand or concrete) of aquatic bodies. Concrete pools and covered with dense vegetation provide breeding habitat for Cx. inatomii along with their potential predators.
著者
Momoko TANIGAWA Yukita SATO Hiroko EJIRI Takayuki IMURA Rei CHIBA Hanae YAMAMOTO Makoto KAWAGUCHI Yoshio TSUDA Koichi MURATA Masayoshi YUKAWA
出版者
公益社団法人 日本獣医学会
雑誌
Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日
pp.12-0359, (Released:2012-10-31)
被引用文献数
3 19

We investigated for the first time the prevalence of avian haemosporidia of genera Plasmodium, Haemoproteus, and Leucocytozoon among birds and mosquitoes on Tsushima Island of Japan, which is located between Japan and the Korean Peninsula. Of 55 wild birds belonging to 33 species, 16 (29.1%) tested positive for haemosporidia as follows: Plasmodium spp. (11/55; 20.0%); Haemoproteus spp. (2/55; 3.6%); and Leucocytozoon spp. (3/55; 5.5%). A genetic lineage isolated from the Eurasian Sparrowhawk (Accipiter nisus) was identical to that of the known avian malaria parasite P. circumflexum. Several genetic lineages were identical or closely related to the parasite lineages that were previously detected in birds and mosquitoes in Japan and Korea. Another single identical genetic lineage was also detected in both migratory and resident birds. A total of 753 mosquitoes from 12 species were collected; and one fully fed Aedes albopictus was positive for avian Plasmodium (1/753; 0.13%) which is identical to a genetic lineage detected in both mosquitoes in Japan and birds in Korea. Blood-meal identifications of blood-fed mosquitoes showed direct contact between the mosquitoes and 4 species of mammals including humans, cattle, rodents, and the endangered Tsushima leopard cat (Prionailurus bengalensis euptilura). Migratory birds use Tsushima Island as a site for wintering, breeding, and resting, and our results suggest the transmission of avian haematozoa between resident and migratory birds during their stay on Tsushima Island.