- 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 47
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
- Tsuyoshi Sekizuka Kentaro Itokawa Masumichi Saito Michitsugu Shimatani Shutoku Matsuyama Hideki Hasegawa Tomoya Saito Makoto Kuroda
- 出版者
- National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee
- 雑誌
- Japanese Journal of Infectious Diseases (ISSN:13446304)
- 巻号頁・発行日
- pp.JJID.2021.844, (Released:2022-02-28)
- 参考文献数
- 12
- 被引用文献数
- 21
Prominent genomic recombination has been observed between the Delta and Alpha variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated from clinical specimens in Japan. Interestingly, the recombination variant detected in this study carries a spike protein identical to the one in the domestic Delta variant, thereby suggesting that further risks would not be concerned with infectivity and immune escape. The recombinant has been classified as XC lineage in the PANGOLIN database. It is necessary to intensively study such marked genetic variations and characterize the emerging variants after careful verification of their lineage and clade assignment.
- 著者
- Kohei Ogawa Osamu Komagata Toshihiko Hayashi Kentaro Itokawa Shigeru Morikawa Kyoko Sawabe Takashi Tomita
- 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.2015.038, (Released:2015-06-12)
- 参考文献数
- 21
- 被引用文献数
- 7
The objective of this study was to clarify the efficacy of a currently-available DEET repellent against tick species in Japan. We performed two different field trials: “human trap,” and “flag-dragging.” In total, 482 ticks were collected from white flannel cloths in field studies. The species of collected ticks consisted of Ixodes persulcatus and I. ovatus which accounted for 5.3 and 94.7% in the human trap test and 31.4 and 68.6% in the flag-dragging test, respectively. The repellency levels of DEET-treated flannel cloths in the human trap and flag-dragging tests were 84.0 and 99.7%, respectively. The escape time of I. persulcatus and I. ovatus female adults from DEET-treated flannel cloth was measured. Median escape times for I. persulcatus and I. ovatus on DEET-treated flannel cloth were 48 s (95% CI: 30–96) and 10 s (95% CI: 5–24), respectively. In contrast, many ticks remained on untreated flannel for 10 min after mounting. These results indicate that DEET repellents appear to prevent tick bites and that the use of DEET repellents against ticks is effective as a personal protective measure.