著者
Kariwa Hiroaki Fujii Nobuhiro Takashima Ikuo
出版者
The Graduate School of Veterinary Medicine, Hokkaido University
雑誌
Japanese Journal of Veterinary Research (ISSN:00471917)
巻号頁・発行日
vol.52, no.3, pp.105-112, 2004-11

products, a number of other chemical agents, and various physical conditions were evaluated for their ability to inactivate the severe acute respiratory syndrome coronavirus (SARS-CoV). Treatment of SARS-CoV with PVP-I products for 2 min reduced the virus infectivity from 1.17 x 10⁶ TCID₅₀/ml to below the detectable level. The efficacy of 70% ethanol was equivalent to that of PVP-I products. Fixation of SARS-CoV-infected Vero E6 cells with a fixative including formalin, glutaraldehyde, methanol, and acetone for 5 min or longer eliminated all infectivity. Heating the virus at 56℃ for 5 min dramatically reduced the infectivity of the virus from 2.6 x 10⁷ to 40 TCID₅₀/ml, whereas heating the virus for 60 min or longer eliminated all infectivity. Irration with ultraviolet light at 134μQ/cm² for 15 min reduced the infectivity from 3.8 x 10⁷ to 180 TCID₅₀/ml; however, prolonged irradiation (60 min) failed to eliminate the remaining virus, leaving 18.8 TCID₅₀/ml. We beleave that these finding will be useful for the implementation of infection control measures against SARS, and for the establishment of effective guidlines for the preventation of SARS outbreaks.
著者
Jamsransuren Dulamjav Yoshii Kentaro Kariwa Hiroaki Asakawa Mitsuhiko Okuda Kei Fujii Kei Fukumoto Shinya Umemiya-Shirafuji Rika Sasaki Motoki Matsumoto Kotaro Yamaguchi Emi Ogawa Haruko Imai Kunitoshi
出版者
Faculty of Veterinary Medicine, Hokkaido University
雑誌
Japanese Journal of Veterinary Research (ISSN:00471917)
巻号頁・発行日
vol.67, no.2, pp.163-172, 2019-05

The first human case of tick-borne encephalitis (TBE) in Japan was recorded in southern Hokkaido in 1993 and was followed by four further cases in southern, central, and northern Hokkaido during 2016-2018. However, the distribution of TBE virus (TBEV) foci in Japan is unclear. Therefore, here, we serologically examined raccoons (Procyon lotor), sika deer (Cervus nippon), and wild boars (Sus scrofa) as sentinels of TBEV infection in Hokkaido and in Fukushima and Tochigi Prefectures in Honshu. A total of 1,649 serum samples collected between 2003 and 2018 were screened by enzyme-linked immunosorbent assay using subviral particles and confirmed using the virus neutralization test. In raccoons, the seroprevalence of TBEV was 5.9% (39/662 samples) in central Hokkaido in 2003-2005 and 0.8% (3/368 samples) in eastern Hokkaido in 2010-2018, revealing the presence of TBEV foci in these areas. In addition, 0.5% (2/414) of deer sampled in eastern Hokkaido in 2010-2017 and 2.4% (1/42) of deer sampled in Tochigi Prefecture in 2016-2018 were seropositive. On Honshu, seropositive rodents have previously been detected only in Shimane Prefecture. Therefore, the detection of seropositive animals in Tochigi Prefecture may indicate the widespread distribution of TBEV foci throughout Japan. TBEV and viral genes were not detected in 507 ticks collected in the same area of eastern Hokkaido where seropositive animals were found, reemphasizing the value of using serological examination of wild animals as a tool for revealing unknown TBE risk areas. Our findings also indicate that raccoons may be particularly useful sentinels.