EID Journal Home > Volume 17, Number 4–April 2011
Volume 17, Number 4–April 2011
Highly Pathogenic Avian Influenza Virus Infection in Feral Raccoons, Japan
Taisuke Horimoto, Ken Maeda, Shin Murakami, Maki Kiso, Kiyoko Iwatsuki-Horimoto, Mariko Sashika, Toshihiro Ito, Kazuo Suzuki, Mayumi Yokoyama, and Yoshihiro Kawaoka
Author affiliations: University of Tokyo, Tokyo, Japan (T. Horimoto, S. Murakami, M. Kiso, K. Iwatsuki-Horimoto, Y. Kawaoka); Yamaguchi University, Yamaguchi, Japan (K. Maeda); Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, Japan (M. Sashika); Tottori University, Tottori, Japan (T. Ito); Hikiiwa Park Center, Wakayama, Japan (K. Suzuki); and Wildlife Management Research Center, Hyogo, Japan (M. Yokoyama)
Suggested citation for this article
Although raccoons (Procyon lotor) are susceptible to influenza viruses, highly pathogenic avian influenza virus (H5N1) infection in these animals has not been reported. We performed a serosurvey of apparently healthy feral raccoons in Japan and found specific antibodies to subtype H5N1 viruses. Feral raccoons may pose a risk to farms and public health.
Although all known subtypes of influenza A virus are maintained in waterfowl, these viruses have also been isolated from various avian and mammalian species. In particular, numerous reports have been made of highly pathogenic avian influenza viruses (H5N1) infecting mammals, causing lethal infections in some species (1,2). Wild mammals could transmit these viruses among other wild and domestic animals, for example, on poultry or pig farms, posing a risk for virus spread and the emergence of mutant viruses. Such viruses could have pandemic potential if they were able to infect humans, thus giving rise to a serious public health concern. Therefore, the continuous monitoring of the exposure of wild mammals to avian influenza viruses, particularly H5N1 viruses, is essential.
Raccoons (Procyon lotor), which belong to the Carnivora, are native to North America. Since the 1970s, a large number of raccoons have been imported as pets into Japan. The release and escape of these animals have resulted in a feral population widely distributed throughout Japan, which continues to increase despite an official eradication program. Recent reports, including serologic surveys and experimental infections, indicate that raccoons can be symptomatically or asymptomatically infected with low pathogenic influenza viruses, such as avian influenza subtype H4N8 or human influenza subtype H3N2 viruses, which they shed for several days, resulting in virus transmission to other raccoons by aerosol (3–5). Such findings present the possibility that wild raccoons could play a role in the transmission of subtype H5N1 viruses in a natural setting. We conducted a serologic survey for subtype H5N1 virus infection in feral raccoons in Japan.
Avian Influenza Virus Infection, Japan | CDC EID
Suggested Citation for this Article
Horimoto T, Maeda K, Murakami S, Kiso M, Iwatsuki-Horimoto K, Sashika M, et al. Highly pathogenic avian influenza virus infection in feral raccoons, Japan. Emerg Infect Dis [serial on the Internet]. 2011 Apr [date cited].
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Taisuke Horimoto, Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; email: firstname.lastname@example.org