Abai, MR

6th International Congress of DipterologyIs the Japanese blow fly, Calliphora nigribarbis, amechanical carrier of highly pathogenic avian influenzavirus ?Kurahashi, H., T. Hayashi, Y. Tsuda, K. Hoshino, H. Isawa, T. Sasaki, K. Sawabe & M.KobayashiDepartment of Medical Entomology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640 JAPANIn the winter (December 2003 to March 2004), four cases of highlyphathogenic avian influenza (HPAI) were reported from poultry housesand farms in Yamaguchi, Oita and Kyoto Prefectures, western part ofJapan. We entomologists surveyed the first infected poultry farm inTamba-Town, Kyoto, and collecting fly samples on fish baits at sixstations A-F which located 600-2,300m far from the facility. A number ofCalliphora nigribarbis, (Cn) and Aldrichina grahami were observed andcollected on baits, especially at station A. The H5 influenza A virus geneswere detected by RT-PCR from 10-30% samples of both species and theviruses were isolated from 20% (2 positives among 10 examined) of Cnblow flies. The virus isolated was characterized as H5N1 subtype influenzaA virus. Laboratory experiments showed Cn flies ingested carried viruseshaving an infectious titer in their alimentary canales and crops for 24 hunder 20, 70-75% RH.Seasonal migration and characteristic landing of Cn were annuallyobserved in the end of October in Fukuoka, northern Kyushu. A thousandof male and female flies were flying from sea of Genkai-Nada throughFukuoka to the direction of south.Their behavior including short distance migration might be associated withsome of outbreaks in Japan during 2003 to 2004, especially the case of the2nd poultry farm in Tamba which located ca. 2 km far from the first. Amark-release and recapture field experiment showed that female flies canmigrate at least 2-3 km within the same day.In addition to other possibilities such as by wild birds, the blow fly alsoshould be considered a mechanical carrier of HPAI virus.144