Jpn. J. Infect. Dis., 60 (1), 53-54, 2007

To see a printable version of the article in the Adobe file format, click this [PDF] link.

Short Communication

High Incidence of Amantadine-Resistant Influenza AH3 Viruses Isolated during the 2005-2006 Winter Season in Nara, Japan

Masaki Yoneda*, Yumiko Inoue and Yoshiteru Kitahori

Virology and Bacteriology Division, Nara Prefectural Institute for Hygiene and Environment, Nara 630-8131, Japan

(Received September 14, 2006. Accepted October 27, 2006)


*Corresponding author: Mailing address: Virology and Bacteriology Division, Nara Prefectural Institute for Hygiene and Environment, 57-6 Ohmori-cho, Nara city, Nara 630-8131, Japan. Tel: +81-742-20-2887, Fax: +81-742-27-0634, E-mail: mk.yoneda@ihe.pref.nara.jp


SUMMARY: We examined the incidence of amantadine-resistant influenza AH3 viruses isolated in Nara Prefecture during the 2005-06 winter season. The genetic analyses of the M2 ion channel protein were conducted using reverse transcriptase PCR and direct sequencing. Thirteen out of 18 (72.2%) strains were identified as amantadine-resistant, and this incidence was remarkably higher than those previously recored in Nara Prefecture. Genetic analyses of the viruses revealed that all the anti-drug strains contained a change at position 31 (AGT→AAT, Ser31Asn) in the M2 gene. One of the 13 amantadine-resistant strains also contained a change at position 27 (GTT→GCT, Val27Ala). Our data indicate that there has been a significant increase of drug-resistant influenza AH3 viruses in Nara Prefecture, and raise concern about the spread of resistant influenza AH3 viruses in Japan.


Go to JJID Homepage

Go to JJID 60 (1) Contents