Outbreak of highly pathogenic avian influenza in Japan and anti-influenza virus activity of povidone-iodine products.
OBJECTIVE
On January 12, 2004, an outbreak of highly pathogenic avian influenza, caused by the H5N1 strain, occurred in a one-layer flock in Yamaguchi Prefecture, Japan. It had been 79 years since the last outbreak of avian influenza was confirmed in Japan. By February, 3 additional outbreaks had occurred (1 in Oita Prefecture and 2 in Kyoto Prefecture). Influenza viruses are enveloped viruses and are relatively sensitive to inactivation by lipid solvents, such as detergents. Infectivity is also rapidly destroyed by ether, sodium hypochlorite, povidone-iodine (PVP-I), peracetic acid and alcohol. However, these antiviral effects were only tested against human influenza A viruses. In the present study, the antiviral activity of PVP-I products against H5, H7 and H9 avian influenza A viruses, which had recently been transmitted to humans, were investigated.


METHODS
The in vitro antiviral activity of PVP-I products (2% PVP-I solution, 0.5% PVP-I scrub, 0.25% PVP-I palm, 0.23% PVP-I gargle, 0.23% PVP-I throat spray and 2% PVP-I solution for animals) against avian influenza A viruses [a highly pathogenic avian influenza virus, A/crow/Kyoto/T2/04 (H5N1; 10(6.5) EID(50)/0.1 ml), and 3 low pathogenic avian influenza A viruses, A/whistling swan/Shimane/499/838 (H5N3; 10(4.8) EID(50)/0.1 ml), A/whistling swan/Shimane/42/80 (H7N7; 10(5.5) EID(50)/0.1 ml) and A/duck/Hokkaido/26/99 (H9N2; 10(4.8) EID(50)/0.1 ml)] were investigated using embryonated hen's eggs.


CONCLUSIONS
Viral infectious titers were reduced to levels below the detection limits by incubation for only 10 s with the PVP-I products used in this study. These results indicate that PVP-I products have virucidal activity against avian influenza A viruses. Therefore, the PVP-I products are useful in the prevention and control of human infection by avian influenza A viruses.
Department of Veterinary Public Health, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
Hiroshi
H
Ito
Toshihiro
T
Ito
Muneo
M
Hikida
Junko
J
Yashiro
Akira
A
Otsuka
Hiroshi
H
Kida
Koichi
K
Otsuki
D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D000998:Antiviral Agents / Q000494:pharmacology*; D001208:Asia / Q000453:epidemiology; D002642:Chick Embryo; D002645:Chickens; D004196:Disease Outbreaks / Q000517:prevention & control / Q000662:veterinary; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects; D053126:Influenza A Virus, H7N7 Subtype / Q000187:drug effects; D053127:Influenza A Virus, H9N2 Subtype / Q000187:drug effects; D009980:Influenza A virus / Q000187:drug effects*; D005585:Influenza in Birds / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D007251:Influenza, Human / Q000517:prevention & control* / Q000635:transmission / Q000821:virology; D007564:Japan / Q000453:epidemiology; D009426:Netherlands / Q000453:epidemiology; D011206:Povidone-Iodine / Q000494:pharmacology*
D000891:Anti-Infective Agents, Local; D000998:Antiviral Agents; D011206:Povidone-Iodine