H5 and H9 subtypes of Avian Influenza Viruses are Real Threat To Humans / 감염과화학요법

ABSTRACT

Recent outbreaks of H5N1 avian influenza viruses in most Asian countries alert the imminent pandemic. Twenty-three humans out of 34 confirmed cases were dead of H5N1 infections. H9N2 avian influenza viruses are widespread in poultry in most Asian countries and infected humans in 1999 and 2003. H9N2 or H5N1 influenza viruses may cause a next pandemic. The extensive surveillance in poultry and pigs are very important for predicting a next pandemic. We performed the surveillance of avian influenza viruses in chickens sold in the live poultry markets. Only H9N2 subtypes of influenza viruses were isolated from chickens in the Korean live bird markets. Serological surveillance in chickens showed that chickens were infected with over 50% with H9N2 viruses. Antigenic analysis showed that current circulating H9N2 influenza viruses are distinct from those of Hong Kong and 1996 Korean isolates from chicken farms. Serological surveillance of pigs against H9N2 influenza viruses showed that over 20% are positive. To prepare the vaccine of H5N1 avian influenza viruses, reassortant viruses were made using the available reverse genetics. The efficacy and safety test of H5N1 candidate vaccine in monkeys showed that neutralization antibody were induced and no side effects such as fever and weight loss were observed.