Influenza A viruses possesses two virion surface glycoproteins including haemagglutinin (HA) and neuraminidase (NA). The NA plays an important role in viral replication and promotes virus release from infected cells and facilitates virus spread throughout the body. To find out any genomic changes that might be occurred on NA gene of avian influenza circulating viruses, we have genetically analy...

953 S from one influenza season to the next, we have lost the use of our leading antiviral influenza drug because of resistance. This winter, the circulating strain of seasonal influenza A virus (H1N1) is resistant to the neuraminidase inhibitor osel tamivir. Moreover, rather than emerging under selective pressure of drug use, as many antibiotic-resistant bacteria do and as has been the concern...

OBJECTIVES We characterized human H1N1 influenza isolate A/Hokkaido/15/02, which has haemagglutinin and neuraminidase mutations that reduce drug susceptibility to oseltamivir, zanamivir and peramivir. METHODS One wild-type and three mutant viruses were isolated by plaque purification. Viruses were tested in MUNANA-based enzyme assays, cell culture and receptor binding assays. RESULTS Two vi...

N Engl J Med 2005;353:1363-73. Copyright © 2005 Massachusetts Medical Society. he impact of influenza infection is felt globally each year when the disease develops in approximately 20 percent of the world’s population. In the United States, influenza infections occur in epidemics each winter, generally between late December and early March. Recent events, including human cases of avian influen...

In a recent study, we found neuraminidase activity to be present in only 7 of 15 cultures of various types and strains of laboratory-adapted Diplococcus pneumoniae (R. T. Kelly, D. Greiff, and S. Farmer, J. Bacteriol. 91:601, 1966). To determine whether a correlation existed between the presence of neuraminidase activity in pneumococci and human pneumococcal illness, we have studied freshly iso...