Emerg Infect Dis Journal Volume 17, Number 2–February 2011Possible increased pathogenicity of pandemic (H1N1) 2009 influenza virus upon reassortment.
Eefje J.A. Schrauwen, Sander Herfst, Salin Chutinimitkul, Theo M. Bestebroer, Guus F. Rimmelzwaan,
Albert D.M.E. Osterhaus, Thijs Kuiken, and Ron A.M. Fouchier. Author affiliation: National Influenza Centre and Erasmus Medical Center Department of Virology, Rotterdam, the NetherlandsAbstract
Since emergence of the pandemic (H1N1) 2009 virus in April 2009, three influenza A viruses—seasonal (H3N2), seasonal (H1N1), and pandemic (H1N1) 2009—have circulated in humans. Genetic reassortment between these viruses could result in enhanced pathogenicity. We compared 4 reassortant viruses with favorable in vitro replication properties with the wild-type pandemic (H1N1) 2009 virus with respect to replication kinetics in vitro and pathogenicity and transmission in ferrets. Pandemic (H1N1) 2009 viruses containing basic polymerase 2 alone or in combination with acidic polymerase of seasonal (H1N1) virus were attenuated in ferrets. In contrast, pandemic (H1N1) 2009 with neuraminidase of seasonal (H3N2) virus resulted in increased virus replication and more severe pulmonary lesions. The data show that pandemic (H1N1) 2009 virus has the potential to reassort with seasonal influenza viruses, which may result in increased pathogenicity while it maintains the capacity of transmission through aerosols or respiratory droplets.
Schrauwen EJA, Herfst S, Chutinimitkul S, Bestebroer TM, Rimmelzwaan GF, Osterhaus ADME, et al. Possible increased pathogenicity of pandemic (H1N1) 2009 influenza virus upon reassortment.Emerg Infect Dis
[serial on the Internet]. 2011 Feb [date cited]. ttp://www.cdc.gov/EID/content/17/2/200.htm