Only influenza A viruses infect nonhuman hosts, and a reassortment of genes can occur between those subtypes that typically infect animals and those that infect humans, resulting in antigenic ...

Monthly distribution of influenza A virus subtypes from Jan 2008 to May 2011 and the positive rate in Alberta, Canada. The percentage of positive for IFVA virus subtypes detected from January 2008 ...

as determined by a positive PCR test for influenza and a virus type and subtype consistent with those of the index patient. All household contacts were tested for influenza on or before day 5 ...