VIROLOGIC INVESTIGATION OF DIFFERENT SUBTYPES OF SWINE INFLUENZA VIRUS INFECTION ON U.S. SWINE FARMS

摘要

In North America, only H1N1 subtype of swine influenza virus (SIV) was known in clinically affected pigs. During 1998, some of the swine farms in Minnesota and Iowa experienced severe respiratory and/or reproductive diseases. These clinical signs werefound to be associated with SIV" H3N2 infection. Subsequently, isolation of H3N2 subtype from clinically affected pigs has been reported in different swine producing states (4.5). In addition, an isolation of H1N2 subtype has been reported from a sample collected in November 1999 during an outbreak of respiratory disease and abortion on an Indiana swine farm (2).