Antigenic and genetic characterization of swine influenza A (H1N1) virusesisolated from pneumonia patients in the Netherlands

It is generally believed that pigs can serve as an intermediate host for th e transmission of avian influenza viruses to humans or as mixing vessels fo r the generation of avian-human reassortant viruses. Here we describe the a ntigenic and genetic characterization of two influenza A (H1N1) viruses, wh ich were isolated in The Netherlands from two patients who suffered from pn eumonia. Both viruses proved to be antigenically and genetically similar to avian-like swine influenza A (H1N1) viruses which currently circulate in E uropean pigs. It is concluded that European swine H1N1 viruses can infect h umans directly, causing serious disease without the need for any reassortme nt event, (C) 2001 Academic Press.