An influenza A (H1N1) virus, closely related to swine influenza virus, responsible for a fatal case of human influenza

Abstract

, an influenza A virus, designated A/Maryland/12/91 (A/MD), was isolated from the bronchial secretions of a 27-year-old animal caretaker. He had been admitted to the hospital with bilateral pneumonia and died of acute respiratory distress syndrome 13 days later. Antigenic analyses with postinfection ferret antisera and monoclonal antibodies to recent Hi swine hemagglutinins indicated that the hemagglutinin of this virus was antigenically related to, but distinguishable from, those of other influenza A (HlNl) viruses currently circulating in swine. Oligonucleotide mapping of total viral RNAs revealed differences between A/MD and other contemporary swine viruses. However, partial sequencing of each RNA segment of A/MD demonstrated that all segments were related to those of currently circulating swine viruses. Sequence analysis of the entire hemagglutinin, nucleoprotein, and matrix genes of A/MD revealed a high level of identity with other contemporary swine viruses. Our studies on A/MD emphasize that HlNl viruses in pigs obviously continue to cross species barriers and infect humans.

Emerging Respiratory Viruses: Challenges and Vaccine Strategies

“…Human-swine reassortant viruses have been detected in pigs in Japan, Europe, and the United States, demonstrating that genetic reassortment can occur in nature between influenza A viruses in pigs, but these resulting reassortants have not yet resulted in an epidemic virus strain in humans (162). While swine influenza viruses have been sporadically transmitted to humans, none of these incidents has resulted in an epidemic disease in humans (35,39,54,55,60,78,81,98,155,193,201,225).…”

Genetic and antigenic analysis of epidemic influenza viruses isolated during 2006–2007 season in Taiwan

“…RT-PCR reactions were performed according to previous publications [Wentworth et al, 1994;Daum et al, 2002Daum et al, , 2005Townsend et al, 2006] using a Perkin Elmer 2700 thermocycler (Applied Biosystems, Forest City, CA). The PCR product was purified using QIAquick spin columns using the manufacturer's protocols (Qiagen, Valencia, CA).…”

Antigenic and Genetic Characterization of Swine Influenza A (H1N1) Viruses Isolated from Pneumonia Patients in The Netherlands

“…Several reports on the transmission of "classical" swine H1N1 viruses, which predominantly circulate in the United States, to humans illustrate the latter possibility. In some cases, human infections with these swine influenza viruses proved to be fatal (Gaydos et al, 1977;Patriarca et al, 1984;Wells et al, 1991;Wentworth et al, 1994). Besides classical swine influenza A viruses, also avian-like swine influenza A (H1N1) viruses, prevalent in Europe since 1979 (Donatelli et al, 1991;Scholtissek et al, 1983;Campitelli et al, 1997) have been shown to be transmitted to humans (De Jong et al, 1986, 1988.…”