tetano
Editor, Senior Moderator
Citation: Richt JA, Rockx B, Ma W, Feldmann F, Safronetz D, et al. (2012) Recently Emerged Swine Influenza A Virus (H2N3) Causes Severe Pneumonia in Cynomolgus Macaques. PLoS ONE 7(7): e39990. doi:10.1371/journal.pone.0039990
Juergen A. Richt1*, Barry Rockx2¤a, Wenjun Ma1, Friederike Feldmann3, David Safronetz2, Andrea Marzi2, Darwyn Kobasa4,6, James E. Strong4,6,7, Lisa Kercher5¤b, Dan Long5, Don Gardner5, Douglas Brining5, Heinz Feldmann2,6*
1 Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America, 2 Laboratory of Virology, Public Health Agency of Canada, Winnipeg, Manitoba, Canada, 3 Office of Operations Management, Public Health Agency of Canada, Winnipeg, Manitoba, Canada, 4 National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada, 5 Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America, 6 Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada, 7 Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
Abstract Top
The triple reassortant H2N3 virus isolated from diseased pigs in the United States in 2006 is pathogenic for certain mammals without prior adaptation and transmits among swine and ferrets. Adaptation, in the H2 hemagglutinin derived from an avian virus, includes the ability to bind to the mammalian receptor, a significant prerequisite for infection of mammals, in particular humans, which poses a big concern for public health. Here we investigated the pathogenic potential of swine H2N3 in Cynomolgus macaques, a surrogate model for human influenza infection. In contrast to human H2N2 virus, which served as a control and largely caused mild pneumonia similar to seasonal influenza A viruses, the swine H2N3 virus was more pathogenic causing severe pneumonia in nonhuman primates. Both viruses replicated in the entire respiratory tract, but only swine H2N3 could be isolated from lung tissue on day 6 post infection. All animals cleared the infection whereas swine H2N3 infected macaques still presented with pathologic changes indicative of chronic pneumonia at day 14 post infection. Swine H2N3 virus was also detected to significantly higher titers in nasal and oral swabs indicating the potential for animal-to-animal transmission. Plasma levels of IL-6, IL-8, MCP-1 and IFNγ were significantly increased in swine H2N3 compared to human H2N2 infected animals supporting the previously published notion of increased IL-6 levels being a potential marker for severe influenza infections. In conclusion, the swine H2N3 virus represents a threat to humans with the potential for causing a larger outbreak in a non-immune or partially immune population. Furthermore, surveillance efforts in farmed pig populations need to become an integral part of any epidemic and pandemic influenza preparedness.
http://www.plosone.org/article/info...0;jsessionid=AF76287A7B35774F313A989CC4B5A6AB
Juergen A. Richt1*, Barry Rockx2¤a, Wenjun Ma1, Friederike Feldmann3, David Safronetz2, Andrea Marzi2, Darwyn Kobasa4,6, James E. Strong4,6,7, Lisa Kercher5¤b, Dan Long5, Don Gardner5, Douglas Brining5, Heinz Feldmann2,6*
1 Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America, 2 Laboratory of Virology, Public Health Agency of Canada, Winnipeg, Manitoba, Canada, 3 Office of Operations Management, Public Health Agency of Canada, Winnipeg, Manitoba, Canada, 4 National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada, 5 Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America, 6 Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada, 7 Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
Abstract Top
The triple reassortant H2N3 virus isolated from diseased pigs in the United States in 2006 is pathogenic for certain mammals without prior adaptation and transmits among swine and ferrets. Adaptation, in the H2 hemagglutinin derived from an avian virus, includes the ability to bind to the mammalian receptor, a significant prerequisite for infection of mammals, in particular humans, which poses a big concern for public health. Here we investigated the pathogenic potential of swine H2N3 in Cynomolgus macaques, a surrogate model for human influenza infection. In contrast to human H2N2 virus, which served as a control and largely caused mild pneumonia similar to seasonal influenza A viruses, the swine H2N3 virus was more pathogenic causing severe pneumonia in nonhuman primates. Both viruses replicated in the entire respiratory tract, but only swine H2N3 could be isolated from lung tissue on day 6 post infection. All animals cleared the infection whereas swine H2N3 infected macaques still presented with pathologic changes indicative of chronic pneumonia at day 14 post infection. Swine H2N3 virus was also detected to significantly higher titers in nasal and oral swabs indicating the potential for animal-to-animal transmission. Plasma levels of IL-6, IL-8, MCP-1 and IFNγ were significantly increased in swine H2N3 compared to human H2N2 infected animals supporting the previously published notion of increased IL-6 levels being a potential marker for severe influenza infections. In conclusion, the swine H2N3 virus represents a threat to humans with the potential for causing a larger outbreak in a non-immune or partially immune population. Furthermore, surveillance efforts in farmed pig populations need to become an integral part of any epidemic and pandemic influenza preparedness.
http://www.plosone.org/article/info...0;jsessionid=AF76287A7B35774F313A989CC4B5A6AB