The virus has several highly unusual traits that paint a disquieting picture of a pathogen that may yet lead to a pandemic, according to lead scientists from the National Institute of Allergy and Infectious Diseases. David Morens, Jeffery Taubenberger, and Anthony Fauci, in a paper published in mBio®, the online open-access journal of the American Society for Microbiology, describe the history of H7 viruses in animal and human disease and point out that H7 influenza has a tendency to become established in bird, horse, and swine populations and may spillover repeatedly into humans.
“The evidence as a whole is complex and the implications of past outbreaks for predicting the future course of the current H7N9 epizootic [an epidemic among animals] are uncertain,” write the authors.
The outbreak of H7N9 earlier this year led China to temporarily close scores of live poultry markets in an effort to limit the spread of the virus. Although this previously unrecognized strain of avian influenza A has now been associated with 132 confirmed human infections and 39 related deaths (as of June 14), the rate at which new cases are recognized has dwindled in recent weeks.