Study shows songbirds might aid in H7N9 spread

H7N9 avian flu replicates well in finches, sparrows, and parakeets experimentally inoculated with the pathogen, and the birds shed the virus in high numbers and show few signs of disease, scientists reported today in Emerging Infectious Diseases.

Researchers from St. Jude Children's Research Hospital in Memphis, Tenn., and from China and Hong Kong inoculated groups of zebra finches, society finches, parakeets, and house sparrows with the H7N9 virus either intranasally, intraocularly, or orally and housed them with birds that were not inoculated (contact birds).

All inoculated birds shed virus, but only via the beak and not via the cloaca (anus). Shedding levels were highest in the two finch species, which shed virus for 6 days. Parakeets also shed virus for 6 days, while the sparrows shed virus for 4 days.

All species of birds were susceptible to H7N9 infection, but only one sparrow showed signs of clinical disease: lethargy, loose and discolored feces, and ruffled feathers.

Contact finches and sparrows showed evidence of H7N9 infection, but only one infected contact finch shed high levels of the virus. The contact parakeets did not become infected.

The authors conclude, "Our demonstration that parakeets and multiple species of songbirds are susceptible to influenza A(H7N9) virus isolated from humans during the recent outbreak in China further supports the possible contribution of songbirds and parakeets to the ecology, maintenance, and transmission of novel A(H7N9) viruses."
Jan 24 Emerg Infect Dis study

Historian says 1918 pandemic may have begun in China

The "Spanish flu" pandemic of 1918 may actually have originated in China, a Canadian historian who took a multidisciplinary look at the evidence—including new data from UK and Canadian archives—suggests in the current issue of War in History.

Mark Osborne Humphries of Memorial University of Newfoundland says that the transport of 96,000 Chinese laborers to work behind British and French lines in World War I may have ignited the deadly strain of H1N1 influenza to spread around the world.

Humphries found archival evidence that a respiratory illness that struck Shanxi province in northern China in November 1917 was identified in 1918 by Chinese officials as identical to pandemic influenza. He also found records showing that more than 3,000 of the 25,000 Chinese workers who were transported across Canada starting in 1917 in sealed railcars en route to Europe were placed in medical isolation, many with flu-like symptoms.

Previous reports have noted a lower incidence of 1918 pandemic flu in China, which would seem to support Humphries's contention, in that some immunity may have been conferred in the Chinese population from earlier exposure to the virus, National Geographic reported yesterday.

Historians had mixed reviews of the paper, according to National Geographic. "This is about as close to a smoking gun as a historian is going to get," said historian James Higgins of Lehigh University in Bethlehem, Pa. "These records answer a lot of questions about the pandemic."

But Jeffery Taubenberger, MD, PhD, chief of viral pathogenesis and evolution at the National Institute of Allergy and Infectious Diseases, was more cautious. "I'm not sure if this question can ever be fully answered," he said, pointing out that even the precise origin of the 2009 H1N1 pandemic remains uncertain.
January War in History abstract
Jan 23 National Geographic report