A 73-year-old woman in China has died after contracting an entirely new bird flu virus, researchers from China reported yesterday. The new virus is an H10N8 flu, and this is the first time scientists have seen a human with an N8 flu.
When they analyzed the H10N8 virus’ genes, the researchers found it has characteristics that make it especially severe in people. They also found that another person became ill with the H10N8 virus a little more than a month after the first patient died—which means the infection is circulating. This doesn’t mean there’s an H10N8 epidemic going on, but researchers believe the virus has the potential to spread, they wrote in a paper published today in the journal_ Lancet_. It’s difficult for scientists to predict exactly which viruses will cause epidemics.
The 73-year-old came from Nanchang City in central eastern China. She had high blood pressure, heart disease and a muscular disease called myasthenia gravis, but researchers aren’t sure to what extent those conditions contributed to her death, and to what extent they can blame her flu. In any case, she first came to a hospital with a fever on November 30, 2013, the third day of her flu. Doctors gave her antibiotic and antiviral treatment, but she eventually developed severe pneumonia, septic shock and multiple organ failure. She died December 6.
Researchers hypothesize the virus exchanged genes with flu viruses of the H9N2 type—which normally causes mild illness in people—before making that final jump to humans.
By December 7, researchers had analyzed the genome of her flu and determined it was an H10N8 virus, which doesn’t normally infect humans. But this H10N8 seems to have exchanged genes with other avian flus, so that it has some genes in common with H7N9 and H5N1, which spawned pandemics in Asia. China is still reporting new cases of H7N9, which can be deadly.
From its genetic analysis, the Chinese team hypothesizes that the new H10N8 first arose in wild birds, then found its way to domestic poultry. At that point, the virus exchanged genes with flu viruses of the H9N2 type—which normally causes mild illness in people—before making that final jump to humans.
Researchers still aren’t exactly sure how the Nanchang woman got the flu. Live poultry markets are a hotspot for people to contract bird flus, and the woman had visited one four days before she got sick. When investigators took samples from the market, however, they didn’t see the H10N8 anywhere.
Investigators also tested 17 people close to the woman, including her relatives and her caretakers at the hospital. They were all in the clear.