Why You Shouldn’t Worry About Catching Bird Flu from a Person … Yet

It’s far from comforting to hear that, according to a new study, the new H7N9 strain of bird flu has been passed from person to person for the first time. The finding has sparked some scary headlines. "First study of human transmission of new bird flu raises worries," Reuters reports. "Chinese bird flu may be spreading between people," adds the Guardian. But before you buy surgical masks in bulk and retreat to your sanitized basement evacuation shelter, consider that the authors of the scientific study, published Tuesday in the British Medical Journal, went out of their way to point out that the finding is not cause for too much alarm …yet.

H7N9, the new strain of avian influenza, or "bird flu," was first reported on April 1 in China. So far, 134 people are confirmed to have caught it, and 43 have died. Severe pneumonia and other respiratory problems are common symptoms.

To determine whether the virus had spread from person to person, the British Medical Journal study examined a 60-year-old man in Wuxi, China, near Shanghai, who contracted the virus after shopping at live poultry markets. His daughter, 32, had no exposure to poultry, but caught the virus after caring for her father in the hospital. Analysis of the strains found in both the father and the daughter showed they were genetically almost identical, further indicating that H7N9 had passed between the two.

A deadly virus, in other words, appears to have spread between humans. But it might not be as bad as it sounds. Delve deeper into the study, and you’ll find that the daughter was by her sick father’s side for six to eight hours a day for a week, and had the rather unpleasant task of cleaning up his "oral secretions" without any protective equipment. The researchers tested all 43 other people who came into close contact with the father at least once a day — many of them hospital workers — and none of them had gotten sick. And it wasn’t just because they were extra-careful medical professionals. The subjects stayed bird flu-free despite taking protective measures the authors call "relatively weak" such as using common surgical masks rather than special filtering masks. Even the son-in-law, who, like the daughter, provided bedside care without any protection, did not get sick. That situation suggests that having a genetic connection, as the father and daughter did but not the son-in-law, is an important factor in the virus’s spread.

To review: What we know now is that it’s possible for the new strain of bird flu to spread from one person to another person who is constantly by the former’s bedside without protection, cleaning up his oral secretions, and biologically related to him — not quite I Am Legend levels yet. As the authors put it, "The virus has not gained the ability for efficient sustained transmission from person to person."

Still, the finding that the virus can transmit from person to person at all does indicate that it could be something to worry about in the future. "Our findings reinforce that the novel virus possesses the potential for pandemic spread," the researchers warn.

For now, the key word in there is "potential."