The experiment of whether H5 can ever be successful in human populations is happening before our eyes,” Seema Lakdawala, a flu virologist at Emory University, told me. “And we are doing nothing to stop it.

The first person to have a severe case of H5N1 bird flu in the United States has died, according to the Louisiana Department of Health.

The patient, who was older than 65 and had underlying medical conditions, was hospitalized weeks ago in critical condition with severe respiratory illness.