Both people who died of swine flu in the United States had pre-existing health problems, federal health authorities said Thursday in a report. The 22-month-old child who died April 27 of the flu, also called H1N1, had neonatal myasthenia gravis, an autoimmune disease, said the report, which was written by a virus investigation team at the Centers for Disease Control and Prevention and published online in the New England Journal of Medicine. The child — who was from Mexico and who fell ill while visiting relatives in Texas — also had a heart defect, problems swallowing and chronic hypoxia, the report said
