More unidentified illnesses linked to unexplained bird flu case in Missouri Ars TechnicaPossible Cluster of Human Bird-Flu Infections Expands in Missouri The New York TimesMore health-care workers in contact with Missouri bird flu patient report respiratory symptoms CNNFour more health workers show symptoms after contact with Missouri bird flu patient ReutersSecond symptomatic health worker reported in Missouri’s H5N1 probe University of Minnesota Twin Cities