Related by context. Frequent words. (Click for all words.) 81 avian flu 77 Bird flu 76 avian influenza 74 bird flu 67 bird flu outbreak 66 bird flu virus 66 H#N# virus 66 H#N# 64 bird flu pandemic 62 H#N# bird flu 62 Bird Flu 62 H#N# strain 61 Swine flu 61 flu pandemic 60 Swine Flu 60 pandemic influenza 60 pandemic 60 pandemic flu 60 swine flu 57 swine flu virus 57 H#N# flu 57 influenza pandemic 57 bird flu outbreaks 56 virus 56 West Nile Virus 56 flu virus 56 H#N# swine flu 56 West Nile virus 56 H#N# influenza 56 influenza 55 mosquito borne disease 55 Rabies 54 Flu 54 H#N# pandemic 54 influenza virus 54 West Nile 54 swine influenza 54 SARS 54 deadly H#N# strain 54 Ebola 53 contagious disease 52 Influenza 52 swine flu pandemic 52 highly contagious 52 SARS virus 52 flu 52 Dengue 51 Severe Acute Respiratory Syndrome 51 outbreak 51 disease 50 WNV 50 poultry 50 flu epidemic 50 influenza viruses 49 dengue 49 CWD 49 Mad cow 49 dengue fever 49 superbug 49 communicable diseases 49 infect humans 49 mad cow disease 48 swine flu epidemic 48 Salmonella 48 Tuberculosis 48 rabies 48 epidemics 48 salmonella 48 infectious disease 48 Lyme disease 47 flu viruses 47 measles 47 communicable disease 47 swine flu outbreak 47 mad cow 47 Ebola virus 47 Outbreaks 47 infectious diseases 47 seasonal influenza 47 cholera 46 pandemics 46 Hepatitis 46 contagious diseases 46 listeria 46 tuberculosis 46 mumps 46 epidemic 45 FMD 45 emerald ash borer 45 Norovirus 45 whooping cough 45 encephalitis 45 seasonal flu 45 migratory birds 45 vCJD 45 outbreaks 45 smallpox 44 Listeria 44 pandemic strain 44 Measles 44 chronic wasting