Related by context. Frequent words. (Click for all words.) 67 flu 64 flu virus 63 H#N# virus 60 viral infection 60 virus 57 influenza 57 swine flu 56 H#N# 55 Flu 55 H#N# flu 55 illness 54 Swine Flu 53 swine flu virus 52 Influenza 51 groin injury 51 sprained ankle 51 Swine flu 50 rib injury 50 swine flu outbreak 50 bronchitis 50 hamstring injury 49 bacterial infection 49 calf strain 49 influenza virus 49 calf injury 49 H#N# strain 48 whooping cough 48 groin strain 48 sore throat 48 bird flu virus 48 bug 48 avian flu 48 ankle injury 47 avian influenza 47 colds 47 MRSA 47 hamstring strain 47 soreness 47 thigh injury 47 meningitis 46 SARS 46 bird flu 46 strained hamstring 46 infection 46 knee injury 46 jet lag 46 sickness 46 seasonal flu 45 sore shoulder 45 highly contagious 45 ailment 44 ankle sprain 44 pneumonia 44 concussion 44 sprained knee 44 West Nile virus 43 bedbugs 43 dengue fever 43 Bird flu 43 measles 42 West Nile Virus 42 dengue 42 germs 42 bone bruise 42 West Nile 42 tendinitis 42 injury 42 viruses 41 fungus 41 Lyme disease 41 hepatitis 40 Injuries 40 bacterium 40 flu pandemic 40 contagious 40 pandemic flu 39 hamstring 39 outbreak 39 pandemic 39 ligament damage 39 sprain 39 infectious disease 39 cold snap 39 Sars 39 tuberculosis 39 Virus 39 cholera 38 TB 38 rabies 38 bacteria 38 infections 38 E. coli 38 absences 38 illnesses 38 groin 38 spasms 38 SARS outbreak 37 diarrhea 37 malaise 37 lice 37 malaria