Assertion: flu's illness | /r/CreatedBy | other viruses
Facets:
Source sentences:
text: It's often used to describe an illness caused by other viruses.
text: This action was a reflection of the spread of the new H1N1 virus, not the severity of illness caused by the virus.
text: The illness caused by the influenza virus tends to be worse than illnesses caused by other viruses which cause a flu-like illness.