title: Swine flu--hard to keep up with new developments.
mesh_terms: D004196:Disease Outbreaks / Q000517:prevention & control*; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D017410:Practice Guidelines as Topic; D011314:Preventive Health Services; D014481:United States