Public health measures taken at international borders during early  stages of pandemic influenza A (H1N1) 2009: preliminary results.
D003140:Communicable Disease Control / Q000379:methods*; D004196:Disease Outbreaks / Q000517:prevention & control*; D014943:Global Health; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control*; D011795:Surveys and Questionnaires; D014195:Travel