Health status of the swine at the time of sampling in (A) Africa, (B) Asia, (C) Australia, (D) Europe, (E) North America, and (F) South America. The asymptomatic swine were apparently healthy with no clinical symptoms while the symptomatic swine had mild to severe influenza-like disease symptoms. Most of the swine in North America, Australia, Europe, South America, and Africa represented influenza-like illness at sampling while most of the Asian swine were apparently healthy at the time of sampling. It should be noted that asymptomatic cases may not be detected if that was not an aim of the surveillance study. These graphs do not represent the severity of disease as the swine populations and the objectives of surveillances may vary among countries.