Update on 2009 pandemic influenza A (H1N1) virus

The pandemic of a novel strain of swine-origin influenza A (H1N1) is expected to make this a difficult flu season. Fortunately, this strain is relatively mild, and the principles of prevention, diagnosis, and treatment remain the same. Physicians will have a number of complex decisions to make about when to test, when to treat, and when to simply reassure.