Critically Ill patients with 2009 influenza A(H1N1) in Mexico.

Context: In March 2009, novel 2009 influenza A(H1N1) was first reported in the southwestern United States and Mexico. The population and health care system in Mexico City experienced the first and greatest early burden of critical illness.

Objective: To describe baseline characteristics, treatment, and outcomes of consecutive critically ill patients in Mexico hospitals that treated the majority of such patients with confirmed, probable, or suspected 2009 influenza A(H1N1).