The impact of altitude on hospitalization and hospital mortality from pandemic 2009 influenza A (H1N1) virus pneumonia in Mexico.

OBJECTIVE

To determine the effect of altitude of residence on influenza A (H1N1).

MATERIALS AND

METHODS

We analyzed 207 135 officially notified of influenza-like illness (ILI) cases, 23 048 hospitalizations and 573 deaths during the first months of the novel pandemic influenza A H1N1 virus, to examine if residents of high altitude had more frequently these adverse outcomes.

RESULTS

Adjusted rates for hospitalization and hospital mortality rates increased with altitude, probably due to hypoxemia.