2009 H1N1 Influenza in HIV-Positive Patients

During the 2009 H1N1 influenza pandemic, many people were concerned that HIV-positive patients might be at particularly high risk for severe disease and adverse outcomes. In a prospective investigation conducted at 13 hospitals in Spain between June and November 2009, researchers studied the clinical presentation and prognosis of adults who were admitted with confirmed H1N1 influenza. Among 585 patients enrolled, 26 were known to be HIV positive; the others were presumed to be HIV negative but were not systematically tested.

The HIV-positive patients generally had well-controlled disease: 89% were taking potent combination antiretroviral therapy, 84% had an undetectable viral load, and the median CD4 count was 503 cells/mm³. The HIV-positive…