Legionella maceachernii, previously isolated only from the environment, was shown to be a cause of fatal pneumonia in an immunocompromised patient.

Seroepidemiologic studies of Pneumocystis pneumonia (PCP) in humans have been limited by inadequate reagents. We have developed an enzyme-linked immunosorbent assay (ELISA) using three overlapping recombinant fragments of the human Pneumocystis major surface glycoprotein (MsgA, MsgB, and MsgC) for analysis of antibody responses in HIV-positive patients and healthy blood donors. HIV-positive pat...

Late onset combined immunodeficiency (LOCID) is a recently described variant of common variable immunodeficiency (CVID), involving adult patients presenting with opportunistic infections and/or low CD4+ lymphocyte counts. A 36-year-old male with unremarkable past medical history presented with fever, respiratory failure, and lymphocytopenia. He was found to have Pneumocystis jiroveci pneumonia ...

Pneumocystis jirovecci is an opportunist fungal agent that usually causes pneumonia in immunocompromised patients, particularly those presenting with AIDS. In rare cases, this fungus can cause pneumonia in immunocompetent patients. The symptomatology in this case is acute and fulminant. We report the case of a Pneumocystis jirovecci pneumonia in a young patient initially admitted for acute resp...