INFLUENZA-A IN IMMUNOCOMPROMISED PATIENTS

Immunocompromised patients with influenza A were identified in Stockho lm during two influenza seasons. The predominant subtypes were H3N2 du ring 1988-1989 and H1N1 during 1990-1991. The median age of the 25 pat ients was 43 years (range, 3-80 years). Twelve patients had received r enal transplants and had ongoing immunosuppression. Seven patients had received bone marrow transplants between 2 days and 3 years before be coming infected with influenza virus A. Two patients were in an aplast ic phase, and four had chronic graft-versus-host disease with ongoing immunosuppression. Six patients had hematologic malignancies. Two of t he 25 patients had severe infections. One of these infections occurred in a bone marrow transplant recipient during an aplastic phase and wa s fatal; the other affected a patient who had received a renal transpl ant. One bone marrow transplant patient had mild but protracted infect ion. The remaining 22 patients had mild influenza A. We conclude that influenza A in immunocompromised patients occasionally causes severe c omplications but in most patients is mild and self-limiting.