Dual infection with Pneumocystis carinii and respiratory viruses complicating bone marrow transplantation.

Pneumonia due to dual infection with Pneumocystis carinii and respiratory viruses is a rare but formidable complication of bone marrow transplantation. We report here two cases of viral infections complicating P. carinii pneumonia in bone marrow transplant recipients who, at the time of infection, were not taking P. carinii prophylaxis. Both patients died following the pneumonia. Potential factors contributing to the dual infection included graft-versus-host disease, high-dose steroids and cyclosporin A. P. carinii prophylaxis should be continued for 12 months, or longer in bone marrow transplant recipients requiring prolonged immunosuppressive therapy. As specific antiviral therapy becomes available for some respiratory viral infections, performing regular viral surveillance cultures and responding with active early treatment may help improve the outcome in these immunocompromised patients.