Viridans streptococcal shock in bone marrow transplantation patients

We have recognized a rapidly progressive, often fatal shock syndrome associated with viridans streptococcal sepsis following bone marrow transplantation (BMT). Of 832 patients receiving a marrow transplant at the University of Minnesota between 1976 and 1988, including 123 with viridans streptococcal bacteremia, 10 patients (8%) developed clinical shock within an average of 2 days (range 0-4 days) of their first positive blood culture. Viridans streptococcal shock occurred in patients early in the transplantation course, between 1 and 28 (median 6) days following BMT when all 10 patients were neutropenic. Six of the 10 patients died as a consequence of their shock or from subsequent complications. The most frequent (6 of 10 patients) viridans streptococcal species isolated in the shock patients was Streptococcus mitis. Of multiple factors analyzed for increased risk of developing viridans streptococcal shock, only younger patient age was significantly associated with the development of shock. Although 58% of BMT recipients with viridans streptococcal bacteremia were younger than 15 years, all 10 patients comprising the shock population were < 15 years of age (P < 0.02). We speculate that certain streptococcal strains may trigger fulminant shock in the immunocompromised BMT patient.