Listeroisis in immunosuppressed patients. A cluster of eight cases.

Bactermia due to listeria monocytogenes developed in eight patients who were receiving immunosuppresive medications during a 15 month period at one hospital. Seven survived. Meningitis was documented in only the four who received kidney transplants. Their neurologic signs were minimal, indicating a need to treat any immunosuppressed patient with Listeria bacteremia for meningitis. During this period the incidence of Listeria bactermia in immunosuppressed patients greatly exceeded that previously observed in this hospital or reported elsewhere, but the incidence of infection with other opportunistic agents was not increased. As with previously decreased listeria outbreaks in nonimmunosuppressed patients, no source or mechanism of spread could be identified. Thus, disease due to L. monocytogenes may occur focally among immunosuppressed populations, a pattern which also appears to be emerging for other opportunistic agents. A patient's exposure to different opportunistic agents may be as important as the kind of immunosuppressive therapy he recieves in determining which opportunistic infection he will acquire or even whether any infection will occur.