Elizabethkingia bloodstream infections in severely immunocompromised patients: persistent, relapsing and associated with high mortality.

Objectives: Elizabethkingia species are uncommon causes of bloodstream infections, representing a true opportunistic and multi-drug-resistant pathogen to immunocompromised or vulnerable hosts. Despite this, data are lacking regarding optimal management strategy for infections with this organism, which is associated with significant mortality and morbidity. We describe patient characteristics, management and outcomes in this case series.

Patients and methods: All inpatients at the Royal Brisbane and Women's Hospital with a positive blood culture for Elizabethkingia spp. were identified by database query. Clinical information including medical history, source of infection, attempts at source control and outcome were collected. Laboratory data including duration of bacteraemia and antimicrobial susceptibility testing were also collected.

Results: All patients had severe defects of innate and adaptive immunity. Targeted therapy was started promptly and efforts at source identification and control were appropriately pursued. Despite this, outcomes were generally poor. A previously unrecognized presentation of relapsing infection was described in one case, requiring long-term suppressive antimicrobials to control. One case died as a result of infection and one case was cured, but died soon after due to complications of immunosuppression.

Conclusions: Treatment of these organisms is challenging due to limited effective therapy, development of on treatment resistance and profound host immunocompromise. Up-front use of multiple, optimally dosed antimicrobials, attempting source control and attempting to restore host immune function all appear to be key to achieving good outcomes.