Epidemiologic Investigation of a Cluster of Neuroinvasive Bacillus cereus Infections in 5 Patients With Acute Myelogenous Leukemia. (1st July 2015)

• Record Type: Journal Article
• Authors: Rhee, Chanu; Klompas, Michael; Tamburini, Fiona B.; Fremin, Brayon J.; Chea, Nora; Epstein, Lauren; Halpin, Alison Laufer; Guh, Alice; Gallen, Rachel; Coulliette, Angela; Gee, Jay; Hsieh, Candace; Desjardins, Christopher A.; Pedamullu, Chandra Sekhar; DeAngelo, Daniel J.; Manzo, Veronica E.; Folkerth, Rebecca Dunn; Milner, Danny A.; Pecora, Nicole; Osborne, Matthew; Chalifoux-Judge, Diane; Bhatt, Ami S.; Yokoe, Deborah S.
• Is Part Of: Open forum infectious diseases. Volume 2:Number 3(2015)
• Publication Date: 2015-07-01
• Subjects: acute myelogenous leukemia -- Bacillus cereus -- central nervous system infection -- infection control investigation; Communicable diseases -- Periodicals; Medical microbiology -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.1093/ofid/ofv096
• Languages: English
• ISSNs: 2328-8957

Abstract

Abstract: Background. Five neuroinvasive Bacillus cereus infections (4 fatal) occurred in hospitalized patients with acute myelogenous leukemia (AML) during a 9-month period, prompting an investigation by infection control and public health officials. Methods. Medical records of case-patients were reviewed and a matched case-control study was performed. Infection control practices were observed. Multiple environmental, food, and medication samples common to AML patients were cultured. Multilocus sequence typing was performed for case and environmental B cereus isolates. Results. All 5 case-patients received chemotherapy and had early-onset neutropenic fevers that resolved with empiric antibiotics. Fever recurred at a median of 17 days (range, 9–20) with headaches and abrupt neurological deterioration. Case-patients had B cereus identified in central nervous system (CNS) samples by (1) polymerase chain reaction or culture or (2) bacilli seen on CNS pathology stains with high-grade B cereus bacteremia. Two case-patients also had colonic ulcers with abundant bacilli on autopsy. No infection control breaches were observed. On case-control analysis, bananas were the only significant exposure shared by all 5 case-patients (odds ratio, 9.3; P = .04). Five environmental or food isolates tested positive for B cereus, including a homogenized banana peel isolate and the shelf of a kitchen cart where bananas were stored. Multilocus sequence typing confirmed that all case and environmental strains were genetically distinct. Multilocus sequence typing-based phylogenetic analysis revealed that the organisms clustered in 2 separate clades. Conclusions. The investigation of this neuroinvasive B cereus cluster did not identify a single point source but was suggestive of a possible dietary exposure. Our experience underscores the potential virulence of B cereus in immunocompromised hosts.