Introducing ciprofloxacin to their institution’s empiric antimicrobial regimen for patients with AML and prolonged or recurrent neutropenic fevers appeared to reduce the risk of Bacillus cereus infection.
Bacillus cereus can lead to serious invasive infections, neurological complications, and even death in immunocompromised patients. A new case series highlights the risk for patients with acute myeloid leukemia (AML) and persistent neutropenic fever and explains one strategy to reduce the potential harm.
The report was published in Open Forum Infectious Diseases.
B cereus—a gram-positive, rod-shaped bacterium—is ubiquitous, noted the study authors from at Brigham and Woman’s Hospital in Boston. For patients with AML or neutropenia, the bacterium can cause sepsis and neuroinvasive disease, leading to complications that include meningoencephalitis, brain abscess, and cerebral hemorrhage. Even with timely antimicrobial therapy, neuroinvasive B cereus is often fatal, the authors added.
Due to B cereus’ β-lactamase production, infection from the bacterium cannot be treated with β-lactam therapy, they noted.
“Recommended therapies are vancomycin, carbapenems, or fluoroquinolones, although isolates resistant to each of these antimicrobial classes have been reported,” Little and colleagues noted.
One challenge with B cereus is that it can be difficult to trace cases back to a single point of origin. For instance, the report’s authors said they experienced a cluster of neuroinvasive B cereus infections in 2013 and 2014. Although they could not identify a clear source, “there was evidence linking cases to Bacillus contamination of unpeeled banana associated with nearby construction. In response to the cluster, their health system stepped up their cleaning practices and temporarily changed their protocols for fever and neutropenia, including adding empiric ciprofloxacin therapy for patients with AML who were receiving induction chemotherapy and had persistent or recurrent neutropenic fever.
“Following the discontinuation of these measures, 3 patients with AML developed health care–associated neuroinvasive B cereus infections in close temporal proximity in 2022, triggering an extensive epidemiologic investigation that identified 2 additional cases between 2018 and 2022,” the authors said.
The new report describes their experience with those cases. The new case series had similar characteristics to the 2013-2014 cluster. In each case between 2018 and 2022, the patient was undergoing induction chemotherapy and had neutropenia, and all experienced neurological symptoms, although the investigators said they did not have microbiologic confirmation of B cereus in the central nervous system (CNS). They added, however, that the timing of the CNS complications—occurring a median of 1 day after diagnosis—was “highly suggestive of neuroinvasive disease.”
All 5 patients survived after treatment with ciprofloxacin “with limited or no neurologic sequelae.”
The authors said they were unable to pinpoint a point source for the cases. Like in the earlier cluster, they added ciprofloxacin to their empiric antimicrobial regimen for patients with similar characteristics, and as of 1 year after the change, there had been no new cases.
The authors said early identification of B cereus is important but can be difficult in patients with profound neutropenia or thrombocytopenia.
“In fact, the clinical association of neurologic events with invasive B cereus infection has primarily been described through postmortem studies,” they wrote. “For patients who survive, B cereus is often identified only on blood culture, as was the case in this series.”
Therefore, they said, clinicians treating immunocompromised patients with B cereus bloodstream infections should be vigilant about the potential for neurologic complications.
“These infections may be underrecognized, and even though they have been associated with nosocomial outbreaks, due to the ubiquity of B cereus, they can also occur as sporadic infections associated with independent environmental or dietary exposures,” they wrote.
The investigators concluded that physicians may reduce the risk of morbidity by deploying antimicrobials, but they added that they should limit such use to high-risk patients given the broader concerns about antimicrobial resistance.
Reference
Little JS, Coughlin C, Hsieh C, et al. Neuroinvasive Bacillus cereus infection in immunocompromised hosts: epidemiologic investigation of 5 patients with acute myeloid leukemia. Open Forum Infect Dis. 2024;11(3):ofae048. doi:10.1093/ofid/ofae048
Real-World Data Show Sotorasib Effective for NSCLC With KRAS Mutation
May 18th 2024Data from real-world and clinical-trial settings on frontline monotherapy treatment with the KRAS inhibitor sotorasib both show similar progression-free survivals and a high likelihood that the treatment’s efficacy is not affected with dose reduction.
Read More
CMS Medicare Final Rule: Advancing Benefits, Competition, and Consumer Protection
May 7th 2024On this episode of Managed Care Cast, we're talking with Karen Iapoce, senior director of government products and programs at ZeOmega, about the recent CMS final rule on Medicare Part D and Medicare Advantage.
Listen
Study Highlights Significant Increases in Utilization, Spending on DMD Drugs in Medicaid
May 17th 2024The findings add to recent research on the growing utilization, expenditure, and prices of Duchenne muscular dystrophy (DMD) therapies in the current landscape, an area health care policy could potentially address.
Read More
Perioperative Nivolumab Boosts NSCLC Survival: CheckMate 77T Trial
May 16th 2024This interim analysis of the CheckMate 77T trial, outcomes were compared between adult patients receiving neoadjuvant nivolumab plus chemotherapy or neoadjuvant chemotherapy plus placebo for resectable non–small cell lung cancer (NSCLC).
Read More
ATS 2024: Bridging the Past, Present, and Future of Respiratory Care
May 16th 2024The application of artificial intelligence in medicine is anticipated as a highlight of ATS 2024, with sessions exploring its applications in research, radiological interpretation, and pediatric pulmonology.
Read More