Non-viral pathogens of infectious diarrhoea post-allogeneic stem cell transplantation are associated with graft-versus-host disease.

Infectious diarrhoea is common post-allogeneic haematopoietic stem-cell transplantation (alloHSCT). While the epidemiology of Clostridioides difficile infection (CDI) post-alloHSCT has been described, the impact of other diarrhoeal pathogens is uncertain. We reviewed all alloHSCT between 2017 and 2022 at a single large transplant centre; 374 patients were identified and included. The 1-year incidence of infectious diarrhoea was 23%, divided into viral (13/374, 3%), CDI (65/374, 17%) and other bacterial infections (16/374, 4%). There was a significant association between infectious diarrhoea within 1 year post-transplant and the occurrence of severe acute lower gastrointestinal graft-versus-host disease (GVHD, OR = 4.64, 95% CI 2.57-8.38, p < 0.001) and inferior GVHD-free, relapse-free survival on analysis adjusted for age, donor type, stem cell source and T-cell depletion (aHR = 1.64, 95% CI = 1.18-2.27, p = 0.003). When the classes of infectious diarrhoea were compared to no infection, bacterial (OR = 6.38, 95% CI 1.90-21.40, p = 0.003), CDI (OR = 3.80, 95% CI 1.91-7.53, p < 0.001) and multiple infections (OR = 11.16, 95% CI 2.84-43.92, p < 0.001) were all independently associated with a higher risk of severe GI GVHD. Conversely, viral infections were not (OR = 2.98, 95% CI 0.57-15.43, p = 0.20). Non-viral infectious diarrhoea is significantly associated with the development of GVHD. Research to examine whether the prevention of infectious diarrhoea via infection control measures or modulation of the microbiome reduces the incidence of GVHD is needed.

Auditing fungal disease in leukemia patients in a tertiary care center: opportunities and challenges for an antifungal stewardship program.

Invasive fungal disease (IFD) is responsible for significant morbidity and mortality in patients with acute leukemia. Antifungal stewardship (AFS) programs are utilized in this patient group but have been infrequently evaluated in clinical practice. Adults diagnosed with acute leukemia at an Australian tertiary center over two years were identified, with subsequent auditing of IFD prophylaxis and treatment, and identification of further opportunities for AFS activities. Proven or probable IFD occurred in 6% of cases, including 14% of acute lymphoblastic leukemia (ALL) patients and 6% of acute myeloid leukemia (AML) patients. Mold-active antifungal prophylaxis was used in 84% of cases overall, including in 94% of AML cases and 23% of ALL cases. Local auditing identified target areas for AFS in this complex patient cohort, including modification of clinical guidelines, enhanced patient screening, improved access to fungal diagnostics and therapeutic drug monitoring, and the establishment of a specialized, embedded AFS program.