川本 雄也

BACKGROUND: Carbapenem-resistant Gram-negative bacilli (CR-GNB) are a major public health threat, traditionally linked to hospital settings. However, infections are increasingly reported in the community, and the clinical distinctions between community-associated (CA) and healthcare-associated (HA) infections remain unclear. METHODS: We conducted a prospective multicenter study of hospitalized patients with CR-GNB infections across 13 Japanese tertiary hospitals between April 2019 and March 2024. Infections were categorized as CA, HA, or hospital-onset (HO) using standardized criteria. We compared patient demographics, microbiological findings, infection sites, and clinical outcomes based on the setting of onset. RESULTS: Among 425 patients, 43 had CA, 59 HA, and 323 HO infections. Pseudomonas aeruginosa was the predominant pathogen in all groups. Aeromonas species were more frequently associated with CA than HO cases (23.3% of CA vs 2.2% of HO cases), whereas Stenotrophomonas maltophilia was detected almost exclusively among HO cases. Hospital-onset infections were associated with longer median hospital stays compared with CA infections (68 vs 17 days) and a trend toward higher 30-day mortality (23.9% vs 9.5%). In contrast, HA infections demonstrated no significant differences from CA infections in either hospital length of stay (23 vs 17 days) or 30-day mortality rate (10.3% vs 9.5%). CONCLUSIONS: Community-associated CR-GNB infections are an emerging concern in Japan, showing distinct pathogen profiles and infection sites compared to HO cases. Importantly, HA infections resembled CA infections in terms of clinical characteristics and outcomes, suggesting a need to reexamine the clinical relevance of current HA classification criteria for guiding therapy and risk stratification.

INTRODUCTION: Cases of hospital-onset bacteremia and fungemia (HOBF) are on the rise in Japanese hospitals, but little is known about their incidence in hospitals and how it relates to the availability of services provided by infectious diseases departments. METHODS: We herein investigated the monthly incidence density of HOBF per 1,000 patient days from 2013 through 2023 at a tertiary care hospital in Japan. The incidence of overall HOBF and pathogen-specific HOBF, including those caused by Enterobacterales, Staphylococcus aureus, coagulase-negative staphylococci (CNS), and Candida species, was tracked. Changes in the HOBF trend before and after the establishment of an infectious diseases department at the hospital were evaluated. RESULTS: In total, 4,315 HOBF-related events were identified. The overall incidence density of HOBF increased by 2.4-fold from 0.58 per 1,000 PD in 2013 to 1.42 per 1,000 PD in 2023. Both the level and trend changes in the incidence density of overall HOBF (+0.3142 for change in level [P < .001]; +0.0085 for change in trend [P < .001]), HOBF caused by S. aureus (+0.0983 for change in level [P < .001]; +0.0016 for change in trend [P = 0.016]), and Candida spp. (+0.0466 for change in level [P = 0.030]; +0.0019 for change in trend [P = 0.002]) significantly increased after the establishment of the infectious diseases department. CONCLUSION: The incidence density of overall HOBF and clinically important pathogen-specific HOBF increased over the last decade. The availability of services through the infectious diseases department was significantly associated with an increase in the HOBF incidence, likely suggesting improvement in the diagnosis of HOBF.

A man in his 70s was admitted to an intensive care unit with severe COVID-19 and treated with dexamethasone and tocilizumab. After recovery from COVID-19, he developed Clostridium butyricum bacteraemia and non-occlusive mesenteric ischaemia, with fatal outcome. He had been prescribed C. butyricum MIYAIRI 588 fine granules as probiotics for a month. The genome sequences of the C. butyricum isolate from the blood culture and C. butyricum MIYAIRI 588 fine granules were identical by single nucleotide polymorphism analysis. This is the first case of definitive probiotics-related C. butyricum bacteraemia after treatment of severe COVID-19.