Anaerobic bacteremia in the elderly.

Area of Science:

• Infectious Diseases
• Geriatric Medicine
• Critical Care Medicine

Background:

• Anaerobic bacteremia is a serious infection, particularly in elderly individuals.
• Older adults with anaerobic bacteremia often have a higher prevalence of underlying malignancies compared to younger patients.
• Common anaerobic pathogens include the Bacteroides fragilis and Bacteroides melaninogenicus groups, and Clostridium species.

Purpose of the Study:

• To investigate the clinical characteristics and outcomes of anaerobic bacteremia in patients over 60.
• To compare mortality rates based on the presence of underlying malignancy and surgical intervention.
• To identify common anaerobic pathogens and the incidence of polymicrobial infections in this demographic.

Main Methods:

• Retrospective analysis of 68 patients aged over 60 with anaerobic bacteremia at a university hospital.
• Identification of causative anaerobic organisms and assessment of comorbidities, including malignancy.
• Comparison of mortality rates between patients who underwent surgical source removal and those who did not.

Main Results:

• The study identified 68 elderly patients with anaerobic bacteremia.
• Bacteroides fragilis group was the most common isolate (64 isolates), followed by Bacteroides melaninogenicus group (11) and Clostridium species (11).
• Polymicrobial bacteremia occurred in 32.3% of patients. Mortality was 43.3% with surgery versus 81.7% without, and overall mortality was 66.1%.

Conclusions:

• Elderly patients with anaerobic bacteremia have a high mortality rate, significantly increased by underlying malignancy.
• Surgical removal of the anaerobic infection source is associated with a substantial reduction in mortality.
• Prompt surgical management is crucial for improving outcomes in elderly patients with anaerobic bacteremia.