Although the reasons are not clear, there is a clear association of C. septicum septicemia and carcinoma of the colon or cecum, carcinoma of the breast, and hematological malignancies (a high percentage of cases of invasive disease is associated with hematologic malignancy). Distant myonecrosis is the most lethal form of C. septicum infection. C. septicum infections are not closely linked with immunosuppression or cell-mediated immunity. Further investigation for any of these underlying conditions is necessary whenever C. septicum is identified in blood cultures.
Furthermore, each of the following species of anaerobes should be identified when recovered from clinically significant sites:
- Anaerobic cocci - Many strains are resistant to both clindamycin and metronidazole, antibiotics often given empirically for anaerobic infections.
- Bacteroides fragilis - It tends to be virulent and resistant to penicillin.
- Clostridium perfringens - Because of its association with rapidly progressive myonecrosis and gangrene.
- C. septicum - Because it is often related to carcinoma of the colon.