Mycobacterium fortuitum bacteraemia in an immunocompromised patient

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Hematology

Background:

• Immunocompromised patients, particularly those with hematologic malignancies like acute lymphoblastic leukemia (ALL) undergoing chemotherapy, are susceptible to opportunistic infections.
• Rapidly growing mycobacteria (RGM) are an emerging cause of infection, often associated with healthcare settings and invasive devices.
• Mycobacterium fortuitum is an RGM that can cause severe disseminated infections in immunocompromised individuals.

Observation:

• A case of Mycobacterium fortuitum bacteremia was identified in an immunocompromised patient with ALL receiving intensive chemotherapy.
• The probable source of infection was a peripherally inserted vascular catheter, confirmed by four positive serial blood cultures.
• The patient presented with fever and signs of systemic infection.

Findings:

• The isolated Mycobacterium fortuitum strain demonstrated sensitivity to amikacin and clarithromycin.
• Following treatment with amikacin and clarithromycin, and removal of the central vascular catheter, the patient's fever resolved.
• Repeat blood cultures became negative, indicating successful eradication of the bacteremia.

Implications:

• This case underscores the importance of considering RGM infections, such as Mycobacterium fortuitum, in immunocompromised patients, especially when routine cultures are negative.
• Early diagnosis and appropriate antimicrobial therapy, combined with source control (e.g., catheter removal), are crucial for favorable outcomes.
• Healthcare providers should maintain a high index of suspicion for RGM in patients with malignancy and invasive devices presenting with persistent fever or unexplained infections.