Atypical mycobacterium detection in refractory chronic rhinosinusitis

Area of Science:

• Rhinology
• Infectious Diseases
• Microbiology

Background:

• Refractory chronic rhinosinusitis (CRS) management sometimes involves testing for atypical mycobacterium (AM).
• Acid-fast bacilli cultures (AFBC) are used to detect AM in CRS patients, with varying approaches in clinic versus operating room (OR).

Purpose of the Study:

• To evaluate the experience with AM in refractory CRS.
• To identify associated risk factors, species, and culture frequencies.
• To compare targeted AFBC in clinics with customary AFBC in the OR.

Main Methods:

• Retrospective case series with chart review from a tertiary rhinology practice (2005-2011).
• Analysis of patient demographics, medical history, risk factors, AM species, and treatments.
• Statistical comparison of targeted vs. customary AFBC positivity rates.

Main Results:

• Thirty-seven patients had AM-associated CRS; 10 had risk factors (foreign body, immune dysfunction, chemoradiation).
• Most common AM species were Mycobacterium abscessus (57.1%), followed by M. avium-intracellulare complex (14.3%) and M. chelonae (14.3%).
• Targeted AFBC in clinics were positive in 5.3% of cases, compared to 2.6% for customary OR AFBC (P = .12). Macrolide therapy was used in 62% of AM-associated CRS patients.

Conclusions:

• AM-associated CRS is rare and can occur without apparent risk factors.
• Further research is needed on macrolide therapy efficacy and the role of environmental AM exposure (tap water, biofilms, nasal irrigations) in refractory CRS.