Superficial mycobacterial lymphadenitis in Saskatchewan

Area of Science:

• Infectious Diseases
• Microbiology
• Public Health

Background:

• Superficial mycobacterial lymphadenitis presents a diagnostic challenge.
• Accurate etiological identification is essential for appropriate treatment strategies.

Purpose of the Study:

• To analyze the epidemiological and clinical characteristics of mycobacterial lymphadenitis in Saskatchewan.
• To differentiate between cases caused by Mycobacterium tuberculosis and nontuberculous mycobacteria.

Main Methods:

• Retrospective review of bacteriologically verified cases of superficial mycobacterial lymphadenitis.
• Analysis of patient demographics, geographical distribution, and causative agents.
• Comparison of diagnostic smear positivity rates between tuberculous and nontuberculous infections.

Main Results:

• 35 of 43 cases (81%) were caused by Mycobacterium tuberculosis; 8 cases (19%) by nontuberculous mycobacteria, primarily M. avium-intracellulare.
• Tuberculous lymphadenitis was more common in adult females (North American Indian or Asian-born), affecting cervical nodes.
• Nontuberculous mycobacterial lymphadenitis occurred more frequently in female white children, involving submandibular nodes.
• Acid-fast bacilli smears were more sensitive in nontuberculous cases (88%) than in tuberculous cases (46%).

Conclusions:

• Mycobacterium tuberculosis is the leading cause of superficial mycobacterial lymphadenitis in Saskatchewan.
• Distinct demographic and clinical patterns exist for tuberculous versus nontuberculous mycobacterial lymphadenitis.
• Distinguishing the causative mycobacterial species is vital for guiding treatment and public health interventions.