Nontuberculous mycobacteria in cervical lymphadenopathies of HIV positive and HIV-negative adults

Background: Tuberculosis is a global public health problem, especially in emerging countries. Mycobacterium tuberculosis is the main cause of cervical lymphadenopathy; nontuberculous mycobacteria are relatively common in children and rare in adults.

Objective: To identify and establish the frequency of infectious etiology by nontuberculous mycobacteria in Mexican adult patients with cervical lymphadenopathy.

Methods: The study included 85 patients over 18 years with cervical lymphadenopathy; 45 were HIV-positive, 40 were HIV-negative; they had no history of tuberculosis treatment and were selected from a third-level hospital. It was carried out a biopsy of the lymph node for the histopathological study, a search for acid-fast bacilli, a tube culture to indicate growth of Mycobacterium BACTEC (MGIT-960) and identification of mycobacterial strain by PCR-RFLP (restriction fragment length polymorfism) of hsp65.

Results: In 42 HIV-positive patients (93%), strains corresponded to Mycobacterium tuberculosis complex, two (4.4%) to M. intracellulare and one (2.2%) to M. gordonae. Among HIV-negative patients, 39 of strains (97.5%) corresponded to patients with M. tuberculosis complex and one strain (2.5%) to M. fortuitum.

Conclusion: The presence of nontuberculous mycobacteria was found in 4.7% of all cases. Despite this low frequency, it must be taken into account as a possible cause of lymphadenopathy, since its prompt identification enables introducing specific treatment.