Disseminated Nontuberculous Mycobacterial Infection in Patients Who Are Not Infected with HIV in Thailand

Background: Disseminated nontuberculous mycobacterial (NTM) infection is an emerging infectious disease worldwide that occurs mostly in immunocompromised hosts. Disseminated NTM infection is uncommon in persons who are not infected with human immunodeficiency virus (HIV). Recently, we described a group of non-HIV-infected Thai patients whose disease manifestation was a previously unrecognized clinical entity characterized by chronic bilateral lymphadenopathy due to rapidly growing mycobacteria. Most of the patients had coinfection with other opportunistic pathogens and reactive skin diseases. Therefore, in recognition of the increasing significance of this unique disease due to NTM in our country, we initiated a study to assess the prevalence, clinical characteristics, and geographic variations of this disease.

Methods: There were 129 cases of disseminated NTM infection identified from 4 university hospitals located in major areas throughout Thailand. All patients but 1 were adults. Only 12% of patients had underlying diseases. The majority of the patients (81%) lived in the northeast of Thailand.

Results: The most common organ involved was the lymph node (89%), followed by skin and soft tissue (26%), lung (19%), and others. Fifty-nine patients (46%) had 81 episodes of coinfection with other opportunistic infections (e.g., salmonellosis, 32 cases; cryptococcosis, 8 cases; penicilliosis, 8 cases; histoplasmosis, 5 cases). Seventy-seven patients had 86 episodes of reactive skin diseases (e.g., Sweet syndrome, 60 cases; pustular psoriasis, 6 cases; erythematous pustulosis, 5 cases).

Conclusions: These findings suggest a cell-mediated immune defect in these patients that needs to be further investigated. This study strongly suggests that the prevalence of NTM infection in Thailand is increasing. To our knowledge, this is the largest study of disseminated NTM infection among non-HIV-infected patients.