The Epidemiology of Extrapulmonary Non-tuberculous Mycobacterial Infection in a Pediatric Population

Abstract

Background: Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and a well-known cause of lymphadenitis, skin and soft tissue infections. The aim of this study was to evaluate the epidemiology of extrapulmonary pediatric NTM infections occurring from 2000 to 2017 in Queensland, Australia. Methods: All cases of NTM and TB are notifiable under the Queensland Public Health Act (2005) and associated regulations (2005). Data from 2000 to 2017 inclusive was collected from the Notifiable Conditions Database, a laboratory based notification system that covers private and public laboratory systems. Pediatric population demographic data were obtained from the Australian Bureau of Statistics by researching the number of children 0–14 years of age in Queensland from 2000 to 2017; both annual and averaged population was determined. The statistical software SPSS and Tableau was used for analysis. Results: The mean age of diagnosis was 2.5 years with a majority of the cohort being women. Mycobacterium avium was the most commonly diagnosed pathogen. Geographic regions with the highest numbers of cases were predominantly tropical and coastal areas. M. haemophilum emerged as a more common pathogen from 2011 following a period of major flooding. Conclusion: Characteristics of the cohort of children susceptible to NTM disease appears consistent with previous reports. However, changes in the epidemiology of NTM infection (such as incidence, species, and geographic distribution) in children may be linked to environmental and weather factors.

Overview of nontuberculous mycobacterial disease in children

“…Lymphadenitis is the most common NTM clinical syndrome in children, particularly those aged 1–5 years 2,3,5 . Cervical and submandibular lymph nodes are most commonly affected 2 .…”

“…2,3,5 Cervical and submandibular lymph nodes are most commonly affected. 2 Infection usually follows peroral inoculation, although can also involve direct inoculation through the skin and be associated with skin and soft tissue infection. 5 Infection is usually indolent, developing over weeks, involving unilateral lymph nodes that are non-tender, with overlying violaceous skin.…”

“…2 Geographical and seasonal variations in incidence have been demonstrated. 2,3 The key risk factor identified for disseminated NTM disease is innate or acquired immunodeficiency. In recent years, the role of immunological factors in the development of NTM disease, particularly the association between disseminated NTM disease and Mendelian susceptibility to mycobacterial diseases (MSMD), has increased.…”

“…In children, peak incidence occurs between the ages of 1 and 5, and most commonly presents as lymphadenitis 2 . Geographical and seasonal variations in incidence have been demonstrated 2,3 . The key risk factor identified for disseminated NTM disease is innate or acquired immunodeficiency.…”

“…Globally, the incidence of NTM disease appears to be increasing in both children and adults 1 . In children, peak incidence occurs between the ages of 1 and 5, and most commonly presents as lymphadenitis 2 . Geographical and seasonal variations in incidence have been demonstrated 2,3 .…”