Mycobacterium tuberculosis infection in immunocompetent children.

Objective. The purpose of this paper is to present our experience with Mycobacterium tuberculosis infections in immunocompetent children.Subjects and methods. Radiology, pathology, microbiology, and discharge records at two institutions identified the study population. Children who were immunocompromised and those with a positive skin test and no radiological or clinical evidence of active infection were excluded. Active mycobacterial infection was defined by a positive culture, biopsy, or a reactive purified protein-derivative skin test (PPD) with an appropriate clinical presentation and response to therapy and/or known exposure to an adult with active tuberculosis. Results. There were 22 children in whom Mycobacterium tuberculosis (MTb) was identified. Fourteen of the patients with MTb were 5 years of age or younger. The most common sites of radiological involvement were the lungs (15 cases) and the hila (eight cases). Four patients had evidence of extrathoracic MTb infection. Three cases of miliary tuberculosis were identified, all in children less than 9 months of age. Conclusion. Although pulmonary and/or hilar disease remains the most common radiological presentation of childhood tuberculosis, the radiologist must be aware of the many radiological presentations of childhood Mycobacterium tuberculosis infection, and should have a high index of suspicion with the increasing incidence in both normal and immunocompromised children.