TB Manual

Table 3 shows the sites of childhood TB as reported to the Public Health Agency of Canada (PHAC) for 2018-2020. In Canada, many children with TB disease are asymptomatic at presentation. They are often identified through active case finding as contacts of patients with infectious TB and are found to have abnormal chest x-rays. This is especially true of children under 5 years old.¹⁰

Children may also present with symptoms or signs suggestive of disease.⁵ In high-burden countries, persistent cough, failure to thrive, unexplained prolonged fever or lethargy have all been identified as symptoms of concern. Many clinical diagnostic scoring systems have been developed, but they are not well validated and lack specificity.¹¹ In young infants, clinical features may be nonspecific: weight loss, hepatosplenomegaly, respiratory distress, fever, lymphadenopathy, abdominal distention, lethargy and/or irritability.^12,13 Poorly responding pneumonia at any age should prompt consideration of TB.¹⁴ Clinical case definitions of childhood intrathoracic TB are intended for use in clinical research to evaluate diagnostic assays, and not for individual patient diagnosis or treatment decisions.¹⁵ Older children and adolescents are more likely to present with adult-type disease and often endorse the classic triad of fever, night sweats and weight loss.¹⁶ Those with pulmonary disease are also more likely to present with respiratory symptoms (productive cough and sometimes hemoptysis). Physical findings are often minimal relative to their chest x-ray abnormalities, which include lung infiltrates, typically but not always in the upper zone(s), sometimes with cavities.^17,18 TB disease in adolescents in Canada and other high-income countries is often extra-pulmonary.¹⁰ Presentation may be protean: TB may mimic inflammatory bowel disease, brain or bone tumors, or involve almost any system in the body.¹⁹ Delay in diagnosis of adolescents is common and may reflect a lack of suspicion by clinicians.¹⁹ Failure to send sputa for mycobacterial smear and culture in adolescents with a productive cough and epidemiologic risk factors for TB contributes to this delay.

Any extra-pulmonary site may be involved, most commonly extrathoracic lymph nodes. Mycobacterial cervical lymphadenitis in children is most commonly due to non-tuberculous mycobacteria. However, lymph node disease due to M. tuberculosis should be strongly considered in those with risk factors. TB lymphadenitis is more common in older children and adolescents (Table 3).²⁰ Miliary/disseminated disease and CNS disease, the most life-threatening forms of TB, are more likely to occur in children <2 years old, children who were not identified as contacts and the immunocompromised. In Canada, CNS TB has occurred more often in children ≥5 years old (Table 3), possibly reflecting the influence of contact tracing and contact management.

Epidemiologic risk factors and/or a clinical picture compatible with TB should prompt appropriate testing for TB.

Table 3. Childhood TB by site of disease for the combined years 2018 and 2019.

Switch To: Français