Table 5.

Summary of differences in tuberculosis between adults and children.

Category	Adults	Children
Transmission	are frequently contagious because they often have: - cavitary lesions - multibacillary disease - pulmonary tuberculosis - less circumscribed social networks - more forceful cough - productive cough	are infrequently contagious because they often have: - non-cavitary lesions - paucibacillary disease - extrapulmonary tuberculosis - more circumscribed social networks - less forceful cough - non-productive cough
Natural history	- risk of progression is 5-10% - time between primary infection and disease is often long (some years)	- risk of progression is: 45% in infants < 1 year of age; 24% in children 1-5 years of age; 15% in adolescents - time between primary infection and disease is often short (1-6 months)
Clinical presentation	- primary infection is often asymptomatic but symptoms and signs are specific - principally develop pulmonary TB	- primary infection is asymptomatic but it may rapidly progress to symptomatic TB disease with not specific symptoms and signs - often develop extrapulmonaryand military TB
Diagnosis	- for screening purposes TST or IGRAs are recommended - detection of M. tuberculosis in sputum smear is achieved in 80% of cases - chest radiography shows cavitary formations	- in children < 5 years of age only TST is recommended because IGRAs may be unreliable - in children ˃ 5 years of age and adolescents TST or IGRAs are recommended - detection in gastric aspirates of M. tuberculosis is achieved in less than 40% of cases - chest radiography shows unspecific lesions (e.g. hilar or mediastinal lymphadenopathy, bronchopneumonia and pleural fluid collections) or may be normal
Treatment	- treatment for latent TB in close contacts should be unnecessary - toxicity induced by anti-tubercular drugs is most common - use of second-line anti-tubercular agents is formally approved - fixed dose drug combinations are available	- treatment for latent TB is always necessary and in close contacts< 5 years it should be started also if TST is negative - toxicity induced by anti-tubercular drugs is less common (also ethambutol is considered safe in young children) - use of second-line anti-tubercular agents is not formally approved - few fixed dose drug combinations are available

TB= tuberculosis; TST= Tuberculin Skin Test; IGRAs = Interferon-gamma Release Assays.