Table 1.
Tuberculosis: Differences between adults and children
| Aspect | Adultsa | Childrena |
|---|---|---|
| Epidemiology | Massive global disease burden that is well quantified; excellent awareness | Massive global disease burden that is poorly quantified; minimal awareness |
| TB control | Main focus of TB control programs | Not recognized as a TB control priority |
| Pathogenesis | Usually “adult-type” lung disease | Usually intrathoracic lymph node disease, but extrapulmonary disease common |
| Infection control | Multibacillary; high infection risk | Paucibacillary; low infection risk, unless cavities or extensive lung involvement; epidemiologic marker of transmission |
| Drug resistance | Difficult to differentiate acquired from primary drug resistance | Nearly always primary drug resistance indicating recent transmission |
| Exposure history | Important, but often neglectedb | Essential part of diagnostic work up |
| Risk of progression to disease | Relatively low risk of progression to disease following TB exposure/infection unless immune-compromised | Highly variable risk of progression to disease following TB exposure/infection—greatest in the very young and/or immune-compromised |
| Preventive therapy | Limited value, except in immune-compromised adults | Definite value in young (<5 yr of age) and/or immune-compromised children |
| Imaging studies | Chest radiographs (CXRs) not routinely required, unless sputum negative for mycobacterial investigations | CXRs (with both anteroposterior and lateral views, of good quality, and competently read) are the most informative study to perform |
| Disease classification | Pulmonary versus extrapulmonary distinction Postprimary TB is a confusing conceptc |
Diverse spectrum of pathology that requires accurate classification |
| Microbiological studies | Relatively easy to collect adequate respiratory specimen and confirm presence of mycobacteria | Difficult to collect adequate respiratory specimens (young children cannot expectorate); smear microscopy has very low yield |
| Treatment (drug-susceptible TB) | With four drugs in intensive phase | With three or four drugs depending on likely organism load and severity of disease in intensive phase |
| Prognosis | Excellent outcomes achievable with timely and appropriate treatment | Excellent outcomes achievable; potentially grave outcome with delayed diagnosis of especially tuberculous meningitis |
Data adapted from supplementary material in Perez-Velez and Marais 2012.
aTypical characteristics in the absence of HIV infection and/or severe immune compromise.
bTaking a careful contact history is often neglected in adults, but it has particular relevance to identify drug-resistant TB suspects.
cThe distinction between primary and postprimary TB obscures the fact that adult-type (postprimary) TB frequently results from recent reinfection and may also occur within months of documented primary infection (particularly in adolescents).