Classic and New Diagnostic Approaches to Childhood Tuberculosis

Table 1

Clinical similarities and differences between adult and childhood TB with relevancy to successful diagnosis.

Feature	Adults	Children
Typical signs	Radiological features and a positive sputum smear	TB can mimic many common childhood diseases. The clinical symptoms in older children are cough, fever, wheezing, fatigue, and failure to gain weight, and in pediatric children are pulmonary parenchymal disease and intrathoracic adenopathy, lymphadenopathy, and central nervous system involvement
X-rays findings	Classical cavitation in lungs	Enlargement of hilar, mediastinal, or subcarinal lymph nodes and lung parenchymal changes, hilar lymphadenopathy with or without a focal parenchymal lesion
TST	Cross-reaction with BCG vaccination and exposition with other mycobacteria
Sampling	Easy sputum and blood sampling	Difficulty to expectorate, blood sampling usually painful in pediatric children
Bacillary load	High bacillary load, easy to find the bacillus when technician is skillful	Lower bacillary load and is usually smear negative even with fluorescent dyes
Bacillus growth in culture	High yields of 90–100%	Confirmation by culture rarely exceeds 30–40%
Tropism of M. tuberculosis	Commonly localized infection in the lungs	Commonly extrapulmonary, disseminated