Tuberculosis in Children: Testing, Diagnosis and Treatment for Clinicians

Latent TB infection and TB disease need special handling in children. TB in a child under 15 can be a sign of recent transmission — the younger the child, the more likely — and calls for a quick search for others who may be infected.

Get expert help. State TB programs and the TB Centers of Excellence can advise on latent infection, and clinicians should consult a pediatric TB expert before treating TB disease. For families: TB in children.

Risk

• Exposure: children born in, or who often travel to, countries where TB is common — including some in Asia, Africa and Latin America.
• Progression: infected infants and young children have usually been infected recently and are at high risk of TB disease. Most childhood TB disease is in children under 5 and adolescents over 10, and the youngest are more likely to get life-threatening forms — meningeal and disseminated TB.

Symptoms

Cough; feeling sick or weak, lethargy or less playfulness; weight loss or failure to thrive; fever; night sweats. TB usually affects the lungs but can strike elsewhere — TB meningitis, for instance, can cause sleepiness, headache, irritability and seizures. See clinical signs and symptoms.

Testing

Without symptoms, the only sign of infection is usually a positive TB blood test (interferon gamma release assay) or TB skin test.

• Under 5: CDC guidelines recommend the skin test, though some experts use blood tests; the American Academy of Pediatrics has guidance on blood tests in children.
• Skin test reading depends on the size of the induration (firm swelling) and risk factors. Without other risk factors, 10 mm or more is positive for children under 5 and for children and teens exposed to high-risk adults.
• BCG vaccine can cause a false-positive skin test, and there's no reliable way to tell the difference — so skin tests are read the same way either way. For a child 5 or older who has ever had BCG, recommend the blood test, which BCG doesn't affect.

Medical evaluation

Evaluate every child with a positive test, TB symptoms, or exposure to TB disease: medical history, physical exam, a TB test, chest x-ray, lab tests for TB bacteria (sputum smear, nucleic acid amplification test, culture), and drug-resistance testing if TB disease is found.

• Latent TB infection is diagnosed with a positive test and no evidence of disease — at minimum a physical exam and a normal chest x-ray. Rule out disease before starting treatment.
• TB disease is hard to confirm in children. Young children rarely cough up sputum, so clinicians may use gastric aspiration — a tube through the mouth or nose into the stomach to collect swallowed sputum — usually in hospital, first thing in the morning before the child gets up or eats, with the specimen neutralized or sent to the lab at once. Young children's TB is often paucibacillary (few bacteria), so lab tests are more often negative; TB disease can be diagnosed from symptoms, a positive test, an abnormal x-ray and contact with someone with TB.

Treating latent TB infection

Prefer shorter, more convenient regimens when possible:

• Monitoring: support adherence and watch for side effects. Isoniazid hepatitis is less of a risk in children than in adults; routine liver tests aren't needed without risk factors.
• Directly observed therapy (DOT) — a health worker watching doses taken, in person or virtually — should be considered for high-risk patients such as young children on intermittent regimens or likely to struggle with adherence.
• See the 2020 guidelines for treating latent TB infection from the National Tuberculosis Controllers Association and CDC.

Window prophylaxis

Children under 5 exposed to an adult with TB disease should be treated for latent infection even if the first test is negative and it's been less than 8–10 weeks since exposure. First rule out disease with an x-ray and symptom review. Repeat the same type of test 8–10 weeks after the last exposure: if positive, continue; if negative, treatment can usually stop — provided the child is 6 months or older and the second test was done at least 8 weeks after exposure. Sometimes clinicians choose to give a full course anyway.

Treating TB disease

Choose the regimen based on drug-susceptibility results (from the child or the presumed source), other medical conditions and drug interactions, adjusting for age and weight. For drug-susceptible TB:

Non-severe TB means peripheral lymph node TB, intrathoracic lymph node TB without airway obstruction, uncomplicated TB pleural effusion, or paucibacillary, non-cavitary disease confined to one lung lobe without a miliary pattern.

• Children usually have TB in the middle and lower lung, but in infants it's much more likely to spread — so start treatment as soon as TB is suspected.
• 2HRZ(E)/4HR treats most extrapulmonary TB in children, except disseminated TB and TB meningitis, which need 9–12 months (consult an expert for meningitis).
• All children and teens with TB disease should be treated with DOT, and must take every dose exactly as prescribed.

More: clinical testing and diagnosis · clinical treatment.

Sources

Based on "Tuberculosis Clinical Care for Children," Centers for Disease Control and Prevention; a work of the United States government in the public domain.