Approaches to detecting TB in children and youth

Question 1

TB must always be considered in:

Answer 1

• Indigenous children & youth who lived or live in areas with RF (overcrowded, poorly ventilated houses)
• foreign-born children from countries with TB

Question 2

What is a Ghon focus and complex?

Answer 2

• Ghon focus: parenchymal site

* Ghon complex: includes adjacent hilar lymphadenopathy

Question 3

What % of kids have primary infection TB ?

What % of kids have reactivation TB?

Answer 3

5-10% have early primary disease

90-95% have LTBI. Of these, 5-10% have reactivation disease (post-primary)

Question 4

When does TB reactivation disease tend to happen?

Answer 4

after 10 yrs old

sometimes precip by immunosuppression or puberty

Question 5

How does disseminated or extra-pulmonary TB present?

Answer 5

• infants at high risk
• constitutional symptoms predominate (wt loss, poor feeding, prolonged/recurrent fever, lethargy, irritability)
• syndromic presentations: pneumonia, meningitis osteoarticular, sepsis unresponsive to antibiotics
  
  • Organs: lung, brain, retina, liver, spleen, bone marrow, muscle
• Pulmonary: miliary nodule common, can have diffuse alveolar pattern or ARDS
• Meningitis: CSF has pleocytosis with lymphocytic predominance
  
  • MRI may be helpful

Question 6

What are RF for reactivation TB disease?

Answer 6

genetics
immunosuppression (HIV, diabetes)
malnutrition
medications (steroids, biologics)

Question 7

How does reactivation TB present?

Answer 7

Pulmonary - May present with “adult-type” cavitary disease or infiltrates in apical and upper lung zones

Extra pulm - lymphadenitis, meningitis, liver/spleen granulomatous disease, osteomyelitis, peritonitis, pleural disease

Disseminated - rarer

Question 8

What do you have to test all TB + patients for?

Answer 8

HIV

Question 9

What is specificity for TST & IGRA?

Answer 9

TST 60%
IGRA 95%

• > =2 yrs: TST and IGRA have similar sn/sp for LTBI (but IGRA more specific)
• <2 yrs: TST possibly more sensitive than IGRA

Question 10

Cut offs for TST induration

Answer 10

• 0-5mm “infants or young children with suspected TB disease may even have 0 mm or <5mm induration”
• > = 5 mm for immunocompromised or contacts of cases
• > = 10 mm for others

Question 11

What % of kids with BCG will have TST >= 10 mm at 10 yrs old?

Answer 11

• if BCG - only 1% will have TST >=10 mm later 10 years of age

Question 12

What causes FN in TST/IGRA?

What causes FP in IGRA?

Answer 12

• Both IGRA and TST have false-negative results in immunosuppression
• IGRA can be false positive from recent TST

Question 13

What is the time cutoff for reporting TB disease to PH?

Answer 13

• TB disease must be reported to public health authorities within 48h of diagnosis

Question 14

What is TB isolation protocol?

Answer 14

• isolate in hospital or home if resp secretions are smear positive until 3 sputum specimens smear negative
  
  • or if initial smears negative: after full 2 wk of DOT

Question 15

What do you do if child/youth is contact of an index TB case?

Answer 15

• CXR and TST
  
  • obtain drug sensitivites of index case
  • children <5 yrs
    
    • initial TST <5mm
      
      • window prophylaxis with one TB drug (identified as effective for treating source)
      • second TST at 8-10 wk after “break of contact” while index case was still infections
      • if second TST <5mm - discontinue window prophylaxis
  • Children >= 5 yrs
    
    • initial TST <5mm
      
      • no window prophylaxis
      • Second TST at 8-10 wk
    • initial TST >5 mm (and CXR normal with no symptoms): Tx for LTBI

Question 16

What is tx for LTBI?

for active TB?

Answer 16

• LTBI: Isoniazid, rif, or rifapentin/isoniazide

* Active TB: 4-drug regimen