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Pediatrics. Tuberculosis in children. Zhi-min Chen Dept. Pediatric Pulmonology Email: [email protected]. Etiology: Tubercle bacillus. Oder Actinomycetales Family mycobacteriaceae Genus Mycobacterium(M.) Species M. tuberculosis M. bovis Non-TB M. Characteristics. Acid-fastness - PowerPoint PPT Presentation
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Tuberculosis in children
Zhi-min Chen
Dept. Pediatric Pulmonology
Email: [email protected]
Pediatrics
Etiology: Tubercle bacillus
Oder Actinomycetales
Family mycobacteriaceae
Genus Mycobacterium(M.)
Species M. tuberculosis M. bovis Non-TB M.
Characteristics
Acid-fastness
Slow-growing
Unusual resistance
Multi-Drug Resistance strain(MDR)
Source of infection
Open Pulmonary Tuberculosis (adult)
acid-fast smear of sputum(+)
copious production of thin sputum
severe and forceful cough
extensive upper lobe infiltrate or cavity
Young children with TB rarely infect others
Route of transmission
By respiratory tract:
airbone mucus droplet nuclei
contaminated dustBy alimentary tract
raw milk
contaminated foodBy others: (Placenta,skin)
Transmission rarely occurs by direct contact with an infected discharge or contaminated fomite!
High-risk population
Genetic background:
twin
racial difference
HLA BW35Environmental factors:
socioeconomic status
overcrowding
poor nutrition
inadequate health care
TB infection and TB disease
TB infection:
inhalation of infective droplet nuclei containing
TB
A reactive tuberculin skin test and the absence
of clinical and radiographic manifestations
TB disease:
Signs and symptoms, or radiographic changes
become apparent
Infection, disease or not
Virulence of the TB strain
The size of inoculin
The hypersensitivity of the individual tissues
Nutritional or social status
Immunologic status
Genetic background
Primary Pulmonary Tuberculosis
Pediatrics
Spreading of M.tuberculosis
Initial focus (local infection at the portal of entry)
Draining lymphatic vessles
Regional lymph nodes
Blood
Other tissues of the body
Primary pulmonary tuberculosis
Clinical types Initial focus
Primary complex lymphangitis
Lymphadenitis
Bronchial lymph node tuberculosis
Primary pulmonary tuberculosis
Clinical manifestation
Surprisingly meager(subclinical)
Infants more likely to develop signs and
symptoms
Nonproductive cough and mild dyspnea as the
most common symptoms
Primary pulmonary tuberculosis
Less common symptoms
Systemic complaints
fever, night sweats, failure-to-thrive,
anorexia, etc.
Bronchial irritation or obstruction
localized wheezing
Prognosis
Improve or dissolve
Completely resolution
Induration
Calcification
Local progress
Exacerbation
Tuberculous meningitis
Most common in children of 6mo~4yr
Usually develops during the lymphohematogenous
dissemination of the primary infection
High mortality and high morbidity
Tuberculous meningitis: Clinical manifestation
Stage 1: Prodromal stage
Stage 2: Transitional stage
Stage 3: Terminal stage
Stage 1: Prodromal stage
Lasts 1~2wk
Nonspecific symptoms: character
alteration, fever, headache, malaise,
irritability, drowsiness
Focal neurologic signs absent
Stage 2: Transitional stage
Increased intracranial pressure: headache,
projectile vomiting, papilledema
Meningeal irritation: nuchal rigidity, Kernig’s
sign, Brudzinski’s sign
Toxic appearance: fever, anorexia, nausea
Others: cranial nerve palsies, convulsion
Stage 3: Terminal stage
1~3wk
Exacerbation of neurologic symptoms
Very thin with scaphoid abdomen
Electrolyte imbalance
SIADH
Cerebral salt losing syndrome
Diagnosis
Laboratory study
Clinical diagnosis
Diagnosis
Laboratory study
detection of M. tuberculosis
• Smear acid-fast staining
• Culture (BACTEC, liquid, coloricmetric)
• PCR and Gene probe
Diagnosis
Laboratory study
Isolation of M. tuberculosis
Serology: limited value
• LAM antibody
• 38kDa antibody
• 16kDa antibody
• … …
Diagnosis
Laboratory study
Isolation of M. tuberculosis
Serology
Pathology: biopsy and histology
• Caseous necrosis and encapsulation
Diagnosis
Laboratory study
Others
• INF-γ Releasing Assays( IGRAs)- promising
– INF-γ produced by T-cell responses to
M.tb-special antigens called early secreted
antigenic target 6 (ESAT-6) and culture
filtrate protein10.
– Commercial kits: Quantiferon-TB Gold In-
tube (QFT) and The T-Spot TB (T-Spot) test
Typical CSF picture of tuberculous meningitis, but NOT specific
Pressure
Appearance ground-glass
Cell counts 50~500×106/L, L. predominates
Protein
Glucose <40mg/dl ， or CSF/blood <50%
Chloride
Diagnosis
Laboratory Study
Clinical diagnosis
History
Clinical manifestation
Tuberculin test
Roentgenographic examination
Therapeutic trial
Diagnosis
Laboratory Study
Clinical diagnosis
History: usually need chest film or CT of her parents or family members
Clinical manifestation
Tuberculin test
Roentgenographic examination
Therapeutic trial
Diagnosis
Laboratory Study
Clinical diagnosis
History
Clinical manifestation: Not specific
Tuberculin test
Roentgenographic examination
Therapeutic trial
Diagnosis
Laboratory Study
Clinical diagnosis
History
Clinical manifestation
Tuberculin test: more valuable
Roentgenographic examination
Therapeutic trial
Tuberculin test ： principle & method
Based on delayed type hypersensitivity( type IV)
Two antigen preparations:
Old tuberculin, OT
Protein purified derivative, PPD
Intradermal injection of 0.1ml containing 5
tuberculin units of PPD (Mantoux test)
Tuberculin skin test:
result evaluation
The amount of induration should be measured by a trained person 48~72hours after administration
Intensity:
– or ±: <5mm negative or doubtful
+ : 5~9mm suspicious
++ : 10~19mm positive
+++ : >=20mm strong-positive
++++ : blister,ulcer,lymphangitis,double rings
What does it mean: Positive result
Previous infection with TB
Previous vaccination with BCG
Active tuberculosis
<=3 year without prior vaccination
> = 15mm
conversion occurring within 2 years
What does it mean: Negative result
Not infected with TB
False-negative :
incubation period
immunosuppression or immunodeficiency
technical error or improper reagents
Diagnosis
Laboratory Study
Clinical diagnosis
History
Clinical manifestation
Tuberculin test
Roentgenographic examination
Therapeutic trial
Diagnosis
Laboratory Study
Clinical diagnosis
History
Clinical manifestation
Tuberculin test
Roentgenographic examination
Therapeutic trial
Prevention of TB
Avoiding contact with those with open
pulmonary tuberculosis
BCG (Bacillus Calmette-Guerin)
vaccination
Chemoprophylaxis
Treatment
Antituberculosis therapy:
early, dosage, combination, regular, whole course
intensification stage and consolidate stage
directly observing therapy shortcourse (DOTS)
Corticosteroids
Symptomatic management
Supportive care
