Tuberculosis%20-%20pulmonary%20(pediatric) Signs and Symptoms
Introduction
- The number of tubercle bacilli expelled in the air by a tuberculosis (TB) infected person is directly related to their infectiousness
- TB transmission is rare in children <10 years old due to their inability to expectorate sputum and low TB bacilli load in their sputum
Etiology
- Caused by Mycobacterium tuberculosis, a Gram-positive bacteria with slow growth rate that is enhanced by 6-8% CO2 and temperature of 35-40°C
Pathophysiology
- Primarily transmitted through airborne route
- Other uncommon modes of transmission: Ingestion of contaminated, unpasteurized dairy products from infected cattle (M bovis) or through skin inoculation
Risk Factors
- Tuberculosis (TB) infection in children is usually obtained from an infectious adolescent or adult depending on the closeness and length of their contact, and the index case’s severity of lung involvement and infectiousness
- Children <5 years old have increased susceptibility to TB infection
- Presence of human immunodeficiency virus (HIV) infection and malnutrition increases the risk for TB
- Requires at least 5-200 bacilli to cause an infection
- Usually takes 3 weeks to 3 months for an inhaled tubercle bacilli to cause a reactive tuberculin skin test