How is TB reactivation?

➢ Due to some environmental (e.g., HIV infection, malnutrition etc.) or genetic factors, the bacteria will reactivate in 10% of the latently infected individuals and provoke the death of the infected macrophages ➢ A necrotic zone (called caseum due to its milky appearance) will develop in the centre of the granuloma ➢ Ultimately the structure will disintegrate allowing exit of the bacteria, which will spread in other parts of the lungs and more lesions will be formed. ➢ Infection will also be transmitted to other individuals due to release of the infected droplets by coughing