A 25 -year-old man from the third world country presents to his doctor with a persistent cough for 3 weeks, low grade fever, and night sweats. His chest x-ray is shown above. The X ray shows mediastinal and right hilar lymphadenopathy and right upper lobe consolidation concerning
for primary tuberculosis (shown by arrows).
The patient's sputum is sent for acid-fast bacillus (AFB) stain and cultures, and the results show acid-fast bacilli consistent with Mycobacterium species.
While culture results are pending, the patient is started on 4 antituberculosis drugs. Fortunately, the sputum culture result shows pan susceptible Mycobacterium tuberculosis, and his treatment is continued.
Introduction: Tuberculosis (TB) is a bacterial infection caused by Mycobacterium . tuberculosis, an
obligate intracellular pathogen that is aerobic, acid fast, and non encapsulated.
TB primarily involves the lungs, although other organs are involved in one-third of cases.
More than 8 million cases occur annually around the world, with nearly 2 million TB-related deaths. 95% of TB deaths occur in low- and middle-income countries.
Risk Factors: Risk factors for infection or progression to active TB include:
• Populations who are at risk to overcrowding and malnutrition.
• Immunocompromised states (e.g., cancer, treatment with tumor necrosis factor antagonists)
• Chronic diseases such as diabetes mellitus or chronic renal failure/hemodialysis
• Genetic susceptibility.
• Injection drug users
• Personnel who work or live in high-risk settings (e.g., prisons, long-term care facilities, and hospitals).
• Adult women (ratio 2:1 adult man).
• Older age (both infection and progression).
• Children younger than 4 years of age who are exposed to high-risk individuals.
• Recent infection
- The disease may be asymptomatic in some patients.
- TB can affect any organ system.