Tuberculosis

Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis. It most commonly affects the lungs (pulmonary TB) but can affect almost any organ — including lymph nodes, kidneys, spine, and brain. TB spreads through the air when an infected person coughs, sneezes, or speaks, releasing microscopic droplets. Nigeria has one of the highest TB burdens in the world, ranking sixth globally. TB is curable with a full course of antibiotics, but treatment requires taking multiple drugs for a minimum of 6 months. Drug-resistant TB — caused by incomplete or incorrect treatment — is a growing and serious threat.

Pulmonary TB (lung TB) develops gradually: • Persistent cough lasting more than 2–3 weeks: often producing phlegm • Coughing up blood or blood-streaked sputum (haemoptysis) • Chest pain • Unintentional weight loss • Night sweats • Low-grade fever, particularly in the evenings • Fatigue and weakness • Loss of appetite Extrapulmonary TB varies by organ: • TB lymphadenitis: swollen, painless lymph nodes (especially in the neck) • Spinal TB (Pott's disease): back pain and potential paralysis • TB meningitis: severe headache, stiff neck, confusion • Miliary TB: widespread dissemination causing fever, weight loss, multi-organ involvement

TB is caused by Mycobacterium tuberculosis, spread through the air when an infected person coughs, sneezes, or speaks. TB is NOT spread by sharing food, water, or touching an infected person. Two forms of infection: • Latent TB infection: bacteria are present but contained by the immune system. The person has no symptoms and is not infectious. About 10% will develop active disease in their lifetime. • Active TB disease: the immune system fails to contain the bacteria, which multiply and cause symptoms. Other causes of TB spread: prolonged exposure in enclosed spaces with poor ventilation, particularly overcrowded homes or prisons.

• Close contact with someone with active pulmonary TB • HIV infection: the single most important risk factor; HIV weakens the immune system's ability to contain TB • Malnutrition and underweight • Diabetes mellitus • Smoking and heavy alcohol use • Silicosis (dust exposure: miners, quarry workers) • Overcrowded living or working conditions • Immunosuppressive medications (corticosteroids, chemotherapy) • Very young children and elderly individuals • Previous inadequately treated TB

• Drug-resistant TB (MDR-TB): caused by incomplete treatment; requires longer, more toxic, and more expensive regimens • Respiratory failure from extensive lung damage • Massive haemoptysis (life-threatening blood loss) • Pleural effusion (fluid around the lungs) • TB meningitis: permanent neurological damage, hearing loss, or death • Spinal damage and paralysis (Pott's disease) • Pericarditis (inflammation of the heart sac) • Kidney failure from renal TB • Infertility from genital TB • Death: untreated TB has an approximately 50% case fatality rate

BCG vaccination: • Given to all newborns in Nigeria; protects against severe childhood TB (meningitis, miliary TB) but not reliably against adult pulmonary TB HIV prevention and treatment: • HIV-positive individuals should receive TB preventive therapy (isoniazid) and be closely monitored • Early ART reduces TB risk Infection control: • Cover mouth and nose when coughing; ensure adequate ventilation • Patients are no longer infectious after approximately 2 weeks of effective treatment Treatment adherence: • Completing the full 6-month course exactly as prescribed prevents drug resistance • Free TB treatment is available through Nigeria's DOTS programme at government facilities