Tuberculosis In 2012, ~8,600,000 people developed TB, and 1,300,000 died from the disease TB mortality rates have dropped by 45% since 1990 22 countries account for 80% of all cases Treatment is inexpensive, from a first-world perspective: ~$10/person ~13% of those with TB are HIV positive; Most (~74%) in Africa Men are particularly at risk for the disease Multi-drug resistant TB is an emerging global concern Cause of Tuberculosis Historically, TB was blamed on: ‘Evil air’ – a variation on the miasmatic explanation Contagion spread through the breath An act of God TB is caused by Mycobacterium tuberculosis (identifed by Koch) It is related to the zoonotic infection M. Bovis There is evidence that TB is a very ancient disease; the current variant likely emerged with the domestication of cattle, 4,000-8,000 years ago Tuberculosis TB is a disease of the lungs (it can also affect the spine, kidneys, and brain) It is passed person-to-person via droplet transmission Lungs are damaged by the inflammatory response to infection, causing damage to lung capillaries and progressive loss of alveoli, which impairs lung capacity Two forms: Latent TB Active TB Chills Fever Night sweats Chest pain Coughing (which may involve blood or sputum) Weight loss and loss of appetite Fatigue Risk factors for TB HIV+ Very young or old age Substance abuse Diabetes mellitus Silicosis Smoking Cancer of the head or neck Leukemia or Hodgkin’s disease Severe kidney disease Low body weight Some medical treatments (involving immunosuppressant drugs) Living in poverty Overcrowding Inadequate nutrition Contaminated water Poorly ventilated housing Stress Tuberculosis in History Late 19th century The rich sought out homes or vacations in warm, arid climates 20th century TB sanatoria Vaccine Antibiotics Emerging drug resistance: Inconsistent application of treatment Inappropriate medications for specific strains Inequality based on sexism, racism, lack of health care for poor A popular attitude in West: Poor nations are overpopulated and non-compliant – why bother?