Tuberculosis: the captain of men of death: airborne, contagious disease which infects nearly 9 million people annually 1/second - and kills over 2. 5 million people every year - or 1/ 15 seconds. Nutrition: protein deficiency is dangerous animal proteins. If immune system is depressed, secondary reactivation occurs: bacteria goes into dormant state, as long as immune system remains active, can cause pulmonary tb and infects lymph nodes, abdomen, skeleton. Infections only found among domesticated animals (closer contact with herd, barns / stalls: aid transmission) In 24hrs, infected host can expel 2-4 billion bacilli. Immune system response - only some of those infected will develop active disease. Mycobacterium tuberculosis: non-motile, rod-shaped bacillus, covered in waxy sheath", does not produce any toxin, multiplies slowly (6-12 hrs, can survive outside of human host, can survive desiccation (fomites, 4,000-gene sequence or genome of the tb bacillus.