Tuberculosis
Tuberculosis or TB is a serious infectious disease as a result of mycobacterial bacteria that primarily affect the lungs. Tuberculosis often affects the lungs as well as the central nervous system , the circulatory system, the genitourinary system and the lymphatic system.  Other body areas, such as the GI system, joints, bones, and the skin are involved. 
When one has tuberculosis, they have a chronic cough, often with blood-tinged sputum, low grade fever, sweats at night and loss of weight.  The diagnosis is often made by chest XRAY, sputum analysis or a TB skin test.  Microbiological cultures of other bodily fluids can show the Mycobacterium. 
Tuberculosis is an airborne disease and spreads when people who suffer from the disease cough, spit or sneeze on another person.  A third of the population of the world would show an infection with tuberculosis and every second, another person is afflicted.  Most of the cases of tuberculosis, however, are not symptomatic and the infection is latent.  About one in ten of the latent infections finally progress to being an active disease state that, if left without treatment, will kill over half of its sufferers.  The statistics from 2004 show that there are 14.6 million cases of chronic disease, almost 9 million new cases of the disease and 1.6 million deaths from the disease, mostly in undeveloped countries. 
There are increasing cases of tuberculosis in developed countries due to compromise of the immune system from immunosuppressive drugs, drug use or AIDS.  There is an increase in cases of tuberculosis that are unresponsive to the usual antibiotics.  About 80% of the population of most African and Asian countries are positive for tuberculosis. 
Symptoms
Most TB is considered pulmonary TB and the symptoms are related to the lungs.  Sufferers cough up blood, have chest pain, a productive cough filled with Mycobacterium and systemic symptoms.  The systemic symptoms include loss of weight, night sweats, fever, chills, pale skin and overall fatigue.
In a quarter of cases, the disease moves from the lungs to other body areas.  This is more likely in patients who are immunosuppressed and in children.  The sites affected other than the lungs include the pleura or lining of the lungs, the nervous system (meningitis), in the lymphatic system or in the urinary tract system.  The most serious form of TB is known as disseminated TB, also called miliary TB.  While miliary TB is not considered contagious, it may occur at the same time as pulmonary TB, which is considered contagious.  
Evolution
Tuberculosis evolved along with humans for a great many thousands of years and perhaps as long as several million years ago.  The oldest human remains believed to be infected with TB are about 9000 years of age.  Genetic differences in different strains of mycobacterium help researchers understand patterns of contagion of the disease.
Disease Transmission
As mentioned the disease is airborne and is transmitted through coughing, spitting, or speaking near someone who is susceptible to the disease.  The inhalation of a single Mycobacterium can result in a new disease occurring.  One needs prolonged, intense or frequent contact with a contagious person in order to have a high risk of getting the disease.  In high risk cases, the infection rate is 22%.  One can get TB by sharing needles with someone else and being an employee of a high risk medical facility.  Children are at higher risk of getting the disease. Each actively affected individual infects 10-15 people per year. Fortunately after a couple of weeks of therapy, a non-resistant, active tuberculosis individual becomes non-contagious.   
Doctors use antibiotics to treat tuberculosis.  The two most common antibiotics are rifampin and isoniazid.  The treatment of TB requires long periods of treatment (from 6-12 months).  This form of treatment eliminates Mycobacteria from the body.  Active TB is best treated with several types of antibiotics.  Those with latent disease are treated with a single antibiotic to prevent the person from eventually going on to redevelop active disease.  
There have been found reductions in glutathione levels in tuberculosis and an increase in oxidation.  This has the potential to cause oxidation damage to the red blood cell membranes.  Mycobacterium tuberculosis is sensitive to glutathione.  There appears to be an important role of glutathione in the control of macrophages in cases of Mycobacterium tuberculosis.