Investigations #1

     Tuberculosis (TB) is a disease that is claiming millions of lives each year. It is believed that about one third of the world’s population is infected and it is currently one of the leading causes of death in the world. TB is caused by bacteria called Mycobacterium tuberculosis. People can be infected by the bacteria and not even know that they have the disease. Some of the signs and symptoms include coughing that lasts longer than 3 weeks, productive cough (blood & mucus), weight loss, chest pains, sweating at night, and weakness. In most cases, symptoms do not appear until the victim’s immune system weakens, such as in people with HIV and people of old age.

       

     M. tuberculosis is an airborne disease, where people can be infected when an infected person coughs, sneezes, or talk. The bacteria are ingested by alveolar macrophages but they are able to survive and multiply intracellularly by inhibiting phagolysosome production. Granulomas (tubercle) form from the accumulation of activated macrophages and other mononuclear phagocytes, which surrounds the infected macrophages with the bacilli. Granulomas contain and inhibit the growth of the bacilli. However, when the immune system of an infected person weakens the walls of the granuloma loses structural integrity and ruptures, allowing the bacilli to escape and spread to other organs.

To learn more about the disease visit: http://www.cdc.gov/tb/

References

Nancy A. Knechel. Tuberculosis: Pathophysiology, Clinical Features, and Diagnosis.

      CriticalCareNurse 2009; 29(2). 

Lakshimi PS, Verma D, Yang X, Lloyd B, Daniell H. Low Cost Tuberculosis 

      Vaccine Antigens in Capsules: Expression in Chloroplasts, Bio-Encapsulation, Stability, 

      and Functional Evaluation In Vitro. Plos One 2013; 8(1).