Week 6: Mycobacteria

Hello everyone, this week in our Infectious Disease lecture we discussed Mycobacteria.  We spent a great deal of time discussing Mycobacterium tuberculosis, the etiological agent responsible for most case of tuberculosis in humans.  In the United States 4,495 cases of tuberculosis were documented in 2009, 126 of which were in Alabama.  According to the World Health Organization, there are 8.4 million new cases of tuberculosis each year worldwide.  Tuberculosis tends to be most prevalent among immigrants, drug or alcohol abusers, the homeless, and the immunocompromised, particularly those infected with HIV.  Risk factors associated with tuberculosis infection include crowded living conditions, health status of the individual, behavioral risks, environmental and social factors, poverty level, and the fact that the organism is found everywhere.  M. tuberculosis is transmitted primarily through inhalation of droplet nuclei expelled through talking, sneezing, and singing, although it may also be contracted via aerosols due to contact with wounds and tissue of an infected individual.  The spectrum of the diseases associated with M. tuberculosis range from asymptomatic to the typical pulmonary condition, to military tuberculosis in which the disease presents in areas other than the lungs including the spleen, liver, bone marrow and kidneys, to name a few.  Symptoms of typical pulmonary tuberculosis include a productive, prolonged cough, chest pain, and hemoptysis.  Systemic symptoms include fever, chill, night sweats, appetite loss, weight loss, and easy fatigability.

The following is an interesting article I found regarding tuberculosis in ancient Egypt.  Scientists have been able to utilize molecular techniques in order to identify M. tuberculosis in mummies.  Hope you enjoy it!

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(05)65185-9/fulltext