Week 5: Tuberculosis

This week in lecture we discussed Mycobacteria. Mycobacteria is separated into two groups – M. tuberculosis complex and Nontuberculous Mycobacteria (NTMs).  In this post I’ll focus on the first group.  Diseases associated with M. TB complex include asymptomatic to acutely symptomatic, pulmonary to extra-pulmonary, and miliary tuberculosis in which the disease is present in sites other than the lungs such as the spleen, liver, bone marrow, kidney, and eyes.  M. TB complex is transmitted person to person through inhalation of droplet nuelcei (sneezing, talking), aerosols due to contact with wounds, or ingestion.  Common symptoms include prolonged cough, chest pain, fever, chills, night sweats, and weight loss. 

According to the CDC, Tuberculosis is one of the world’s most deadliest disease.  One third of the world’s population is infected and each year, over 9 million people around the world become sick with TB.  Each year there are almost 2 million TB-related deaths worldwide. 

In the United States reported TB cases has been on the decline. 

According to the CDC over 70% of the 6,854 foreign-born TB cases reported in the United States in 2009 were persons born in only 12 countries.  Below is a chart showing the distribution of the reports.

Below you can see that the number of foreign born cases now exceeds the number of US born.

For those avid travelers, in order to prevent exposure to TB, you should avoid close contact or prolonged time with known TB patients in crowded, enclosed environments such as clinics, hospitals, or homeless shelters.  If you know you will be in a setting where TB patients are likely to be encountered you should consult infection control experts.  Procedures for preventing exposure to TB should be implemented.