Despite advances in treatments available, tuberculosis (TB) still remains a global pandemic. One third the human population is currently infected with tuberculosis. What is tuberculosis?



The disease tuberculosis is caused by the bacteria Mycobacterium tuberculosis. Tuberculosis can affect any part of the body but usually infects the lungs. Tuberculosis is spread through airborne droplets occurring when an infected individual sneezes, talks, or coughs. However, prolonged exposure to the infected individual must occur before you may become infected. The body may harbor the bacteria while the immune system prevents sickness. For this reason, there are two forms of TB: latent tuberculosis and active tuberculosis.

With latent tuberculosis, the immune system is able to prevent the bacteria from growing. The tuberculosis bacteria remain alive within the body but are inactive at this time. However, the bacteria can become active later in life. Those with latent tuberculosis have no symptoms, do not feel sick, are not contagious, and may develop TB later in life if they do not receive treatment.

Active tuberculosis simply means that the tuberculosis bacteria are growing within the body causing an active infection. Signs and symptoms of active tuberculosis include fatigue, slight fever, chills, night sweats, loss of appetite, unintended weight loss, a cough that lasts three or more weeks producing discolored or bloody sputum, and pain with coughing or breathing. Active tuberculosis is highly contagious.

What is causing the tuberculosis pandemic? Improved public health programs have helped to create a steady decline of tuberculosis cases in the United States. However, the problem is far from solved. Factors that contribute to the spread of tuberculosis in the U.S. and elsewhere include the increase in number of foreign born nationals, crowded living conditions, increase in drug resistant strains of tuberculosis, lack of access to medical care, and the increase in poverty.

Poorly ventilated and crowded conditions help to spread TB. This is one reason tuberculosis cases have reached epidemic proportions. Although the incidence of TB cases in the U.S. is declining, the incidence in other parts of the world is increasing. Half of the reported cases in the U.S. (in 2000) occurred in individuals that were born outside of the U.S. Individuals that live in poverty, move or migrate often usually do not finish the tuberculosis treatment. This is leading to drug resistant forms of tuberculosis.

Drug resistant strains of tuberculosis are a serious problem. Tuberculosis bacteria have developed strains of the bacteria that are resistant to each of the major tuberculosis medications. There are also strains of tuberculosis that are resistant to at least two tuberculosis medications. This multidrug-resistant TB (MDR-TB) is posing an even deadlier threat to those affected. Individuals affected with MDR-TB are much more difficult to treat requiring a long term therapy of up to two years. The medications required to treat these strains can cause serious side effects. This is one great reason to complete the entire course of medication as prescribed by your doctor.

Certain factors increase your risk of contracting tuberculosis. An individual in an immunocompromised state is at risk of developing TB. A number of factors can cause the immune system to be in a weakened state. Some diseases can suppress the immunity such as diabetes, HIV/AIDS, and silicosis. Certain medications can affect the body's immune system which includes chemotherapy drugs and corticosteroids. An increased risk of reactivated tuberculosis has been associated with the use of arthritis medications Enbrel and Remicade.

Individuals within close proximity of those infected with tuberculosis are at an increased risk of developing disease. Individuals in areas of high rates of tuberculosis (Asia, Africa, Latin America, former Soviet Union) have an increased risk of developing tuberculosis. Certain races (Hispanics, American Indians, Asian Americans, African Americans) in the U.S. are at risk of developing tuberculosis. What other factors may increase your risk of developing tuberculosis?

The older adult is at an increased risk of developing tuberculosis due to a weakened immune system. Individuals who are malnourished, lack adequate medical care, or who suffer from long term drug or alcohol abuse are at increased risk of developing tuberculosis. Health care workers are at increased risk of developing tuberculosis also.

If you develop any of the signs or symptoms listed above, you should seek medical advice. Individuals with HIV should be tested for tuberculosis, since the leading cause of death in the AIDS patient is tuberculosis. HIV and tuberculosis have a deadly symbiosis, in which TB increases the rate at which the AIDS virus replicates and HIV reactivates inactive TB. Health care workers are usually tested at least yearly for tuberculosis by Mantoux test. Individuals with latent tuberculosis reveal a positive Mantoux even though no symptoms of the disease are evident. Tuberculosis is also tested by chest x-ray and culture tests (urine, sputum).

Tuberculosis is a preventable disease. There are a few measures one can take to protect their health. First, you should be tested regularly. If you have an immune suppressing disease, live or work in a prison or nursing home, were born in a TB prevalent country, or have other risk factors, then a Mantoux test should be done every six months.

If you test positive without symptoms, speak with your doctor about treatments to reduce the risk of developing active tuberculosis. The most important step you can do for the public and yourself is to finish the entire course of medication. Treatment that is stopped to early allows the bacteria a chance to mutate to a drug resistant form.