Mycobacterium Tuberculosis Infection

Mycobacterium tuberculosis is an acid fast, gram-positive bacterium that can survive for long periods of time in the air and in sputum. It causes tuberculosis (TB) when it infects a person. The bacterium can affect any tissue in the body but attacks the lungs more often. Tuberculosis is spread in the air from person to person when a person with active tuberculosis lung infection coughs, talks, sings or sneezes into the air.

Types of Tuberculosis

• There are two types of mycobacterium tuberculosis infection and they are the latent tuberculosis infection and the active tuberculosis disease. A person with the latent tuberculosis infection will not feel sick and will not show any symptoms of TB because his body's immune system symptoms fights it off effectively. This person cannot transmit the bacteria to other people but will test positive for tuberculosis and have a normal chest x-ray. He can however develop active tuberculosis if his immune system is depressed because the bacteria is still in his body. The person infected with the active TB disease will feel sick and will show signs and symptoms of tuberculosis and can transmit the infection to other people. He will test positive for tuberculosis and have an abnormal chest x-ray.

Risk factors

• People who are at risk for getting tuberculosis are people who are in close contact with a person that has active tuberculosis and people born in Russia, Africa, Asia, Eastern Europe and Latin America where there are high rates of TB. Residents of crowded places like homeless shelters, long term care facilities and correctional facilities are at risk for TB as well as health care workers who are exposed to persons with active tuberculosis. Children exposed to adults who are at risk for getting TB and people whose immune systems are weak are also at risk for getting tuberculosis.

Signs and Symptoms

• The most common type of mycobacterium tuberculosis infection is pulmonary tuberculosis which is also called lung tuberculosis. The signs of lung tuberculosis are a bad cough that lasts 3 weeks or longer, pain in the chest, night sweats, coughing up blood or sputum, night sweats, fever, chills, weight loss and loss of appetite.

Testing and Diagnosis

• To test for tuberculosis, x-rays, sputum, skin or blood can be used. A sputum smear helps in detecting the acid fast bacteria. A sputum culture can also be done to confirm a diagnosis of tuberculosis. Chest x-rays are used to determine the presence and extent of the disease. The skin test involves injecting some fluid called the tuberculin into your skin and the results of the skin test are read withing 48 to 72 hours. Blood tests for TB are new and are used to measure the body's immune response to TB.

Treatment

• Latent tuberculosis infection is treated with the drug Isoniazide (INH) for nine months. It kills off the bacteria in a person with latent tuberculosis infection so that they don't develop active tuberculosis disease at a later date. Treatment for active tuberculosis disease lasts 12 months and involves a combination of different drugs. It is important for the person being treated for tuberculosis to take all of his medication as prescribed so that the TB infection is cured. If he stops taking his medication at anytime or doesn't take his medication for the entire time it was prescribed, the bacteria may become resistant to the drug and get more difficult to kill.

Vaccines

• The Bacille Calmette-Guérin vaccine also known as BCG is a vaccine for tuberculosis. It is not often used in the United States but is given to newborns and children in other countries where TB normally occurs.

Prevention/Solution

• If you have TB, you can reduce the risk of spreading it. Cover your mouth and nose when you cough or sneeze with double ply tissue. Dispose of the tissue right away into a closed plastic bag. Wash your hands after coughing or sneezing and avoid areas that are crowded and poorly ventilated.