Tuberculosis, also known as TB, is a bacterial infection. While tuberculosis primarily affects the lungs, it can also attack other parts of the body, including the kidneys, spine, brain and bones. There are two classifications of tuberculosis: latent and active. Individuals with latent TB are asymptomatic and not contagious. They may, however, be in danger of developing active TB. Those infected with active TB develop symptoms and are in danger of infecting others. The number of reported cases of tuberculosis in the United States has declined annually over the years. Nonetheless, worldwide, TB is a disease to be reckoned with. While there have been fewer than 10,000 cases of tuberculosis reported in this country in 2014, there have been 9 million cases worldwide, more than 10 percent of which resulted in fatalities.
Causes of Tuberculosis
Tuberculosis is caused by an airborne bacterium known as Mycobacterium tuberculosis. The infection is spread when an infected patient sneezes, coughs, talks or laughs. What makes TB different from most other infections is that, in the majority of individuals, the infection may remain dormant for years. Those infected may not suffer symptoms until the disease becomes activated. This will happen if, or when, their patient‘s immune system becomes weakened.
Risks for Tuberculosis
While tuberculosis is contagious, it is not easily transmissible. The disease is rarely spread among strangers, but may be contracted from a patient with active disease in a home or close workplace setting, especially after prolonged exposure. Once patients with TB have been treated for at least 2 weeks, they are no longer contagious. It is, however, possible for patients who contract the disease to develop symptoms within weeks or to take years to become symptomatic.
Patients are at greater risk of contracting tuberculosis if the have compromised immune systems as a result of:
- Advanced age
- Diabetes or other chronic illness
- Chemotherapy treatment
- Alcoholism or drug abuse
- Use of anti-rejection medications
Because TB is considerably more prevalent in countries with more poverty and less sanitation, living in, or traveling to, such countries puts an individual at higher risk of developing the disease.
Symptoms of Tuberculosis
An active tuberculosis infection causes symptoms and becomes contagious two to eight weeks after infection. A cough that lasts longer than 3 weeks is the most common symptom of tuberculosis, but others can include:
- Unintentional weight loss
- Chest pain
- Loss of appetite
- Coughing up blood
- Night sweats
- Shortness of breath
Tuberculosis patients may also experience more far-reaching symptoms because TB does not only affect the respiratory system, but can also affect other parts of the body. Other symptoms vary according to the body part affects. Tuberculosis of the kidneys, for example, may cause blood in the urine, and tuberculosis of the spine may result in back pain.
Diagnosis of Tuberculosis
In order to diagnose TB, the doctor has to perform a thorough physical examination, paying special attention to whether the patient has any enlarged lymph nodes. In addition, if TB is suspected, a series of diagnostic tests are performed, including:
- Tuberculin skin test, called the Mantoux test
- Chest X-ray of CT scan
- Blood test
- Sputum examination
While the Mantoux test for TB can detect the presence of the illness even before symptoms appear, it is not entirely reliable and may provide false positive or false negative responses in a number of situations.
Treatment of Tuberculosis
Tuberculosis is typically treated with antibiotics on a long-term basis, usually for 6 to 12 months. Patients with latent TB may be administered medication to keep their infections from becoming active. Because antibiotics have been used to combat TB for over half a century, some TB germs have become resistant to antibiotics commonly used to treat the disease. New antibiotics have been developed to use on patients for whom the older antibiotics are not working. It is important, since TB has a tendency to reside in the body for long periods, that the patient be checked regularly and that the course of antibiotic treatment be completed.