TUBERCULOSIS: Tuberculosis is a bacterial disease usually affecting the lungs (pulmonary TB). Other parts of the body can also be affected, for example lymph nodes, kidneys, bones, joints, etc. (extra pulmonary TB). Approximately 1,300 cases are reported each year in New York State. Tuberculosis can affect anyone of any age. People with weakened immune systems are at increased risk. Tuberculosis is spread through the air when a person with untreated pulmonary TB coughs or sneezes. Prolonged exposure to a person with untreated TB usually is necessary for infection to occur. It is one of the most serious specific communicable disease in the world. There are three types of bacteria responsible for the disease.
1. Mycobacterium tuberculosis (human type)
2. Mycobacterium bios: endemic in cattles but now also really responsible for the disease in men.
3. A typical or opportunistic Mycobacterium.
PREDISPOSING FACTORS: The bacteria enters into the body through the alimentary tract, gastro intestinal track or respiratory tract. This first entry may not be followed by clinical illness because it depends on some predisposing factors. Those of most practical importance are these.
Age: Mostly people above the age of 45 are affected.
Sex: Mostly males are its victim.
Natural resistance: Varies from man to man and even from region to region.
Standard of Living: Poor housing with crowded living increases the risk of the occupants to suffer from the disease.
Condition affecting individual: Poorly treated diabetes mellitius, gastronomy and silicosis are all predisposed towards T.B. development.
HOW IT AFFECTS THE BODY:
Primary infection: The initial infection usually occurs in the lungs, “The Primary infection,” but it may occur occasionally in the tonsils or in the alimentary tract (GUT) especially the ileocaecal region.
These primary infections are almost invariably accompanied by a caseous lesion (matted together) of the lymph node of that particular affected primary area. For example if the primary focus is in lungs then the lymph nodes of chest are involved, if it is tonsils then lymph nodes in the side of neck are involved producing painless abscess. Similarly in the case bowels, mesenteric lymph nodes are involved.
Fate: Mostly this primary infection ends in healing and calcification. (Deposition of calcium which appears as a white spot in X-ray film).
Sometime this healing, especially in lymph nodes, is incomplete and some bacteria survive.
Circumstance: (Such as poor health due to any other cause) the bacteria is discharged into the blood stream and produces “Haematogenous lesion” such as in kidneys, lungs, bone and joints.
Secondary infection: It may occur after a month or even after several years.
Improper primary treatment or inability to cure the disease.
In some cases, this primary infection fails to heal, especially in adolescene or early adult life and the disease leads to “Progressive pulmonary tuberculosis”
Rarely may this primary focus or associated lymph node rupture into a vein resulting in acute dissemination of disease through the body. That state is called “Milliary Tuberculosis”. This often leads to “T.B. Meningitis”. This progressive pulmonary tuberculosis sometime, result purely as re-infection from an outside source, after the primary focus has healed completely. It affects the delicate covering of the brain and causes, irreversible damage.
If this primary infection undergoes a progressive course. Symptoms and signs may appear after a latent period of weeks or months.
Sign & Symptoms:
History of cough for more than 3 weeks with or without sputum.
Evening fever may be associated.
Loss of weight.
Loss of appetite.
Shortness of breath.
Haemoptysis: Blood in sputum.
History of contact with a T.B. patient.