Tuberculosis, or TB, is a significant cause of illness and death worldwide. According to MayoClinic.com, about 2 million people die from TB each year. According to "Harrison's Principles of Internal Medicine," prior to the advent of modern treatments, about half of TB patients died within five years of diagnosis. TB is caused by the bacteria Mycobacterium tuberculosis. It spreads through the air via droplets released by infected people when they talk or cough.
Pulmonary Tuberculosis
According to "Harrison's Principles of Internal Medicine," the lungs are the primary location of tuberculosis infections. TB can lie dormant for many years after the initial infection. Symptoms of active disease include bloody cough, chest pain upon breathing and systemic symptoms--fever, weight loss, loss of appetite and night sweats. TB causes the formation of caseous granulomas, which are collections of infected material that become necrotic, or experience cell death, in the middle. Granulomas can erode the airway walls, allowing the TB bacilli stored inside access to the open air. When the infected person coughs, the TB bacilli are released into the air and can infect others. Another symptom of TB infection is accumulation of fluid in the lining of the lungs, causing shortness of breath.
Genitourinary TB
TB can affect the kidneys, ureters and bladder. Symptoms include increased urinary frequency, painful urination and blood in the urine. The disease can destroy the kidneys, but can remain asymptomatic until renal failure is evident. TB can affect the fallopian tubes and the lining of the uterus, leading to infertility, pelvic pain and menstrual irregularities.
Skeletal TB
TB can involve the vertebrae and the joints. A joint infection initially causes pain and inflammation. Untreated, it can lead to destruction of the joints. Spinal tuberculosis is known as Pott's disease. Collapse of the vertebrae can lead to kyphosis, meaning that the person becomes hunchbacked. Another complication is paraplegia, which is usually due to an abscess compressing the spinal cord. This is a medical emergency that requires immediate drainage of the abscess.
Nervous System Involvement
According to "Harrison's Principles of Internal medicine," TB of the central nervous system is most common in children and adults infected with HIV. Symptoms of tubercular meningitis include the symptoms of fever, irritability, headaches, confusion and a reduced level of consciousness. Meningitis due to TB develops more slowly than bacterial meningitis. Weakness of the cranial nerves can occur, leading to symptoms such as paralysis of eye movements. Without treatment, tuberculous meningitis is fatal. Even with treatment, long-term neurological complications are common.
References
- Mayo Clinic: Tuberculosis
- "Harrison's Principles of Internal Medicine"; Anthony Fauci, et al.; 2008
