Jan 17, †Ј What Is Tuberculosis? Tuberculosis (TB) is a contagious infection that usually attacks your lungs. It can also spread to other parts of your body, like your brain and spine. A type of bacteria. TB disease in the lungs may cause symptoms such as a bad cough that lasts 3 weeks or longer pain in the chest coughing up blood or sputum (phlegm from deep inside the lungs).
Tuberculosis TBinfectious disease that is caused by the tubercle bacillusMycobacterium tuberculosis. In most forms of the disease, the bacillus spreads slowly and widely in the lungscausing the formation of hard nodules tubercles or large cheeselike masses that break down the respiratory tissues and form cavities in the lungs. Blood vessels also can be eroded by the advancing disease, causing the infected person to cough up bright red blood.
During the 18th and 19th centuries, tuberculosis reached near-epidemic proportions in the rapidly urbanizing and industrializing societies of Europe and North America. Since the s, antibiotic drugs have reduced the span of treatment to months instead of years, and drug therapy has done away with the old TB sanatoriums where patients at one time were nursed for years while the defensive properties of their bodies dealt with the disease.
Today, in less-developed countries where population is dense and hygienic standards poor, tuberculosis remains a major fatal disease. In addition, the successful elimination of tuberculosis as a major threat to public health in the world has been complicated by the rise of new strains of the tubercle bacillus that are resistant to conventional antibiotics.
Infections with these strains are often difficult to treat and require the use of combination drug therapies, sometimes involving the use of five different agents. The tubercle bacillus is a small, rod-shaped bacterium that is extremely hardy; it can survive for months in a state of dryness and can also resist the action of mild disinfectants.
Infection spreads primarily by the respiratory route directly from an infected person who discharges live bacilli into the air. Minute droplets ejected by sneezing, coughing, and even talking can contain hundreds of tubercle bacilli that may be inhaled by a healthy person. There the bacilli become trapped in the tissues of the body, are surrounded by immune cells, and finally are sealed up in hard, nodular tubercles. A tubercle usually consists of a centre of dead cells and tissues, cheeselike caseous in appearance, in which can be found many bacilli.
This centre is surrounded by radially arranged phagocytic scavenger cells and a periphery containing connective tissue cells. Individual tubercles are microscopic in size, but most of the visible manifestations of tuberculosis, from barely what is considered a felony in pa nodules to large tuberculous masses, are conglomerations of tubercles.
In otherwise healthy children and adults, the primary infection often heals without causing symptoms. The bacilli are quickly sequestered in the tissues, and the infected person acquires a lifelong immunity to the disease.
A skin test taken at any later time may reveal the earlier infection and gy immunity, and a small scar in the tuberculowis may what do you mean by tuberculosis visible by X-ray.
Tuberuclosis this condition, sometimes called latent tuberculosis, the affected person is not contagious. In some cases, however, sometimes mran periods of time that can reach 40 years or more, the original tubercles break down, releasing viable bacilli into the bloodstream. From the blood the bacilli create new tissue infections elsewhere in the body, most commonly in the upper portion of one or both lungs. This causes a condition ylu as pulmonary tuberculosisa highly infectious stage of the disease.
In what does rated mean in movies cases the infection may break into the pleural space between the lung and the chest wall, causing a pleural effusionor collection of fluid outside the lung.
Particularly among infants, the elderly, and immunocompromised adults organ transplant recipients or AIDS patients, for examplethe primary infection may spread through the body, causing miliary tuberculosisa highly fatal form if not adequately treated.
In fact, once the bacilli enter the bloodstream, they can travel to almost any organ of the body, including the lymph nodes, bones and joints, skin, intestines, genital organs, kidneys, and bladder. An infection of the meninges that cover the brain causes tuberculous meningitis ; before the advent of specific drugs, this disease was always fatal, though most affected people now recover. The onset of pulmonary tuberculosis is usually insidiouswith lack of energy, weight loss, and persistent cough.
These symptoms do not subside, and the general health of the patient deteriorates. Eventually, the cough increases, the patient may have chest pain from pleurisyand there may be blood in the sputum, an alarming symptom. Fever develops, usually with drenching night sweats.
In the lung, the what are trenches and ridges consists of a collection of dead cells in which tubercle bacilli may be seen.
This lesion may erode a neighbouring bronchus or blood vesselcausing the patient to cough up blood hemoptysis. Tubercular lesions may spread extensively in the lung, causing large areas of destruction, cavities, and vy.
The amount of lung tissue available for the exchange of gases in respiration decreases, and if untreated the patient will die from failure of ventilation and general toxemia and exhaustion. Article Introduction The course of what time does the denver broncos game start today Diagnosis and treatment Other mycobacterial infections Tuberculosis through history Show more.
Videos Images. Additional Info. More About Contributors Article How to raise geese at home. Print print Print. Table Of Contents. While every effort has tubeeculosis made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate whzt manual or other sources if you have any questions.
Facebook Twitter. Give Feedback External Websites. Let us know if you have suggestions to improve this article requires login. External Websites. Articles from Britannica Encyclopedias for elementary and high school students. The Editors how to earn fast money in mumbai Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee xo areas in which they have extensive knowledge, whether from years ruberculosis experience gained by working on that content or via study for an advanced degree See Article History.
Alternative Titles: TB, consumption, phthisis, white plague. A doctor looking at the chest X-rays of patients infected with tuberculosis. Britannica Quiz. Medical Terms and Pioneers Quiz. Who discovered the major blood groups? What causes the blood disease thalassemia? Test what you know about medical science by taking this quiz. Get a Britannica Premium subscription and gain access to exclusive content.
Subscribe Now. Load Next Page.
Tuberculosis (TB), infectious disease that is caused by the tubercle bacillus, Mycobacterium tuberculosis. In most forms of the disease, the bacillus spreads slowly and widely in the lungs, causing the formation of hard nodules (tubercles) or large cheeselike masses that break down the respiratory tissues and form cavities in the lungs. Definition. Tuberculosis (TB) is a potentially fatal contagious disease that can affect almost any part of the body but is mainly an infection of the lungs. It is caused by a bacterial microorganism, the tubercle bacillus or Mycobacterium tuberculosis. When TB bacteria become active (multiplying in the body) and the immune system canТt stop the bacteria from growing, this is called TB disease. TB disease will make a person sick. People with TB disease may spread the bacteria to people with whom they spend many hours.
TB disease will make a person sick. People with TB disease may spread the bacteria to people with whom they spend many hours. It is very important that people who have TB disease are treated, finish the medicine, and take the drugs exactly as prescribed. If they stop taking the drugs too soon, they can become sick again; if they do not take the drugs correctly, the TB bacteria that are still alive may become resistant to those drugs.
TB that is resistant to drugs is harder and more expensive to treat. TB disease can be treated by taking several drugs for 6 to 9 months. There are 10 drugs currently approved by the U. Of the approved drugs, the first-line anti-TB agents that form the core of treatment regimens are:. Regimens for treating TB disease have an intensive phase of 2 months, followed by a continuation phase of either 4 or 7 months total of 6 to 9 months for treatment.
Although there are no studies that compare 5 with 7 daily doses, extensive experience indicates this would be an effective practice. DOT should be used when drugs are administered less than 7 days per week. TB control programs have administered intensive-phase regimens 5 days per week for 15 doses 3 weeks , then twice weekly for 12 doses. Note: Use of once-weekly therapy with INH mg and rifapentine mg in the continuation phase is not generally recommended. In uncommon situations where more than once-weekly DOT is difficult to achieve, once-weekly continuation phase therapy with INH mg plus rifapentine mg may be considered for use only in HIV uninfected persons without cavitation on chest radiography.
The continuation phase of treatment is given for either 4 or 7 months. The 4-month continuation phase should be used in most patients. The 7-month continuation phase is recommended only for the following groups:. Treating and curing drug-resistant TB is complicated. Inappropriate management can have life-threatening results. Drug-resistant TB should be managed by or in close consultation with an expert in the disease.
Skip directly to site content Skip directly to page options Skip directly to A-Z link. Tuberculosis TB. Section Navigation. Facebook Twitter LinkedIn Syndicate. Treatment for TB Disease. Minus Related Pages. Drug Susceptible TB Disease Treatment Regimens Regimens for treating TB disease have an intensive phase of 2 months, followed by a continuation phase of either 4 or 7 months total of 6 to 9 months for treatment.
Missed doses can lead to treatment failure, relapse, and acquired drug resistance. If doses are missed then therapy is equivalent to once weekly, which is inferior. Continuation Phase of Treatment The continuation phase of treatment is given for either 4 or 7 months.
The 7-month continuation phase is recommended only for the following groups: Patients with cavitary pulmonary TB caused by drug-susceptible organisms and whose sputum culture obtained at the time of completion of 2 months of treatment is positive; Patients whose intensive phase of treatment did not include PZA; Patients with HIV who are not receiving antiretroviral treatment ART during TB treatment; and Patients being treated with once weekly INH and rifapentine and whose sputum culture obtained at the time of completion of the intensive phase is positive.
Treatment Completion Treatment completion is determined by the number of doses ingested over a given period of time. Doses of Antituberculosis Drugs for Adults and Children external icon Note: this table is an except from Treatment of Drug-Susceptible Tuberculosis external icon and cites supporting information available in the complete guidelines.
Treatment for Drug-Resistant TB. Related Links. To receive email updates about this page, enter your email address: Email Address. What's this? Links with this icon indicate that you are leaving the CDC website. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
Tags: How to make vegan sushi, what is mast cell cancer in dogs, how to use styling wax
<- How to free a stuck engine valve - What is positive attitude definition->