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Tuberculosis

TB

Tuberculosis is a multisystemic disease commonly affecting the lungs.


Presentation

TB presents initially as flu-like symptoms. As the disease progresses, it manifests itself with chronic cough with blood-tinged sputum, fever and night sweats. Patients also complain of weight loss, malaise, retrosternal pain and weakness. There may also be cutaneous lesions. Primary infection usually persists for 7-14 days.

Extrapulmonary tuberculosis most frequently presents with lymphadenitis. It may also cause leukocytosis and anemia, however, the findings are nonspecific. Tuberculous meningitis presents with persistent headache, altered mental status which may progress to coma and low grade fever. Skeletal TB most commonly affects the spine, called Potts disease.

Fever
  • These people have a nonproductive cough, chest pain , and fever. The disease may go away and then come back at a later date.[web.archive.org]
  • We report a 9-year-old girl from Mumbai, India with fever, bilateral pleural effusion, thrombocytopaenia, haemoconcentration and oliguria due to hantavirus infection. She also had associated tuberculosis.[ncbi.nlm.nih.gov]
  • However, a new persistent fever and confused state developed 1 month after the anti-TB therapy was started.[ncbi.nlm.nih.gov]
  • After initiation of multidrug TB therapy, her fever and abdominal pain drastically improved. BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved.[ncbi.nlm.nih.gov]
  • Tuberculous meningitis presents with persistent headache, altered mental status which may progress to coma and low grade fever. Skeletal TB most commonly affects the spine, called Potts disease.[symptoma.com]
Weight Loss
  • Even then the symptoms -- loss of weight, loss of energy, poor appetite, fever , a productive cough, and night sweats -- might easily be blamed on another disease.[web.archive.org]
  • The general symptoms of TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms depend[cdc.gov]
  • loss, night sweat, and respiratory anomalies such as chronic cough, chest pain, hemoptysis or respiratory insufficiency.[orpha.net]
  • CASE PRESENTATION: A 50 year male presented with acute onset jaundice, significant weight loss and elevated liver enzymes with clinico-radiological suspicion of cholangiocarcinoma.[ncbi.nlm.nih.gov]
Weakness
  • Other people may get sick years later when their immune system becomes weak for another reason.[web.archive.org]
  • Some people develop TB disease soon after infection, while others develop TB disease later when their immune system becomes weak.[cdc.gov]
  • Disease definition Tuberculosis (TB) is a contagious-infectious disease caused mainly by Mycobacterium tuberculosis that in most individuals is usually asymptomatic but that in at risk individuals (e.g. with diabetes or with HIV infection) can cause weakness[orpha.net]
  • Some people develop active TB disease soon after infection, while others develop active TB disease later when their immune system becomes weak.[web.archive.org]
Fatigue
  • The diagnosis of miliary TB was made based on the presence of intermittent fever and fatigue; thus, anti-TB treatments (isoniazid, levofloxacin, ethambutol, and pyrazinamide) were started, which led to rapid defervescence and regression of the granular[ncbi.nlm.nih.gov]
  • Symptoms of TB in the lungs may include A bad cough that lasts 3 weeks or longer Weight loss Loss of appetite Coughing up blood or mucus Weakness or fatigue Fever Night sweats Skin tests, blood tests, x-rays, and other tests can tell if you have TB.[medlineplus.gov]
  • Fatigue and weight loss may follow. If the disease progresses and cavities form in the lungs, the person might have coughing and the production of saliva, mucus, or phlegm that may contain blood.[kidshealth.org]
  • Although TB symptoms vary depending on which part of the body the disease infects, symptoms of TB of the lungs typically include: • A bad cough lasting more than two weeks • Coughing up blood or sputum (phlegm from deep in the lungs) • Chest pain, fever, fatigue[giantmicrobes.com]
  • The general symptoms of TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms depend[cdc.gov]
Chills
  • […] vary depending on which part of the body the disease infects, symptoms of TB of the lungs typically include: • A bad cough lasting more than two weeks • Coughing up blood or sputum (phlegm from deep in the lungs) • Chest pain, fever, fatigue/weakness, chills[giantmicrobes.com]
  • The general symptoms of TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms depend[cdc.gov]
  • The general symptoms of active TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms[web.archive.org]
  • Symptoms include coughing up blood, fatigue, fever, night sweats, chills and loss of appetite. Contact reporter Nicholas Filipas at (209) 546-8257 or [email protected] Follow him on recordnet.com/filipasblog or on Twitter @nicholasfilipas.[recordnet.com]
Cough
  • Cough and difficulty breathing are less common. Generally, return of dormant tuberculosis infection occurs in the upper lungs. Symptoms include common cough with a progressive increase in production of mucus and coughing up blood.[web.archive.org]
  • The general symptoms of TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms depend[cdc.gov]
  • The general symptoms of active TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms[web.archive.org]
  • Signs and symptoms of active TB include: Coughing that lasts three or more weeks Coughing up blood Chest pain, or pain with breathing or coughing Unintentional weight loss Fatigue Fever Night sweats Chills Loss of appetite Tuberculosis can also affect[mayoclinic.com]
Pneumonia
  • Young male patient with fever and cough has a focal opacity in the left lower lobe that looks like a pneumonia. This is a case of primary tuberculosis in an adult.[emedicine.com]
  • Bacterial pneumonia in HIV-infected patients: use of the pneumonia severity index and impact of current management on incidence, aetiology and outcome. HIV Med 2008 ; 9 : 609 –615. Rabe KF, Hurd S, Anzueto A, et al.[doi.org]
  • GenIMS Investigators Understanding the inflammatory cytokine response in pneumonia and sepsis: Results of the Genetic and Inflammatory Markers of Sepsis (GenIMS) Study.[ncbi.nlm.nih.gov]
  • May result in lobar collapse, bronchiectasis, pleural effusion and pneumonia. Genitourinary : the most common site outside the lungs often presents with 'sterile' pyuria.[patient.info]
Hemoptysis
  • […] complications Hemoptysis/diagnostic imaging Hemoptysis/etiology* Homeless Persons Humans Imaging, Three-Dimensional Male Pulmonary Artery/diagnostic imaging Pulmonary Artery/microbiology Pulmonary Artery/pathology Tomography, X-Ray Computed Treatment[ncbi.nlm.nih.gov]
  • KEYWORDS: Hemoptysis; aspergilloma; blood clot; fungus ball-like shadow; lateral thoracic artery aneurysm[ncbi.nlm.nih.gov]
  • CASE PRESENTATION: We report a case of PIMT with hemoptysis. The girl was misdiagnosed with tuberculosis and treated with anti-tuberculous drugs for a long period of time.[ncbi.nlm.nih.gov]
  • […] tuberculosis that in most individuals is usually asymptomatic but that in at risk individuals (e.g. with diabetes or with HIV infection) can cause weakness, fever, weight loss, night sweat, and respiratory anomalies such as chronic cough, chest pain, hemoptysis[orpha.net]
  • The general symptoms of TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms depend[cdc.gov]
Pleural Effusion
  • We report a 9-year-old girl from Mumbai, India with fever, bilateral pleural effusion, thrombocytopaenia, haemoconcentration and oliguria due to hantavirus infection. She also had associated tuberculosis.[ncbi.nlm.nih.gov]
  • The definitive diagnosis was BTB with pleural effusion. INTERVENTIONS: Treatment with a quadruple combinational antituberculous therapy was initiated. OUTCOMES: Two months later, the patient's chest distress and discomfort significantly decreased.[ncbi.nlm.nih.gov]
  • Pleural effusions may occur and may progress to empyema.[emedicine.com]
  • KEYWORDS: Chylomicron; Chylothorax; Pleural effusion; Tuberculosis[ncbi.nlm.nih.gov]
Productive Cough
  • CASE PRESENTATION: A 6-year old male infant from the West Region of Cameroon infected with HIV who presented at a local health center with a 10 days history of productive cough associated with nocturnal fever and abdominal pains non responsive to broad[ncbi.nlm.nih.gov]
  • Even then the symptoms -- loss of weight, loss of energy, poor appetite, fever , a productive cough, and night sweats -- might easily be blamed on another disease.[web.archive.org]
  • Symptoms include productive cough, fever, weight loss, and malaise. Diagnosis is most often by sputum smear and culture and, increasingly, by rapid molecular-based diagnostic tests.[merckmanuals.com]
  • Even then the symptoms -- loss of weight, loss of energy, poor appetite, fever , a productive cough , and night sweats -- might easily be blamed on another disease.[emedicinehealth.com]
  • ., a productive cough, night sweats, fever, weakness or fatigue, weight loss, pain in the chest); and can have a positive tuberculin skin test reaction. 5 Infection Control/Precautions In 2005, the CDC developed guidelines for preventing transmission[ada.org]
Loss of Appetite
  • This is called miliary tuberculosis and produces fever, weakness, loss of appetite, and weight loss . Cough and difficulty breathing are less common. Generally, return of dormant tuberculosis infection occurs in the upper lungs.[web.archive.org]
  • CASE PRESENTATION: We report a case of a 56-year-old Sri Lankan Sinhalese man who presented with pyrexia of known origin with significant loss of weight and loss of appetite. He had mild pallor with mild hepatosplenomegaly.[ncbi.nlm.nih.gov]
  • Symptoms of TB in the lungs may include A bad cough that lasts 3 weeks or longer Weight loss Loss of appetite Coughing up blood or mucus Weakness or fatigue Fever Night sweats Skin tests, blood tests, x-rays, and other tests can tell if you have TB.[medlineplus.gov]
  • […] of appetite, and night sweats Both active and latent TB can be detected by injecting tuberculin under the skin and examining resultant bumps.[giantmicrobes.com]
  • The general symptoms of TB disease include Unexplained weight loss Loss of appetite Night sweats Fever Fatigue Chills The symptoms of TB of the lungs include Coughing for 3 weeks or longer Hemoptysis (coughing up blood) Chest pain Other symptoms depend[cdc.gov]
Abdominal Pain
  • PATIENT CONCERNS: A 58-year-old Asian woman was referred to our hospital for evaluation of low back pain for 4 years and abdominal pain for 1 month.[ncbi.nlm.nih.gov]
  • After initiation of multidrug TB therapy, her fever and abdominal pain drastically improved. BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved.[ncbi.nlm.nih.gov]
  • Abstract A 46-year-old woman who had a recent total abdominal hysterectomy presented with a 1 month history of lower abdominal pain, 1 week of nausea and vomiting as well as decreased urinary output preceded by a year of significant unintentional weight[ncbi.nlm.nih.gov]
  • CASE PRESENTATION: A 6-year old male infant from the West Region of Cameroon infected with HIV who presented at a local health center with a 10 days history of productive cough associated with nocturnal fever and abdominal pains non responsive to broad[ncbi.nlm.nih.gov]
  • Symptoms depend on the affected areas of the body and can include: Abdominal pain or swelling Chills Cough and shortness of breath Fatigue Fever General discomfort, uneasiness, or ill feeling ( malaise ) Joint pain Pale skin due to anemia (pallor) Sweating[nlm.nih.gov]
Vomiting
  • Abstract A 46-year-old woman who had a recent total abdominal hysterectomy presented with a 1 month history of lower abdominal pain, 1 week of nausea and vomiting as well as decreased urinary output preceded by a year of significant unintentional weight[ncbi.nlm.nih.gov]
  • Common side effects include: upset stomach, nausea and vomiting or loss of appetite. tingling or numbness in the hands or feet itchy skin, rashes or bruising changes in your eyesight or blurred visions yellowish skin or eyes dark-colored urine weakness[lung.org]
  • Tell your doctor or health care worker if you have unexplained illness or any of the following symptoms happen: nausea and/or vomiting jaundice - yellow skin or eyes, dark urine unexplained fever or tiredness tingling or numbness of hands or feet or joint[nt.gov.au]
  • On the sixteenth, vomited pretty frequently yellow, bilious matters.[ebooks.adelaide.edu.au]
  • Call your doctor immediately if you have any of these symptoms: Nausea Vomiting Abdominal pain, tenderness or soreness Blurry vision or color-blindness Dark (coffee-colored) urine Fever that lasts 3 days or longer Jaundice (the yellowing of the skin and[familydoctor.org]
Nausea
  • Abstract A 46-year-old woman who had a recent total abdominal hysterectomy presented with a 1 month history of lower abdominal pain, 1 week of nausea and vomiting as well as decreased urinary output preceded by a year of significant unintentional weight[ncbi.nlm.nih.gov]
  • Common side effects include: upset stomach, nausea and vomiting or loss of appetite. tingling or numbness in the hands or feet itchy skin, rashes or bruising changes in your eyesight or blurred visions yellowish skin or eyes dark-colored urine weakness[lung.org]
  • TB of the brain can cause headaches and nausea. You won’t have any symptoms of tuberculosis unless you have active TB. What causes tuberculosis? TB is caused by bacteria. The bacteria spread through the air from one person to another.[familydoctor.org]
  • Tell your doctor or health care worker if you have unexplained illness or any of the following symptoms happen: nausea and/or vomiting jaundice - yellow skin or eyes, dark urine unexplained fever or tiredness tingling or numbness of hands or feet or joint[nt.gov.au]
  • At the commencement he was troubled with nausea and cardialgia; thirsty, tongue was parched; urine thin and dark.[ebooks.adelaide.edu.au]
Back Pain
  • PATIENT CONCERNS: A 58-year-old Asian woman was referred to our hospital for evaluation of low back pain for 4 years and abdominal pain for 1 month.[ncbi.nlm.nih.gov]
  • For example, tuberculosis of the spine may give you back pain, and tuberculosis in your kidneys might cause blood in your urine.[mayoclinic.com]
  • TB of the spine can cause back pain and leg paralysis. TB of the brain can cause headaches and nausea. You won’t have any symptoms of tuberculosis unless you have active TB. What causes tuberculosis? TB is caused by bacteria.[familydoctor.org]
  • Some of the common reasons to order a chest X-ray test are listed below: Cough Shortness of breath Chest pain Poor oxygenation (hypoxia) Back pain Chest injury Fever From Reviewed on 10/19/2018 Sources: Patient Comments & Reviews CONTINUE SCROLLING FOR[emedicinehealth.com]
  • pain or stiffness Lower-extremity paralysis, in as many as half of patients with undiagnosed Pott disease Tuberculous arthritis, usually involving only 1 joint (most often the hip or knee, followed by the ankle, elbow, wrist, and shoulder) Symptoms of[emedicine.medscape.com]
Arthralgia
  • Monitoring Persons receiving bedaquiline should be monitored weekly for nausea, headache, hemoptysis, chest pain, arthralgia and rash, and treatment should be modified as clinically indicated.[cdc.gov]
  • The most common side effects with Sirturo (which may affect more than 1 in 10 people) are headache, dizziness, nausea (feeling sick), vomiting, and arthralgia (joint pain).[ema.europa.eu]
  • The Uganda study reported that persons taking the three-drug, pyrazinamide-containing regimen had higher rates of paresthesias, arthralgias, and significant increases in serum AST ( 84 ).[web.archive.org]
Night Sweats
  • Even then the symptoms -- loss of weight, loss of energy, poor appetite, fever , a productive cough, and night sweats -- might easily be blamed on another disease.[web.archive.org]
  • sweat, and respiratory anomalies such as chronic cough, chest pain, hemoptysis or respiratory insufficiency.[orpha.net]
  • TB affecting the lungs presents with chronic cough with sputum, chest pain, fever, night sweats and weight loss. Skeletal TB presents with body aches, musculoskeletal pain and joint pain.[symptoma.com]
  • Symptoms of TB in the lungs may include A bad cough that lasts 3 weeks or longer Weight loss Loss of appetite Coughing up blood or mucus Weakness or fatigue Fever Night sweats Skin tests, blood tests, x-rays, and other tests can tell if you have TB.[medlineplus.gov]
  • sweats Both active and latent TB can be detected by injecting tuberculin under the skin and examining resultant bumps.[giantmicrobes.com]
Flank Pain
  • pain Dysuria Frequent urination In men, a painful scrotal mass, prostatitis, orchitis, or epididymitis Symptoms of gastrointestinal TB are referable to the infected site and may include the following: Nonhealing ulcers of the mouth or anus Difficulty[emedicine.medscape.com]
Strangury
  • But, with regard to the strangury itself, the symptoms were protracted and painful. Their urine was copious, thick, of various characters, red, mixed with pus, and was passed with pain.[ebooks.adelaide.edu.au]
Headache
  • Tuberculous meningitis presents with persistent headache, altered mental status which may progress to coma and low grade fever. Skeletal TB most commonly affects the spine, called Potts disease.[symptoma.com]
  • This can cause a lasting or intermittent headache that occurs for weeks. Mental changes also are possible. Liver or kidney problems. Your liver and kidneys help filter waste and impurities from your bloodstream.[mayoclinic.com]
  • TB of the brain can cause headaches and nausea. You won’t have any symptoms of tuberculosis unless you have active TB. What causes tuberculosis? TB is caused by bacteria. The bacteria spread through the air from one person to another.[familydoctor.org]
  • Monitoring Persons receiving bedaquiline should be monitored weekly for nausea, headache, hemoptysis, chest pain, arthralgia and rash, and treatment should be modified as clinically indicated.[cdc.gov]
  • The most common side effects with Sirturo (which may affect more than 1 in 10 people) are headache, dizziness, nausea (feeling sick), vomiting, and arthralgia (joint pain).[ema.europa.eu]
Altered Mental Status
  • Tuberculous meningitis presents with persistent headache, altered mental status which may progress to coma and low grade fever. Skeletal TB most commonly affects the spine, called Potts disease.[symptoma.com]

Workup

Laboratory tests

Screening:

  • Tuberculin skin test (using PPD)
  • Interferon-Gamma release Assay (IGRA): IGRA assays offer certain advantages over tuberculin skin testing [6].

Suspected TB:

  • Acid-fast staining of sputum or other specimens
  • Culture in Lowenstein-Jensen agar
  • Nucleic acid amplification tests
  • Luciferase Assay which can detect drug resistant organisms [2]
  • HIV serology

Imaging

Imaging studies include chest radiography and CT scan which can show pulmonary infiltrates. A biopsy can be performed, but is rarely needed.

Test results

On the basis of clinical evaluation and laboratory test results, TB can be definitively diagnosed. Susceptible individuals should also be screened for latent TB. The goal of testing for latent tuberculosis infection (LTBI) is to identify individuals who are at increased risk for the development of tuberculosis (TB) and therefore would benefit from treatment of LTBI [7].

Pericardial Effusion
  • This paper reports a case of tuberculosis-associated pericardial effusion with dense fibrinous material not causing tamponade in a foreigner presenting with nonspecific symptoms.[ncbi.nlm.nih.gov]
  • Pericardial : initially nonspecific; may be signs of pericardial effusion (pulsus paradoxus, elevated JVP) or constrictive pericarditis.[patient.info]
Pyuria
  • We present a case of a 47-year-old African-American woman with relapsing urinary infection and sterile pyuria. After a 4 four-year evolution, the patient developed functional exclusion of the right kidney as a consequence of chronic pyelonephritis.[dx.doi.org]
  • Urinary Tract Tuberculosis: A "sterile pyuria" with WBC's present in urine but a negative routine bacterial culture may suggest the diagnosis of renal tuberculosis. Progressive destruction of renal parenchyma occurs if not treated.[library.med.utah.edu]
  • Genitourinary : the most common site outside the lungs often presents with 'sterile' pyuria. There may be kidney lesions, salpingitis, abscesses and infertility in females and swelling of the epididymis in males.[patient.info]
  • […] radiographic findings, reflecting an inability of the impaired immune response to contain infection.(49) Patients with extrapulmonary TB may present with signs and symptoms specific to the involved site, such as lymphadenopathy, headache, meningismus, pyuria[hivinsite.org]
Pseudomonas
  • Urinary nitrate was first reduced to nitrite using the enzyme nitrate reductase of Pseudomonas oleovorans as described ( 14 ). Nitrite content was determined by the Griess reaction ( 8 ).[dx.doi.org]
Pleural Effusion
  • We report a 9-year-old girl from Mumbai, India with fever, bilateral pleural effusion, thrombocytopaenia, haemoconcentration and oliguria due to hantavirus infection. She also had associated tuberculosis.[ncbi.nlm.nih.gov]
  • The definitive diagnosis was BTB with pleural effusion. INTERVENTIONS: Treatment with a quadruple combinational antituberculous therapy was initiated. OUTCOMES: Two months later, the patient's chest distress and discomfort significantly decreased.[ncbi.nlm.nih.gov]
  • Pleural effusions may occur and may progress to empyema.[emedicine.com]
  • KEYWORDS: Chylomicron; Chylothorax; Pleural effusion; Tuberculosis[ncbi.nlm.nih.gov]

Treatment

Medication

Anti-tuberculous chemotherapy is the mainstay of treatment and highly effective. The most commonly used antibiotics used are isoniazid (INH) and rifampicin. The recommended treatment of new-onset pulmonary tuberculosis, as of 2010, is 6 months of a combination of antibiotics containing rifampicin, isoniazid, pyrazinamide, and ethambutol for the first two months [8]. Only rifampicin and isoniazid need to be continued for the last four months.

Directly observed therapy

Patient compliance is generally found to be non satisfactory. To overcome this hurdle, directly observed therapy (DOT) has become an important part of treatment. Individual case management with DOT is very important for facilitating adherence and preventing the development of drug resistance and represents the standard of care in the United States today [9].

Prognosis

TB infection does not always progress to active TB disease, but since both active and latent TB responds well to antituberculous chemotherapy, it has an excellent prognosis. Identification and treatment of latent tuberculosis infection can reduce the risk of development of disease by as much as 90 percent [5].

Etiology

Mycobacterium tuberculosis

The primary causative agent of tuberculosis is the slender, rod-shaped obligate aerobe called Mycobacterium tuberculosis (other mycobacteria can also cause this disease). It is acid-fast due to the high lipid content (up to 60%) of their cell walls. 3 important constituents include [2]:

  • Long-chain fatty acids (C78-C90) called Mycolic acids which contribute to the acid-fastness.
  • Wax D serves to enhance the immune response. 
  • Phosphatides play a role in caseous necrosis.

Transmission

TB is an air-borne infection. It can be transmitted by coughing, sneezing, spitting and even speaking by a person with an active infection. All such actions result in expulsion of infectious aerosol particles or droplets that contain the bacteria which may be inhaled by anyone present in the vicinity. Since the infectious dose of TB is very low, inhalation of as little as 10 organisms can lead to the development of this disease. People in close contact with such a person are particularly at high risk.

Genetics

Many patients are genetically vulnerable to this disease. Polymorphisms in some genes, for example in NRAMP1 gene which encodes the NRAMP1 transmembrane protein that pumps divalent ions out of lysosomes, may result in ineffectual immune response of the host. NRAMP1 may inhibit microbacterial growth by limiting availability of ions needed by the bacteria [3]. So a genetic defect in this gene may make the host vulnerable to TB.

Epidemiology

Incidence

TB is estimated to affect 1.7 billion individuals worldwide with approximately 1.6 million deaths annually. 

Age

Tuberculosis is typically a disease of older people. Immuno-compromised individuals, however, are at risk, irrespective of age.

Sex

The disease is found more in males than in females.

Race

TB is prone to develop in poverty stricken areas and so, in many regions of various third world countries this disease is a common occurrence. It has the highest occurrence in Asians, followed by Hispanics and then African-Americans. 

Sex distribution
Age distribution

Pathophysiology

Mycobacterium tuberculosis enters macrophages by endocytosis mediated by several factors. Once inside, it begins to replicate in the pulmonary airspaces and alveolar macrophages. Despite bacteremia, most patients at this stage are asymptomatic. About 3 weeks after infection, a T-H1 response is mounted that activates macrophages to become bactericidal [4]. The activated T-H1 cells produce Interferon gamma which is critical in containing the infection. NK-1 cells also produce IFN-y. IFN-y enables macrophages to differentiate into epitheloid histiocytes which are characteristic findings of granulomas. Caseous necrosis ensues in an attempt to close off and destroy the bacteria.

The primary formed lesions are 1-1.5 cm areas of inflammation with consolidation called Ghon focus. They begin to caseate and some of the bacteria disseminate into regional lymph nodes. This caseated lesion along with lymph node involvement constitutes the Ghon complex. In subsequent weeks the tubercle bacteria disseminate to the rest of the body via both lymphatic and hematogeneous spread. The Ghon complex undergoes progressive fibrosis turning into calcified lesions called Ranke complex.

All this results in three major effects: Reduced breathing and vital capacity, reduced total respiratory membrane surface area and increased thickness of the respiratory membrane, and lastly, abnormal ventilation-perfusion ratio of the lung.

Prevention

TB can be prevented with the use of BCG vaccine. This vaccine contains a strain of live, attenuated Mycobacterium bovis called bacillus Calmette-Guerin. It can also be prevented by living in well-aired, less crowded quarters and using boiled water and pasteurized milk. The PPD screening test should also be regularly performed in people belonging to susceptible demographics.

Summary

Tuberculosis (TB) is a multisystemic disease commonly affecting the lungs. It is due to an infection by bacteria of the Mycobacteria genus. It is transmitted when people who have an active TB infection cough, sneeze, or otherwise transmit respiratory fluids through the air [1]. It is one of the most common infectious diseases in the world and a source of high infection-associated mortality, second only to HIV. The World Health Organization is still attempting to eradicate the disease from the world and has been quite successful in significantly decreasing the incidence of TB in many developed countries.

Patient Information

Definition

Tuberculosis (TB) is an infectious disease that occurs due to transmission of bacteria from a person with an active TB infection to a healthy individual. Patients that are immune-compromised, for e.g HIV patients, are at higher risk of contracting this disease. 

Cause

TB is most commonly due to an infection by Mycobacterium tuberculosis. Other strains like Mycobacterium bovis may also cause TB. Transmission is through air, like during coughing or sneezing via aerosol droplets containing the infectious particles. 

Signs and symptoms

Signs and symptoms vary according to the type of TB. TB affecting the lungs presents with chronic cough with sputum, chest pain, fever, night sweats and weight loss. Skeletal TB presents with body aches, musculoskeletal pain and joint pain. Tuberculous meningitis presents with headache, altered mental status, fever and sometimes coma.

Diagnosis

Diagnostic evaluation for TB may be initiated in outpatient settings [10]. Patients that are susceptible to this disease should be screened. Diagnosis is made based on history, chest radiography and positive blood/sputum cultures. 

Treatment

Treatment is ideally a quadruple therapy of antibiotics that should be continued for 6 months to prevent recurrence.

References

Article

  1. Konstantinos A. Testing for tuberculosis. Australian Prescriber 33 (1): 12–18, 2010.
  2. Warren Levinson: Review of Medical Microbiology and Immunology. 11th ed. Pa: McGraw Hill, 2010. ISBN 978-0-07-170028-3
  3. Cellier MF, et al. NRAMP1 phagocyte intracellular metal withdrawal defense. Microbes Infect 9:1662, 2007.
  4. Flynn JL, Chan J. Immunology of tuberculosis. Annu Rev Immunol 19:93, 2001.
  5. Comstock GW. How much isoniazid is needed for prevention of tuberculosis among immunocompetent adults? Int J Tuberc Lung Dis 1999; 3:847.
  6. Mazurek GH, Jereb J, Lobue P, Iademarco MF, Metchock B, Vernon A. Guidelines for using the QuantiFERON-TB Gold test for detecting Mycobacterium tuberculosis infection, United States. MMWR Recomm Rep. Dec 16 2005;54:49-55
  7. Mancuso JD, Tribble D, Mazurek GH, et al. Impact of targeted testing for latent tuberculosis infection using commercially available diagnostics. Clin Infect Dis 2011; 53:234.
  8. Lawn SD, Zumla AI. Tuberculosis. Lancet 378 (9785): 57–72. 2 July 2011 doi:10.1016/S0140-6736(10)62173-3. PMID 21420161
  9. Blumberg HM, Burman WJ, Chaisson RE, et al. American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: treatment of tuberculosis. Am J Respir Crit Care Med 2003; 167:603.
  10. Taylor Z, Marks SM, Ríos Burrows NM, et al. Causes and costs of hospitalization of tuberculosis patients in the United States. Int J Tuberc Lung Dis 2000; 4:931.

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Last updated: 2018-01-17 10:34