Mycobacterium tuberculosis is the causative agent of pulmonary tuberculosis, a highly contagious infectious disease that is characterized by a granulomatous inflammation of the lungs. The disease may spread to other organs and requires a long-term antibiotic treatment.
Presentation
Even in cases of active pulmonary TB, symptoms are rather unspecific. The most common symptom is cough. Furthermore, patients suffer from general discomfort, fatigue, anorexia and weight loss [11]. Fever may be observed, but is not always present.
Cough is initially only productive after waking up in the morning but becomes more productive as the disease progresses. The sputum is usually of yellowish or greenish color. If the disease does progress to cavitary pulmonary TB, an extensive necrosis with cavitation, the inflammation may damage vessels and hemoptysis may occur [12].
Extensive lung damage, pneumothorax or pleural effusion may lead to dyspnea.
HIV patients may not show typical pulmonary TB symptoms due to their impaired immune system. Pulmonary TB tends to spread in these patients and extrapulmonary symptoms may then be present.
Immune System
- Splenomegaly
USG abdomen showed a liver of normal size and echo pattern with intrahepatic biliary radicle dilatation (IHBRD) in the left lobe, splenomegaly (18 cm), normal common bile duct and gallbladder with minimal free fluid. There were no focal lesions. [termedia.pl]
Physical findings are also variable and in descending order of frequency are: fever, wasting, hepatomegaly, pulmonary findings, lymphadenopathy, splenomegaly. [southsudanmedicaljournal.com]
Entire Body System
- Fever
Post-operative fever is common following emergency surgery. Investigation and management of post-operative fever can be challenging when a clear source of sepsis is not evident or the underlying source of infection is not recognised. [ncbi.nlm.nih.gov]
- Weight Loss
The first case was a 13-year-old patient who was admitted with a 2-month history of fever, weight loss, night sweats, and cough. [ncbi.nlm.nih.gov]
Several factors were associated with an increased risk of tuberculosis, such as male gender, having a smoking history, liver cirrhosis, or subjective body weight loss. [diabetesincontrol.com]
- Fatigue
She also had evening low-grade fever and fatigue since she arrived. Her mother-in-law had died of tuberculosis two years before. Chest radiography and computed tomography scan showed a left upper lobe consolidation. [ncbi.nlm.nih.gov]
• Fatigue. • Fever. • Weight loss. • Wheezing. Click to receive news links via WhatsApp. Or for the latest news, visit our webpage or follow us on Facebook and Twitter [estcourtnews.co.za]
In addition, the symptoms can be vague, including only mild fatigue and cough. [mdedge.com]
- Anemia
[…] dysphagia, iron deficiency anemia and esophageal webs. [scielo.br]
Clinical features of iron deficiency anemia and barium swallow showing the typical post cricoids web confirms the diagnosis. [elsevier.es]
Direct Coombs' test was positive with mild anemia and the cold agglutinin titer was high. Sputum showed numerous acid fast bacilli per high power field. [ncbi.nlm.nih.gov]
Peripheral smear study revealed microcytic, hypochromic anemia and laboratory investigations were significant for a profound iron deficiency anemia (Table 1). [hindawi.com]
- Anorexia
Abstract A 53-year-old man with a significant smoking history presented with chronic cough, exertional breathlessness, intermittent fever, weight loss and anorexia. [ncbi.nlm.nih.gov]
Reactivation of Pulmonary Tuberculosis often begins insidiously with non-specific constitutional symptoms such as fever, anorexia, weight loss, and characteristically night sweats. [pathwaymedicine.org]
Among adult tuberculosis patients, the percentages of symptoms reported for cough more than 2 weeks, chest pain, anorexia, and body weight loss were 48.2%, 41.0%, 40.6%, and 44.5%, respectively. [diabetesincontrol.com]
It has been suggested that leptin mediates anorexia in chronic inflammatory states ( 11 ). [academic.oup.com]
Anorexia. Dyspepsia. Apical "crackles". Hyponatraemia/ hypokalaemia. [aic.cuhk.edu.hk]
Respiratoric
- Cough
The first case was a 13-year-old patient who was admitted with a 2-month history of fever, weight loss, night sweats, and cough. [ncbi.nlm.nih.gov]
Affected people may suffer from overall discomfort, loss of appetite, loss of body weight and cough. Fever may be present, but not necessarily. Some more severe cases are associated with difficulties to breathe, coughing up blood and chest pain. [symptoma.com]
Symptoms of active, pulmonary TB include: A cough that lasts for more than three weeks A cough that produces green or yellow sputum (phlegm) that may also be streaked with blood Shortness of breath or chest pain Fatigue Loss of appetite and weight loss [copd.about.com]
When symptoms of pulmonary TB occur, they can include: • Breathing difficulty. • Chest pain. • Cough (usually with mucus). • Coughing up blood. • Excessive sweating, especially at night. • Fatigue. • Fever. • Weight loss. • Wheezing. [estcourtnews.co.za]
- Pleural Effusion
He was admitted for progression of left pleural effusion and consolidation in the left upper lobe. [ncbi.nlm.nih.gov]
If you think somebody's got pleural TB with an effusion, pleural biopsy certainly should be done. [khanacademy.org]
effusion in postprimary TB almost always means direct spread of the disease into the pleural cavity and should be regarded as an empyema —this carries a graver prognosis than the pleural effusion of the primary form Direct extension into the ribs or [learningradiology.com]
- Hemoptysis
Massive hemoptysis is a life-threatening complication of pulmonary tuberculosis. In the presence of pulmonary tuberculosis, massive hemoptysis can result from a number of different causes, with an artery aneurysm being rarely reported. [ncbi.nlm.nih.gov]
- Productive Cough
A 37 year old Sri Lankan Sinhalese female presented with fever of one month's duration with productive cough and two weeks painless left lower limb swelling. [ncbi.nlm.nih.gov]
Symptoms include productive cough, night sweats, fever, weight loss, and weakness. There may be hemoptysis (coughing up blood). Patients with cavitary TB are highly contagious. [healthcommunities.com]
She complaints of productive cough of three week’s duration with no history of haemoptysis or breathlessness. Fever was associated with anorexia and weight loss. [bmcresnotes.biomedcentral.com]
A productive cough which is often blood-stained may also be present 1. Occasionally patients may present with massive hemoptysis due to an erosion of a bronchial artery 1,3. [radiopaedia.org]
- Persistent Cough
When your immune system isn't strong enough to do so, latent TB becomes active TB, the most common symptom of which is a persistent cough that may produce blood-tinged phlegm. [copd.about.com]
TB that affects the lungs (pulmonary TB) Most TB infections affect the lungs, which can cause: a persistent cough that lasts more than three weeks and usually brings up phlegm, which may be bloody breathlessness that gradually gets worse TB outside the [nhs.uk]
A person with active TB disease may have any or all of the following symptoms: A persistent cough Constant fatigue Weight loss Loss of appetite Fever Coughing up blood Night sweats These symptoms can also occur with other diseases so it is important to [lung.org]
The body reacts to inflammation by trying to eliminate the particle that caused it – if this happens in the airway, the easiest way to eliminate the cause is to cough it up. Initially, people with pulmonary TB have a dry, persistent cough. [tbonline.info]
Cardiovascular
- Chest Pain
Acute virus myocarditis presents with a wide range of symptoms, from mild dyspnea or chest pain to cardiogenic shock and death. A 26-year-old Caucasian man non-smoker presented with one-week history of lower extremities’ swelling. [ncbi.nlm.nih.gov]
When to See a Doctor If you have been exposed to someone with TB, have chest pain or a persistent cough with or without phlegm, call your doctor, who will give you a skin test. TB is a serious illness and can be fatal if not treated. [copd.about.com]
We describe here a case of a young woman presenting with acute onset of chest pain, ST elevation on ECG, elevated cardiac enzymes and active pulmonary tuberculosis. [casesjournal.biomedcentral.com]
• Chest pain. • Cough (usually with mucus). • Coughing up blood. • Excessive sweating, especially at night. • Fatigue. • Fever. • Weight loss. • Wheezing. Click to receive news links via WhatsApp. [estcourtnews.co.za]
Get medical help right away if you have chest pain. Who’s at Risk? You’re more likely to get TB if you come into contact with others who have it. [webmd.com]
- Tachycardia
Symptoms resulting from anemia (weakness, pallor, fatigue, tachycardia) may dominate the clinical picture. Additional features are glossitis, angular cheilitis and koilonychia. Enlargement of the spleen and thyroid may also be observed. [orpha.net]
There may be pallor and even tachycardia if anaemia is marked. There may be koilonychia (spoon-shaped nails), angular cheilitis and glossitis. Investigation FBC will show a microcytic, hypochromic anaemia. Ferritin is low. [patient.info]
Symptoms resulting from anemia such as weakness, pallor, fatigue and tachycardia may dominate the clinical picture. Furthermore, it is characterized by glossitis, angular cheilitis and koilonychia (spoon-shaped finger nails). [ncbi.nlm.nih.gov]
Patients also usually complain of anemic symptoms such as weakness, pallor, fatigue, and tachycardia. [hindawi.com]
[…] had a history of seizures, 4 did not return in order to undergo randomization, 3 weighed less than 35 kg, 1 had extra-pulmonary tuberculosis, 1 had no firm address, 1 was younger than 18 years of age, 1 was receiving antiretroviral therapy, and 1 had tachycardia [nejm.org]
Skin
- Night Sweats
The first case was a 13-year-old patient who was admitted with a 2-month history of fever, weight loss, night sweats, and cough. [ncbi.nlm.nih.gov]
Patients are also likely to manifest night sweats accompanied by chills and fever. Patients also suffer from a persistent sense of weakness and fatigue. [epainassist.com]
Reactivation of Pulmonary Tuberculosis often begins insidiously with non-specific constitutional symptoms such as fever, anorexia, weight loss, and characteristically night sweats. [pathwaymedicine.org]
Symptoms may include fever, night sweats, and weight loss. It can be difficult to diagnose because the initial chest x-ray may be normal. [healthcommunities.com]
The symptoms of active disease include cough, blood in sputum, night sweating, fatigue and severe weight loss. No specific guidelines for nutrition recommendations for these patients exist. [livestrong.com]
Workup
Patients usually present with unspecific general or respiratory symptoms that prompt radiographic imaging of the chest.
If lung alterations are detected, the suspected diagnosis may be further corroborated by a medical history of possible exposure to M. tuberculosis, by presence of chronic cough, weight loss and lymphadenopathy.
Sputum should be examined and cultured [2]. While a positive tuberculin skin test or an interferon-γ release assay may be conducted after possible exposure and initiate TB diagnosis, these tests may also be carried out in order to confirm a hypothetically existent diagnosis [7]. Unclear cases may benefit from molecular biological diagnostic techniques such as PCR [13].
After TB diagnosis, the patient should be tested for immunosuppressive conditions such as HIV. Also, hepatic and renal functions should be checked.
Skin Test
- Skin Test Positive
In addition, men are more likely than women to have a positive tuberculin skin test result. The reason for these differences may be social, rather than biologic, in nature. [emedicine.medscape.com]
X-Ray
- Pulmonary Infiltrate
This case report highlights the risk of misdiagnosis in patients with generalized lympho-adenopathy and pulmonary infiltrates, particularly in Africans young patients. Copyright © 2018. Published by Elsevier Ltd. [ncbi.nlm.nih.gov]
Considering presence of pulmonary infiltrate that accompanied the cavity lesions, we found that 105 patients (68.6%) of our sample had the presence of pulmonary infiltrate. [scielo.br]
TB is characterized by pulmonary infiltrates, formation of granulomas with caseation, fibrosis, and cavitation. People living in crowded and poorly ventilated conditions and who are immunocompromised are most likely to become infected. [nurseslabs.com]
[…] or miliary pattern infiltrates. [journals.lww.com]
- Pulmonary Infiltrates
This case report highlights the risk of misdiagnosis in patients with generalized lympho-adenopathy and pulmonary infiltrates, particularly in Africans young patients. Copyright © 2018. Published by Elsevier Ltd. [ncbi.nlm.nih.gov]
Considering presence of pulmonary infiltrate that accompanied the cavity lesions, we found that 105 patients (68.6%) of our sample had the presence of pulmonary infiltrate. [scielo.br]
TB is characterized by pulmonary infiltrates, formation of granulomas with caseation, fibrosis, and cavitation. People living in crowded and poorly ventilated conditions and who are immunocompromised are most likely to become infected. [nurseslabs.com]
[…] or miliary pattern infiltrates. [journals.lww.com]
- Atelectasis
[…] age older than 60 years (HR: 3.18; 95% CI: 1.66-6.10), complication with bacterial pneumonia (HR: 2.64; 95% CI: 1.30-5.35), diagnosis delay (HR: 2.60; 95% CI: 1.42-4.78), CD4 + T cell count less than 50/mm 3 (HR: 2.38; 95% CI: 1.27-4.43) and pulmonary atelectasis [ncbi.nlm.nih.gov]
[…] age should strongly suggest TB Lymph node § Mostly unilateral hilar and/or paratracheal, usually right sided, rarely bilateral § Differentiates primary from postprimary TB—it does not occur in postprimary TB § Much more common in children · Airway · Atelectasis [learningradiology.com]
Occasionally these nodes may be large enough to compress adjacent airways resulting in distal atelectasis 1. Pleural effusions are more frequent in adults, seen in 30-40% of cases, whereas they are only present in 5-10% of pediatric cases 1. [radiopaedia.org]
Compression of airways by enlarged lymph nodes may cause atelectasis and is more common in children. [southsudanmedicaljournal.com]
- Cavitary Lesion
Computed tomography chest with contrast identified a large cavitary lesion in the right upper lobe (RUL). [ncbi.nlm.nih.gov]
[…] hemorrhage Extensive intracavitary hemorrhage HEALING OF CAVITARY LESIONS: With control of the infection and elimination of tubercle bacilli cavitary lesions undergo a healing process which results in their linings undergoing transformation to scar tissue [granuloma.homestead.com]
cavitary wall, caseum, and cellular components of lesions. [aac.asm.org]
In countries with a low TB burden, the percentage of advanced pulmonary TB with positive sputum smear and cavitary lesions steadily increased due to declining clinicians’ vigilance to the presentations of TB and a lack of efficient diagnostic tools to [bmcinfectdis.biomedcentral.com]
- X-Ray Abnormal
Chest X-ray and echocardiography were done that morning. Chest X-ray discovered homogenous shades, well defined, of solid tissue intensity, located mainly in the para-tracheal part of the left lung (figure 3 ). Figure 3 Chest X-ray. [casesjournal.biomedcentral.com]
Radiographic features Chest X-ray abnormalities are nearly always found. However in the presence of HIV infection, a normal X-ray is more common. [southsudanmedicaljournal.com]
Serum
- Hyponatremia
Blood tests showed iron deficiency anemia, prolonged bleeding time, and mild hyponatremia. [ncbi.nlm.nih.gov]
Hyponatremia, which may occur in 11% of patients [8], is caused by the production of an antidiuretic hormone-like substance in affected lung tissue [9]. [southsudanmedicaljournal.com]
- Thrombocytosis
Cytokines are responsible for clinical and laboratory alterations which occur during the inflammatory process, such as fever, leukocytosis, thrombocytosis, and acute-phase hepatic responses (2). [scielo.br]
Hypercoagulability in tuberculosis is attributed to decreased antithrombin lll and protein C, elevated plasma fibrinogen level, increased platelet aggregation and reactive thrombocytosis [ 7, 8 ]. [bmcresnotes.biomedcentral.com]
- Neutropenia
Neutropenia with each standard antituberculosis drug in the same patient. Br. Med. J. 280:1064-1070, 1980. Turaut M, Uzun O, Kelkitli E, et al. Pulmonary tuberculosis associated with autoimmune hemolytic anemia: An unusual presentation. [siicsalud.com]
The fifth patient experienced an episode of febrile neutropenia with pneumonia during consolidation chemotherapy and sputum cultures obtained during this period yielded M. tuberculosis, which had been reported 1 month after BMT. [nature.com]
- Lymphocytosis
CNS Tuberculosis: A meningeal pattern of spread can occur, and the cerebrospinal fluid typically shows a high protein, low glucose, and lymphocytosis. The base of the brain is often involved, so that various cranial nerve signs may be present. [library.med.utah.edu]
Microbiology
- Acid-Fast Bacilli in the Sputum
BAL was performed in 228 of the 347 patients with chest X-ray suggestive of PT and negative acid-fast bacilli (AFB) in sputum (or missing specimen) for determination of M. tuberculosis -specific ELISpot (T-SPOT.TB test) and amplification of M. tuberculosis [archbronconeumol.org]
[…] granulomas or acid-fast bacilli in tissue specimens). [scielo.br]
Other Pathologies
- Granulomatous Tissue
Oral ex- amination revealed ulcerative and granulomatous lesions on the soft palate and tonsils. Histological examination of the lesions showed granulomatous tissue with caseaous necrosis consistent with tuberculosis. [ncbi.nlm.nih.gov]
The percent of granulomatous tissue was calculated as a percent of total lung area as described 61. [nature.com]
Pleura
- Pleural Effusion
He was admitted for progression of left pleural effusion and consolidation in the left upper lobe. [ncbi.nlm.nih.gov]
If you think somebody's got pleural TB with an effusion, pleural biopsy certainly should be done. [khanacademy.org]
effusion in postprimary TB almost always means direct spread of the disease into the pleural cavity and should be regarded as an empyema —this carries a graver prognosis than the pleural effusion of the primary form Direct extension into the ribs or [learningradiology.com]
Treatment
Common M. tuberculosis strains are sensitive towards several antibiotics. However, long-term treatments are necessary to eliminate these slowly metabolizing and growing pathogens. Compliance with the treatment regimen is of utmost importance and patients should generally take antibiotics for more than six weeks and in any case long after they are feeling well. Otherwise, relapses are likely and resistance development is possible. Patients have to be advised repeatedly on this risk and some physicians even prefer supervised drug intake. This directly observed therapy assures compliance and is presumably accompanied by shorter-term medication schemes and fewer relapses [14].
Since antibiotic resistance is a common feature of mycobacteria, treatment always includes the administration of at least two antibiotic drugs with different mechanism of action. A one-antibiotic regimen may not eliminate all pathogens and immunosuppressed patients may not be able to clear the remaining bacteria, which would lead to a relapse with mycobacteria resistant to that particular antibiotic.
In order to shorten the overall medication time, TB therapy is usually initialized with three or four different antibiotics. This approach drastically reduces bacterial load and increases chances of success.
The most commonly used antibiotics are isoniazid, rifampin, pyrazinamide, ethambutol and streptomycin [2]. These antibiotics are able to cure the vast majority of pulmonary TB cases (approximately 95%). Other drugs are only indicated if antibiotic resistance is detected or if there are other, absolute contraindications against the antibiotics of first choice.
Antibiotics against TB are usually taken all at once, once a day. There are formulations including more than one of these antibiotics, so the number of pills to be taken every day can be reduced. Dose schedules vary.
If pharmacological treatment does not suffice to treat pulmonary TB due to severe drug resistance, parts of the lung may be surgically removed. Surgery may also become necessary if other organs are involved and are severly compromised.
Prognosis
Provided that the patient is not infected with an extensively drug-resistant M. tuberculosis strain or a strain with multiple resistance, compliance with the antibiotic treatment regimen makes a complete cure very likely. Recurrence rates have been reported to range from 0 to 14%. In countries with a high prevalence of TB, recurrences might be confused with reinfections [9].
Prognosis worsens with age, immunosuppressive conditions, resistance to antibiotics and multiple organ infection. In a recent study, a limited innate immune response, an elevated respiratory rate at TB diagnosis and a decline in general health have been identified as poor prognostic markers [10].
Etiology
Saliva and mucus of a person affected by pulmonary TB does contain mycobacteria and is contagious. Microorganisms can be expelled while speaking, sneezing or coughing. These bacteria may be inhaled by another person, who will subsequently become infected themselves [3].
Once mycobacteria reach the alveoli of the as of yet unaffected person, alveolar macrophages take them up. The bacteria, however, are able to evade the host's defense mechanisms and survive within the macrophages' phagosome. If the immune system is able to withhold the infection, a granuloma may develop and the affected person may not even show any symptoms of TB. They are then merely considered infected with M. tuberculosis or as suffering from latent TB. Clinical tests for TB may produce positive results, but the patient is not able to transmit the disease. However, as soon as the person develops clinical symptoms, they are considered to suffer from TB.
In severe cases, mycobacteria may reach the lymphatic system and the bloodstream of the host and subsequently establish infections of other organs such as liver and spleen.
Any intrinsic or environmental factor weakening the immune system is considered a risk factor for TB [4]. Those factors comprise an HIV infection, diseases that weaken the immune system and alcoholism. Also, someone in prolonged, close contact to other people suffering from TB has a high risk of contracting TB, e.g. someone working in health care, someone living in or coming from a country with a high prevalence of the disease and someone living in poor or crowded conditions.
Epidemiology
TB is one of the major health concerns worldwide. Case numbers amount to several millions. In 2013, for instance, approximately 9 million new infections took place, mainly in Africa, South East Asia and the Western Pacific region. About 1.5 million people died from TB, a large share of whom were HIV positive.
But TB is by far no health problem restricted to developing countries. With regards to the United States, presumably almost 10 million people are infected with M. tuberculosis and nearly 10,000 new cases or 3 cases per 100,000 people have been reported in 2013 [5]. Of note, the case rate was significantly higher among people born abroad, particularly among those who immigrated from Asia [6].
Due to the immunosuppression associated with HIV infections, infections with M. tuberculosis display a particularly severe course in countries with a high HIV prevalence. Most infections with M. tuberculosis manifest as pulmonary TB.
Pathophysiology
TB is an infectious disease spread by droplet infection and M. tuberculosis has to be inhaled for bacteria to reach its host's alveoli [7]. Here, the pathogens are engulfed by alveolar macrophages and taken up into phagosomes. However, the phagosome of an infected cell does not fuse with a lysosome and therefore does not progress to the elimination of the bacteria. M. tuberculosis inhibits phagosome-lysosome-fusion and does also evade further host defense mechanisms. It does survive inside the phagosome, multiplies and eventually kills its host cell. Mycobacteria are then released and prompt a reaction of the immune system that may continue to eliminate the pathogen, to restrain the infection (patient develops latent TB) or completely fail to do so (patient develops pulmonary TB).
If the infection can be restrained but not eliminated, macrophages and T-helper cells form a caseating granuloma with a necrotic center. Mycobacteria can be found inside this granuloma which is delimited on the outside by a lymphocytic wall. The affected person does not transmit the disease, but rather suffers from latent TB. In this condition, radiographic images of the lungs do not show any alterations but the tuberculin skin test shows positive results [7][8].
Latent TB may be re-activated and progress to active pulmonary TB. The probability for this to occur is particularly high during the first two years after infection and increases after receiving immunosuppressive treatment with corticosteroids or similar drugs as well as after acquiring immunosuppressive diseases such as HIV.
Prevention
The BCG vaccine is an attenuated live vaccine extensively used to prevent TB. Vaccination with the BCG strain does not prevent pulmonary TB, but does significantly reduce TB meningitis and dissemination in children [15]. TB vaccinations are no longer routinely administered, but may be indicated in specific cases of high risk due to unavoidable exposure, particularly to resistant strains.
Physicians should be aware of the local regulations regarding suspected or confirmed cases of TB.
Summary
Pulmonary tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). It still represents one of the major concerns for health care authorities worldwide.
The disease is spread by droplet transmission. Mycobacteria reach the alveoli, are taken up by alveolar macrophages and frequently survive inside their host cells. The immune system may be able to limit the infection and to prevent any further spreading, in which case the affected person does not develop any symptoms and does not expel contagious material either. Mycobacteria are then preserved in granulomas. On the other hand, if the infection cannot be withheld or becomes re-activated, a primary pulmonary TB develops: the patient usually presents unspecific respiratory and general symptoms, whereby cough is the leading one. Here, saliva and sputum contain mycobacteria and are highly contagious. Most cases of primary pulmonary TB result from re-activated latent forms of the disease [1]. Reactivation may occur years after infection.
Although TB may spread to other organs, the vast majority of cases is limited to the lungs. A generalized immunosuppression may strongly increase the risk for re-activation and dissemination.
Besides the clinical examination, a chest X-ray, sputum culture, tuberculin skin test and interferon-γ release assay are valuable diagnostic measures [2].
If left untreated, about 50% of all patients suffering from pulmonary TB die. On the contrary, compliance with a long-term treatment regimen including several antibiotics is associated with a good prognosis.
Patient Information
Pulmonary tuberculosis (TB) is an infectious disease transmitted from man to man by droplet infection, i.e. by saliva and sputum. It mainly compromises the lungs but can spread to other organs.
Causes
Pulmonary TB is a bacterial infectious disease caused by M. tuberculosis. A person suffering from pulmonary TB harbors inflammatory spots in his or her lung and may expel bacteria when sneezing or coughing or even when speaking. If another person inhales these contagious droplets, they may contract TB.
Depending on the current state of the immune system and other factors, the body's immune defence may be able to eliminate or withhold the infection. If the infection is merely withheld, bacteria stay alive but inactive inside the patient's lung. In this condition, the person cannot transmit the disease. However, it is possible that the infection will be reactivated and in this case, the patient will expel contagious material. They may then infect other people.
Symptoms
Pulmonary TB is typically not accompanied by characteristic symptoms. Affected people may suffer from overall discomfort, loss of appetite, loss of body weight and cough. Fever may be present, but not necessarily. Some more severe cases are associated with difficulties to breathe, coughing up blood and chest pain.
Diagnosis
A clinical examination will be carried out and may reveal swollen and tender lymph nodes as well as unusual breath sounds.
Because pulmonary TB symptoms are not easily distinguished from those caused by other diseases, further diagnostic measures have to be undertaken in order to confirm the condition.
Those diagnostic measures may include imaging of the chest by X-rays or other techniques, a bronchoscopy (looking inside the bronchial tubes), a tuberculin skin test and an examination of the patient's sputum, among others.
Treatment
Pulmonary TB is a potentially curable disease. Therapy success depends largely upon the patient's compliance with long-term antibiotic therapy. Several antibiotics have to be administered at the same time because the pathogenic M. tuberculosis frequently shows resistance towards some antibiotics. Antibiotics have to be taken until long after symptoms have disappeared. Pulmonary TB is generally treated with isoniazid, rifampin, pyrazinamide, ethambutol and streptomycin. Provided that the treatment regimen is followed precisely, about 95% of all pulmonary TB cases are cured.
References
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- American Thoracic Society. Control of tuberculosis in the United States. Am Rev Respir Dis 1992; 146:1623-1632.
- Lienhardt C. From exposure to disease: the role of environmental factors in susceptibility to an development of tuberculosis. Epidemiol Rev. 2001; 23:288-301.
- Lin HH, Ezzati M, Murray M. Tobacco smoke, indoor air pollution and tuberculosis: a systematic review and meta-analysis. PLoS Med. 2007; 4:e20.
- Khan K, Wang J, Hu W, et al. Tuberculosis infection in the United States: national trends over three decades. Am J Respir Crit Care Med. 2008; 177:455-460.
- Alami NN, Yuen CM, Miramontes R, et al. Trends in tuberculosis - United States, 2013. MMWR Morb Mortal Wkly Rep. 2014; 63:229-233.
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- MacGregor RR. Tuberculosis: from history to current management. Semin Roentgenol 1993; 28:101-108.
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van Rie A, Warren R, Richardson M, et al. Exogenous reinfection as a cause of recurrent tuberculosis after curative treatment. N Engl J Med. 1999 Oct 14; 341(16):1174-9.
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Waitt CJ, Peter K Banda N, White SA, et al. Early deaths during tuberculosis treatment are associated with depressed innate responses, bacterial infection, and tuberculosis progression. J Infect Dis. 2011 Aug; 204(3):358-62.
- Bass JR, Jr, Farer LS, Hopewell PC, et al. Diagnostic standards and classification of tuberculosis. Am Rev Respir Dis 1990; 142:725-735.
- Ramakantan R, Bandekar VG, Gandhi MS, et al. Massive hemoptysis due to pulmonary tuberculosis: control with bronchial artery embolization. Radiology 1996; 200:691-694.
- Herold CD, Fitzgerald RL, Herold DA. Current techniques in mycobacterial detection and speciation. Crit Rev Clin Lab Sci 1996; 33:83-138.
- Bass JB, Jr, Farer LS, Hopewell PC, et al. Treatment of tuberculosis open link and tuberculosis infection in adults and children. Am J Respir Crit Care Med 1994; 149:1359-1374.
- Colditz GA, Brewer TF, Berkley CS, et al. Efficacy of BCG vaccine in the prevention of tuberculosis. JAMA. 1994; 271:698-702.