Pulmonary Tuberculosis
Disease Details
Family Health Simplified
- Description
- Pulmonary tuberculosis is a contagious bacterial infection primarily affecting the lungs, caused by Mycobacterium tuberculosis and characterized by symptoms such as persistent cough, chest pain, and weight loss.
- Type
- Pulmonary tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis. It is not a genetically transmitted disease; instead, it is primarily transmitted through airborne particles when an infected person coughs, sneezes, or talks. However, susceptibility to the disease can be influenced by genetic factors, but this is not the same as direct genetic transmission.
- Signs And Symptoms
- Tuberculosis may infect any part of the body, but most commonly occurs in the lungs (known as pulmonary tuberculosis). Extrapulmonary TB occurs when tuberculosis develops outside of the lungs, although extrapulmonary TB may coexist with pulmonary TB.General signs and symptoms include fever, chills, night sweats, loss of appetite, weight loss, and fatigue. Significant nail clubbing may also occur.
- Prognosis
- Progression from TB infection to overt TB disease occurs when the bacilli overcome the immune system defenses and begin to multiply. In primary TB disease (some 1–5% of cases), this occurs soon after the initial infection. However, in the majority of cases, a latent infection occurs with no obvious symptoms. These dormant bacilli produce active tuberculosis in 5–10% of these latent cases, often many years after infection.The risk of reactivation increases with immunosuppression, such as that caused by infection with HIV. In people coinfected with M. tuberculosis and HIV, the risk of reactivation increases to 10% per year. Studies using DNA fingerprinting of M. tuberculosis strains have shown reinfection contributes more substantially to recurrent TB than previously thought, with estimates that it might account for more than 50% of reactivated cases in areas where TB is common. The chance of death from a case of tuberculosis is about 4% as of 2008, down from 8% in 1995.In people with smear-positive pulmonary TB (without HIV co-infection), after 5 years without treatment, 50-60% die while 20-25% achieve spontaneous resolution (cure). TB is almost always fatal in those with untreated HIV co-infection and death rates are increased even with antiretroviral treatment of HIV.
- Onset
- The onset of pulmonary tuberculosis (TB) is typically insidious, meaning it develops gradually over time. Initial symptoms can be mild and may include a persistent cough, fatigue, weight loss, night sweats, and low-grade fever. These symptoms can slowly worsen over several weeks to months before more severe manifestations of the disease become apparent.
- Prevalence
- Prevalence refers to the total number of existing cases of a disease in a population at a given time. For pulmonary tuberculosis, prevalence varies widely by region, with higher rates typically seen in low- and middle-income countries. Specific numbers may change over time, so it's important to consult the latest reports from organizations like the World Health Organization (WHO) for the most current data.
- Epidemiology
- Roughly one-quarter of the world's population has been infected with M. tuberculosis, with new infections occurring in about 1% of the population each year. However, most infections with M. tuberculosis do not cause disease, and 90–95% of infections remain asymptomatic. In 2012, an estimated 8.6 million chronic cases were active. In 2010, 8.8 million new cases of tuberculosis were diagnosed, and 1.20–1.45 million deaths occurred (most of these occurring in developing countries). Of these, about 0.35 million occur in those also infected with HIV. In 2018, tuberculosis was the leading cause of death worldwide from a single infectious agent. The total number of tuberculosis cases has been decreasing since 2005, while new cases have decreased since 2002.Tuberculosis incidence is seasonal, with peaks occurring every spring and summer. The reasons for this are unclear, but may be related to vitamin D deficiency during the winter. There are also studies linking tuberculosis to different weather conditions like low temperature, low humidity and low rainfall. It has been suggested that tuberculosis incidence rates may be connected to climate change.
- Intractability
- Pulmonary tuberculosis is not inherently intractable. It can often be effectively treated with a prescribed course of antibiotics, typically including isoniazid, rifampin, ethambutol, and pyrazinamide. Treatment usually lasts for six to nine months. However, in some cases, the disease may become more difficult to treat due to drug-resistant strains of Mycobacterium tuberculosis, referred to as multidrug-resistant (MDR-TB) or extensively drug-resistant tuberculosis (XDR-TB). These forms of the disease are more challenging to manage and require longer and more complex treatment regimens.
- Disease Severity
- Pulmonary tuberculosis (TB) can range in severity depending on several factors, including the patient’s overall health and the timeliness of diagnosis and treatment. In general, it can cause severe respiratory issues, significant lung damage, and in some cases, may become life-threatening if not treated properly. The lack of proper treatment can also lead to complications such as spreading to other parts of the body. Early intervention and appropriate antibiotic therapy are crucial in managing the disease and mitigating its severity.
- Healthcare Professionals
- Disease Ontology ID - DOID:2957
- Pathophysiology
- Pulmonary tuberculosis is caused by the bacterium Mycobacterium tuberculosis. The pathophysiology involves the bacterium entering the lungs, typically via inhalation of respiratory droplets. Once inside, the bacteria are engulfed by alveolar macrophages but can resist destruction and replicate within these immune cells. The immune response leads to the formation of granulomas, where the bacteria can remain dormant. When the host's immune system is compromised, the bacteria can reactivate, resulting in active disease characterized by lung tissue destruction and symptoms like a persistent cough, hemoptysis, and weight loss.
- Carrier Status
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Pulmonary tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis. A person infected with TB may be in a latent or active stage.
1. **Carrier Status**: In the context of TB, "carrier" often refers to latent TB infection, where the individual harbors the bacteria but does not show symptoms and is not contagious. Such individuals have a 5-10% lifetime risk of progressing to active TB disease, where they can spread the bacteria to others.
2. **Nan**: It appears there might be a typo or misunderstanding, as "nan" generally stands for "not a number" in computing. If you have another specific question or need clarification, please provide additional details. - Mechanism
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Pulmonary tuberculosis (TB) is primarily caused by the bacterium Mycobacterium tuberculosis. The mechanisms of its action and molecular mechanisms are complex and involve several key processes:
**Mechanism:**
1. **Inhalation and Infection**: Pulmonary TB begins when aerosolized droplets containing Mycobacterium tuberculosis are inhaled into the lungs. The bacteria are then engulfed by alveolar macrophages.
2. **Immune Response**: The infected macrophages present antigens to T cells, triggering an immune response. Infected macrophages release cytokines, including tumor necrosis factor (TNF) and interferon-gamma (IFN-γ), which recruit more immune cells to the site of infection.
3. **Granuloma Formation**: To contain the infection, the immune system forms granulomas—structured aggregates of immune cells including macrophages, T cells, and sometimes necrotic tissue. This granuloma encapsulates the bacteria, limiting their spread but not necessarily eradicating them.
**Molecular Mechanisms:**
1. **Phagocytosis and Survival Inside Macrophages**: M. tuberculosis is phagocytosed by macrophages through several receptors, including the mannose receptor and complement receptors. Inside the macrophage, it inhibits phagosome-lysosome fusion, allowing it to avoid destruction and persist within the host cell.
2. **Regulation of Cytokines**: M. tuberculosis alters the host immune response by modulating cytokine production. For example, it can decrease the production of IL-12 and increase IL-10 production, skewing the immune response in a way that benefits its survival.
3. **Virulence Factors**: Various genes and proteins help M. tuberculosis survive and replicate. These include:
- **ESX-1 secretion system**: Critical for the export of virulence factors that manipulate the host immune response.
- **Lipids and Glycolipids**: Components of the cell wall that protect the bacterium from hostile environments and contribute to immune evasion.
- **Proteins such as CFP-10/ESAT-6**: Involved in disrupting host cell membranes and modulating immune responses.
4. **Immune Evasion**: The bacteria can downregulate major histocompatibility complex (MHC) class II molecules on macrophages, thereby reducing antigen presentation to T cells and further dampening the immune response.
5. **Environmental Adaptation**: M. tuberculosis can adapt to various hostile conditions within the host by altering its metabolism and entering a dormant state in response to stresses like hypoxia or nutrient limitation. This dormancy contributes to the persistence and latency of the disease.
These mechanisms allow M. tuberculosis to persist within the host for long periods, potentially leading to latent infections that can reactivate later in life, particularly if the host's immune system becomes compromised. - Treatment
- Treatment of TB uses antibiotics to kill the bacteria. Effective TB treatment is difficult, due to the unusual structure and chemical composition of the mycobacterial cell wall, which hinders the entry of drugs and makes many antibiotics ineffective.Active TB is best treated with combinations of several antibiotics to reduce the risk of the bacteria developing antibiotic resistance. The routine use of rifabutin instead of rifampicin in HIV-positive people with tuberculosis is of unclear benefit as of 2007.Acetylsalicylic acid (aspirin) at a dose of 100 mg per day has been shown to improve clinical signs and symptoms, reduce cavitary lesions, lower inflammatory markers, and increase the rate of sputum-negative conversion in patients with pulmonary tuberculosis.
- Compassionate Use Treatment
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Compassionate use treatment for pulmonary tuberculosis (TB) generally involves accessing investigational drugs or therapies that are not yet widely available but may provide potential benefits for patients with limited options. These treatments are often used in cases of drug-resistant TB or when standard therapies have failed.
Off-label or experimental treatments for pulmonary TB can include:
1. **Linezolid**: Though primarily used for other bacterial infections, linezolid has shown effectiveness against multi-drug resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB).
2. **Bedaquiline**: Originally approved for MDR-TB, bedaquiline is also being explored in various combinations for broader TB treatment.
3. **Delamanid**: Used similarly to bedaquiline, delamanid is another drug for treating MDR-TB and its effectiveness is being studied in various regimens.
4. **Pretomanid**: Often used in combination with other drugs like bedaquiline and linezolid (BPaL regimen), it is gaining recognition for treating resistant forms of TB.
5. **Immune Modulators**: There is ongoing research on therapies that modulate the immune system, such as interferon-gamma and various cytokines, to enhance the body’s ability to fight TB.
6. **Repurposed Drugs**: Antibiotics like clofazimine and meropenem are being tested in combination regimens for TB, though not originally developed for this disease.
7. **Vaccines**: Experimental vaccines, like M72/AS01E, are under study for both prevention and potential therapeutic benefits in TB.
These treatments are typically considered when conventional therapies are ineffective or unavailable, and they are usually accessed through clinical trials or special compassionate use programs. - Lifestyle Recommendations
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**Lifestyle Recommendations for Pulmonary Tuberculosis:**
1. **Medication Adherence:** Strictly follow the prescribed medication regimen to ensure effective treatment and prevent drug resistance.
2. **Nutrition:** Maintain a balanced diet to strengthen the immune system. Include foods rich in proteins, vitamins, and minerals.
3. **Hydration:** Drink plenty of fluids to stay hydrated and support overall health.
4. **Rest:** Ensure adequate sleep and rest to help the body recover and fight the infection.
5. **Avoid Smoking and Alcohol:** Both can aggravate your condition and weaken your immune system.
6. **Infection Control:** Practice good hygiene—cover your mouth when coughing or sneezing, and dispose of tissues properly. Use masks if necessary to prevent spreading the disease to others.
7. **Regular Check-ups:** Attend scheduled medical appointments for monitoring progress and managing any side effects of treatment.
8. **Exercise:** Engage in moderate physical activity as tolerated to maintain overall fitness and lung function, but avoid strenuous activities if you feel unwell.
9. **Mental Health:** Seek support for mental well-being, as chronic illness can be mentally taxing. Consider counseling or support groups.
10. **Avoid Crowded Places:** Reduce exposure to crowded or poorly ventilated areas to prevent spreading the infection to others.
11. **Smoking Cessation:** If you smoke, seek help to quit, as smoking can worsen lung damage and overall health. - Medication
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For pulmonary tuberculosis, the primary medications used are:
1. **Isoniazid (INH)**
2. **Rifampicin (RIF)**
3. **Pyrazinamide (PZA)**
4. **Ethambutol (EMB)**
These drugs are typically given in combination for a period of 6-9 months to ensure the complete eradication of the Mycobacterium tuberculosis bacteria and to prevent the development of drug resistance. Treatment often starts with an intensive phase of 2 months, followed by a continuation phase. - Repurposable Drugs
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For pulmonary tuberculosis, repurposable drugs include:
1. Linezolid: Originally an antibiotic for Gram-positive infections.
2. Amoxicillin/clavulanate: Typically used for bacterial infections.
3. Metformin: Primarily used for Type 2 diabetes but shown to have immune-modulatory effects.
4. Statins: Usually for cholesterol management, they have potential anti-inflammatory properties.
These drugs are being studied for their potential benefits in treating tuberculosis beyond the standard anti-TB medications. - Metabolites
- Pulmonary tuberculosis is primarily associated with various metabolites, which include mycolic acids, lipoarabinomannan (LAM), and various glycolipids. These metabolites are linked to the Mycobacterium tuberculosis bacterium and its pathogenic mechanisms. They play roles in the bacteria's survival, virulence, and interaction with the host immune system.
- Nutraceuticals
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Nutraceuticals, foods or supplements that provide health benefits beyond basic nutrition, are being studied for their potential to support the treatment of pulmonary tuberculosis (TB). While specific nutraceuticals are not a substitute for standard TB treatments such as antibiotics, they may help improve overall health, boost the immune system, and aid in recovery:
1. **Vitamin D:** Essential for immune function, some studies suggest it may improve outcomes in TB patients when used with conventional therapy.
2. **Vitamin A:** Supports immune health and may help in the maintenance of mucosal surfaces, including the lungs.
3. **Zinc:** An important immune-modulating mineral, zinc deficiency is linked to increased susceptibility to infections like TB.
4. **Probiotics:** Can help restore gut flora disturbed by long-term antibiotic use, potentially benefiting overall immunity.
5. **Curcumin:** The active compound in turmeric, curcumin has anti-inflammatory properties that may support immune function.
Regarding nanotechnology (nan), it holds promise in developing more advanced and effective treatments for pulmonary tuberculosis:
1. **Drug Delivery Systems:** Nanoparticles can be used to deliver anti-TB drugs more effectively, targeting the infection site more efficiently and reducing side effects.
2. **Diagnostics:** Nanotechnology can enhance TB diagnostics through highly sensitive and rapid detection techniques.
3. **Vaccines:** Development of nanoparticle-based vaccine delivery systems aims to improve the effectiveness and longevity of TB vaccines.
4. **Therapeutic Agents:** Nanoparticles can be engineered to carry therapeutic agents that directly target Mycobacterium tuberculosis, the bacteria causing TB.
These emerging fields offer potential supplementary and future strategies to combat pulmonary tuberculosis, complementing standard medical treatments. - Peptides
- Pulmonary tuberculosis (TB) is caused by the bacterium *Mycobacterium tuberculosis*. Peptides, which are short chains of amino acids, play a significant role in the immune response against TB. Specific peptides derived from the TB bacteria can be used in diagnostic tests and vaccine development. They help in the activation of T-cells, which are crucial for mounting an immune response to fight the infection. There's also research into peptide-based therapies to improve TB treatment and diagnosis. The abbreviation "nan" in the context of TB is unclear and might need further specification to provide an accurate response.