TB (Tuberculosis) EXAM COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+

TB (Tuberculosis) EXAM COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+ TB was shown to be contagious in... - Answer- 1865 The bacterium that causes TB was discovered in... - Answer- 1882 The first drug that could kill TB bacteria was discovered in... - Answer- 1943 What are the organisms that cause TB? - Answer- Mycobacterium tuberculosis Also, M. bovis, M. africanum, M. microti, and M. Canetti How is TB spread? - Answer- TB spreads person to person through the air (cough, sneeze, speak, sing- droplet nuclei) droplet nuclei may remain suspended in air for many hours depending on the environment The probability that TB will be transmitted depends on what four factors? - Answer- 1. Infectiousness of the TB patient 2. Environment in which the exposure occurred 3. Frequency and duration of the exposure 4. Susceptibility (immune status) of the exposed individual What is drug- resistant TB? - Answer- TB that is resistant to at least one anti-TB drug. Can be difficult to treat. What is the difference between primary and secondary drug resistance? - Answer- Primary: caused by person-to-person transmission of drug-resistant organisms. Secondary: develops during TB treatment where either the patient was not treated with the right TB drugs or the patient did not properly follow the prescribed treatment regimen. When a person inhales droplet nuclei containing M. tuberculosis, where do the droplet nuclei go? - Answer- Larger droplets become lodges in the upper respiratory tract where the infection is unlikely to develop. May also reach small alveoli where infection can begin. After tubercle bacilli reach the alveoli, what happens? - Answer- Tubercle bacilli multiply in the alveoli and a small number may enter the lymph nodes and bloodstream and spread throughout the body. Bacilli may reach any part of the body, including areas where TB disease is most likely to develop. This may include the upper portion of the lungs, kidneys, brain, and bone. In 2 to 8 weeks the bodies immune system will intervene and hold the multiplication to prevent further spread to people. In people with LTBI, how does the immune system keep the tubercle bacilli under control? - Answer- The immune system produces special immune cells that surround the tubercle bacilli. These cells create a barrier shell that keep the bacilli contained and under control. How is LTBI detected? - Answer- Mantoux tuberculin skin test (TST) or interferon-gamma release assay (IGRA) Characteristics of LTBI: - Answer- 1. Tubercle bacilli are in the body, but under control. 2. TST and IGRA results are usually positive. 3. Usually the chest x-ray is normal. 4. Sputum smears, molecular tests, cultures are negative. 5. People with LTBI doe not have symptoms, are not infectious, are not counted as having a case of TB. Characteristics of TB disease: - Answer- 1. Tubercle bacillary are active in the body. 2. TST and IGRA results are usually positive. 3. Usually the chest x-ray is abnormal (if dz has hit the lungs). 4. Sputum smears, molecular tests, cultures or combo of these tests test positive for M. tuberculosis. 5. People with TB disease may have symptoms, may spread TB to others, are counted as having a case of TB. What happens if the immune system cannot keep the tubercle bacilli under control and the bacilli begin to multiply rapidly? - Answer- TB disease develops In the US, what percentage of people who have LTBI (but not HIV) usually develop TB disease over their lifetime? - Answer- 10% 5% in the first two years after infection 5% in their lifetime Conditions that may increase the risk that LTBI will progress to TB disease: - Answer- 1. infection with HIV 2. Hx of untreated or inadequately treated TB dz 3. Recent TB infection (past 2 years) 4. Abusing drugs, alcohol, cigarettes 5. Receiving immunosuppressive therapy like TNF antagonists, systemic corticosteroids ≥ 15mg of prednisone per day or immunosuppressive dugs after hogan transplant 6. Silicosis 7. DM 8. Chronic renal failure 9. Certain cancers like leukemia head, neck, lung 10. Certain intestinal conditions 11. Low body weight How does being infected with both M. tuberculosis and HIV affect the risk for TB disease? - Answer- Because of their weakened immune systems, people who are infected with both M. tuberculosis and HIV are more likely to develop TB disease and people who are infected only with M. tuberculosis. The risk of developing TB disease is 7% to 10% each year for people who are infected with both M. tuberculosis and HIV if HIV is untreated, where as the risk is 10% over a lifetime for people infected only with M. tuberculosis. How does an HIV positive patient get TB disease? - Answer- 1. Pt has LTBI and becomes infected with HIV then developed TB disease as the immune system weakens. 2. Pt has HIV infection and becomes infections with M. tuberculosis and rapidly develops TB disease. What part of the body is the most common site for TB disease? - Answer- Lungs (most common) Also: larynx, lymph nodes, pleura, brain, kidneys, bones, joints What is the classification system for TB based on and used for? - Answer- Based on the pathogenesis of TB. Heath departments and private health care providers use this system to describe patients. What happened to the number of TB cases in the US between ? - Answer- The number of TB cases reported decreased by an average of 6% a year. What happened to the number of TB cases in the US between ? - Answer- The number of new TB cases increased by 20%.