Tuberculosis (TB) Presentation PDF

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Uploaded by HighSpiritedBamboo

Iran University of Medical Sciences

2022

Dr. Mahdi Yadollahzadeh

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tuberculosis pulmonary disease infectious diseases

Summary

This presentation provides an overview of tuberculosis (TB), covering its etiology, epidemiology, transmission, infection, diagnosis, and treatment. The presentation also discusses various types of TB and their associated complications including tuberculosis of the upper airways, and further details on post-TB complications such as chronic pulmonary aspergillosis.

Full Transcript

Present by: Dr. Mahdi Yadollahzadeh. Pulmonologist (MD). Assistant professor. Department of Internal Medicine,  School of medicine,  TUBERCULOSIS Firoozgar General Hospital,  Iran University of Medica...

Present by: Dr. Mahdi Yadollahzadeh. Pulmonologist (MD). Assistant professor. Department of Internal Medicine,  School of medicine,  TUBERCULOSIS Firoozgar General Hospital,  Iran University of Medical Sciences. Ref: Harrison’s Principles of Internal Medicine, 21th edition, 2022. INTRODUCTION Mycobacterium tuberculosis complex. One of the oldest diseases known to affect humans. The top cause of infectious death worldwide.  ~70,000 years ago in Africa.  Affects the lungs, although other organs are involved in up to one-third of cases.  If properly treated, TB caused by drug-susceptible strains is curable in the vast majority of cases.  If untreated, the disease may be fatal within 5 years in 50–65% of cases.  Transmission: the airborne spread of droplet nuclei produced by patients with infectious pulmonary TB. ETIOLOGIC AGENT Family Mycobacteriaceae and the order Actinomycetales. Pathogenic species, M. tuberculosis complex, eight distinct subgroups, 1. M. tuberculosis: the most common and important. 2. M. africanum: in West, Central, and East Africa. 3. M. bovis & M. caprae : zoonotic members. (the bovine tubercle bacillus; characteristically: resistant to pyrazinamide, transmitted: unpasteurized milk). 4. M. pinnipedii: seals and sea lions in the Southern Hemisphere. 5. M. mungi: banded mongooses in southern Africa. 6. M. orygis: oryxes and other Bovidae in Africa. 7. M. microti: the “vole” bacillus, a less virulent organism. 8. M. canetti: rare, East African, unusual smooth colonies on solid media and is considered closely related to a supposed progenitor type. ETIOLOGIC AGENT  M. tuberculosis: a rod-shaped, non-spore-forming, thin aerobic, 0.5 μm by 3 μm, neutral on Gram’s staining.  AFB: once stained, the bacilli cannot be decolorized by acid alcohol.  Acid fastness: high content of mycolic acids, long-chain cross- linked fatty acids, and other cell wall lipids.  Lipids are linked to underlying arabinogalactan and peptidoglycan; very low permeability; reducing the effectiveness of antibiotics.  lipoarabinomannan: host interaction and facilitates the survival of M. tuberculosis within macrophages.  AFBs: Mycobacteria, Nocardia, Rhodococcus, Legionella micdadei, the protozoa Isospora and Cryptosporidium. ETIOLOGIC AGENT Acid-fast bacillus smear showing M. tuberculosis bacilli. EPIDEMIOLOGY WHO: 7.1 million new cases of TB (2019) were reported; but estimated 10 million new cases of TB occurred. 97% of cases were reported from low & middle-income countries. Eight countries accounted for 2/3 of all new cases: India, Indonesia, China, the Philippines, Pakistan, Nigeria, Bangladesh, and South Africa. 1980s-90s: cases of TB increased in industrialized countries.  Immigration from high incidence of TB.  The spread of the HIV epidemic.  Social problems (urban poverty, homelessness, drug abuse).  Dismantling of TB services. EPIDEMIOLOGY Estimated tuberculosis (TB) incidence rates (per 100,000 population) in EPIDEMIOLOGY Estimated tuberculosis (TB) mortality rates in HIV-negative people in 2018 EPIDEMIOLOGY TB incidence: stable or falling; 2000s 1.7%. RR-TB: rifampin- (also called rifampicin) resistant TB. MDR-TB (multidrug-resistant TB): Resistant at least to isoniazid and rifampin. XDR-TB (extensively drug-resistant TB): Resistance to powerful second-line anti-TB drugs (fluoroquinolones and at least one of the injectable drugs amikacin, kanamycin, and capreomycin). Only 44% of these cases were diagnosed because of a lack of culture and drug susceptibility testing (DST) capacity in many settings worldwide. EPIDEMIOLOGY WHO new definitions: (i) Pre-XDR-TB: That of MDR/RR-TB and also resistant to any fluoroquinolone. (ii) XDR-TB : That of M DR/RR-TB and also resist ant to any fluoroquinolone and at least one additional Group A drug including levofloxacin or moxifloxacin, bedaquiline, and linezolid.) ~ 6.2% of the MDR-TB  may be XDR-TB, but remain undiagnosed because of the lack of reliable methods for DST and limited capacity laboratory in low-income countries. A few cases were deemed resistant to all anti-TB drugs; however, information must be cautious because susceptibility testing for several second-line drugs is neither accurate nor reproducible. EXPOSURE TO INFECTION Droplet nuclei: the most commonly; aerosolized by coughing, sneezing, or speaking. Through the skin or the placenta: uncommon & of no significance. The tiny droplets dry rapidly; the smallest (90% trapped in the upper airways expelled by ciliated mucosal cells. Droplet inhaled 50% (usually ~4–6 g/dL), a normal to low glucose, a pH of ~7.3 (occasionally

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