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Tuberculosis (TB)
Published in Charles Theisler, Adjuvant Medical Care, 2023
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis bacteria. It is characterized by the growth of nodules (tubercles) in tissues, especially the lungs. Worldwide, TB is the second most common cause of death from infection, after HIV/ AIDS. The emergence of resistant strains of tuberculosis and an increase in immuno-suppressed patients are significant clinical concerns. The inability to control this infection stems from the fact that the vaccines and drugs that were once effective against TB are no longer as efficacious. This has led to a search for new antituberculous agents and adjuvant therapy.1
Non-erythematous lesions
Published in Richard Ashton, Barbara Leppard, Differential Diagnosis in Dermatology, 2021
Richard Ashton, Barbara Leppard
Leprosy is a chronic bacterial infection due to Mycobacterium leprae. It is spread by droplet infection and has a long incubation period (anything from 2 months to 40 years). It principally affects peripheral nerves and the skin. The clinical features are very variable depending on the patient's cell-mediated immunity to the leprosy bacillus.
Extrapulmonary Tuberculosis
Published in Lloyd N. Friedman, Martin Dedicoat, Peter D. O. Davies, Clinical Tuberculosis, 2020
Mycobacterium tuberculosis can infect and cause disease at any site in the body. When tuberculosis (TB) occurs outside of the lung parenchyma, it is referred to as extrapulmonary TB, and results from the spread of tubercle bacilli throughout the body during the initial tuberculous infection. Approximately 20% of HIV-uninfected patients with TB have an extrapulmonary form of disease only, although the frequency varies between geographic areas and different populations.1,2 HIV-infected patients may be more likely to have an extrapulmonary site of disease than HIV-uninfected persons, and the risk of extrapulmonary TB increases as the CD4 lymphocyte count decreases.3,4 The two most commonly involved extrapulmonary sites are peripheral lymph nodes and the pleura, but any site or organ can be involved.5,6 Other common sites for extrapulmonary TB are those in well-vascularized areas such as the kidney, the meninges, the spine, and the growing ends of long bones.
The Relationship between COVID-19 Severity and Bacillus Calmette-Guérin (BCG)/ Mycobacterium tuberculosis exposure history in healthcare workers: a multi-center study
Published in Pathogens and Global Health, 2021
Serife Torun, Sevket Ozkaya, Nazan Şen, Fikret Kanat, Irem Karaman, Sebnem Yosunkaya, Ozlem Sengoren Dikis, Ali Asan, Selma Aydogan Eroglu, Sefa Semih Atal, Omer Ayten, Nimet Aksel, Hilal Ermiş, Neslihan Özçelik, Meryem Demirelli, Iskender Kara, Sua Sümer, Kamile Marakoğlu, Fatih Üzer, Yasin Uyar, Tuba Çiçek, Zuhal E Ünsal, Husamettin Vatansev, Berna Botan Yildirim, Tuba Kuruoğlu, Aynur Atilla, Yasemin Ersoy, Bahar Kandemir, Yasemin Durduran, Fatma Goksin Cihan, Nur Demirbaş, Fatma Yıldırım, Dursun Tatar, M Sule Akcay
Increased exposure to an infectious tuberculosis patient might develop neither active infection nor latent tuberculosis infection, also known as early clearance (resistance to infection by innate protection). Several immune mechanisms that functionally reprogram innate immunity such as unconventional T-cell responses, higher levels of T helper type 17 cytokines which are involved in the orchestration of neutrophil responses have been implicated in the early clearers [19]. Kooken et al.suggested that trained immunity can be responsible for eliminating the mycobacteria and inducing early clearance. Likewise, we hypothesized that different parameters that increase the exposure to M. tuberculosis bacillus such as presence of tuberculosis unit in the hospital, direct care and contact to infectious tuberculosis patients might have an impact on functional programming of innate immunity into trained immunity through early clearance mechanisms.
Integrating childhood TB: applying the care delivery value chain to improve pediatric HIV/TB services in Togo, West Africa
Published in AIDS Care, 2020
Melanie Dubois, Elissa Z. Faro, Diana S. Lee, Venance Katin, Komlan Kenkou, Kevin P. Fiori
Pediatric TB has historically been neglected from a public health standpoint for various reasons. One reason is that children are less contagious than adults with regards to disease transmission; this is largely due to the paucibacillary nature of childhood TB, as there is less bacteria in the sputum to spread to others (Starke, 2003). However, children have a significant burden of disease and different disease presentation compared to adults, as young children are more prone to extra-pulmonary and life-threatening cases of TB (Starke, 2003). Pediatric TB is also particularly challenging to diagnose as it is difficult to detect bacteria in sputum, often leading to delay in diagnosis or failure to diagnose. This failure in diagnosis is concerning, as it suggests an unrecognized global burden of childhood morbidity and mortality due to undiagnosed tuberculosis (Jenkins, 2017). Sputum smear microscopy is often the only diagnostic test available in many settings worldwide, but positive findings are noted for <10–15% of children with probable TB (Marais, 2007). Other diagnostic modalities, including gastric aspirates and induced sputum samples, are increasingly being used in children to improve detection of TB, particularly for children under age five. Mycobacterial culture remains the most definitive diagnostic test, but is not available in all settings (Ballif, 2015). In addition to these microbiological tests, contact tracing is particularly important for pediatric TB, as often pediatric cases can be connected to a recent exposure to an adult case of TB (Starke, 2003).
Inhalable dry powders of rifampicin highlighting potential and drawbacks in formulation development for experimental tuberculosis aerosol therapy
Published in Expert Opinion on Drug Delivery, 2020
Kai Berkenfeld, Jason T. McConville, Alf Lamprecht
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. M. tuberculosis is gram-negative bacterial species of the ubiquitous mycobacteriaceae family, showing slow growth (generation time is typically about 24 h), complex cell envelopes, and intracellular pathogenesis. Depending on the patient’s immune status, it may remain dormant for several years, which leads to delayed development of clinical symptoms [1]. The main site of infection is the lungs, though infections can secondarily spread to other organs (e.g. liver), and eventually generalize. Characteristic symptoms after lung infection, which typically occurs after exposition to bacteria conveying aerosols, include cough, fever, and hemoptysis, as well as anorexia and weight loss [2]. In 2018, approximately 10 million cases of TB were registered, making it the ninth leading cause of death globally and the leading cause of death from a single infectious agent [3]. Standard therapies of drug-susceptible strains include administration of four first-line antibiotics, i.e. rifampicin (rifampin, RIF), isoniazid (INH), ethambutol, and pyrazinamide over a period of at least 26 weeks [4].