Tuberculosis (TB) is an infectious disease because it spreads through tiny droplets when released through coughs and sneezes. TB is caused by mycobacterium tuberculosis, a human pathogen with a significant global impact. Mycobacterium Bovis is a cattle pathogen that causes bovine tuberculosis when humans consume contaminated food or milk (Moule & Cirillo, 2020). Mycobacterium tuberculosis is transmitted when an individual with pulmonary TB expels drops into the air, commonly through coughing or sneezing, which susceptible individual breathes. There are three possible results when a person inhales mycobacterium. Since it is a slow-growing bacteria, the host’s immune system can eradicate it or remain in a dormant state called latent TB infection. The third option is that the latent TB infection can become active immediately or decades later, depending on the immune system, leading to extrapulmonary TB (Moule & Cirillo, 2020). For instance, people with HIV/AIDS and diabetes have a high chance of the bacteria becoming active immediately because of the weakened immune system.
The lifecycle of TB begins with the inhalation of infected air, where the pathogens are isolated in the tubercle. Macrophages ingest the tubercle bacilli that manage to reach the lungs’ alveoli, but some survive (Upadhyay et al., 2018). The protection mechanisms in the body lead to inflammation as enzymes and cytokines are released to deal with the bacteria. The symptoms might manifest after a few weeks, and the disease might be diagnosed at this stage. The common symptoms of pulmonary TB include chronic coughing, which sometimes has blood in the sputum, fever, fatigue, inadvertent weight loss, and night sweats (Moule & Cirillo, 2020). It mainly affects the lungs, but it can escape into extrapulmonary sites such as the central nervous system, lymph nodes, and bones. Streptomycin was the first effective antibiotic still in use today, and the other is bacilli Calmette-Guerin (BCG), the vaccine for TB (Barberis et al., 2017). TB is prevalent and affects many people around the world annually.
References
Barberis, I., Bragazzi, N. L., Galluzzo, L., & Martini, M. (2017). The history of tuberculosis: From the first historical records to the isolation of Koch’s bacillus. Journal of Preventive Medicine and Hygiene, 58(1), 9-12. Web.
Moule, M. G., & Cirillo, J. D. (2020). Mycobacterium tuberculosis dissemination plays a critical role in pathogenesis. Frontiers in Cellular and Infection Microbiology, 10(65), 1-12. Web.
Upadhyay, S., Mittal, E., & Philips, J. A. (2018). Tuberculosis and the art of macrophage manipulation. Pathogens and Disease, 76(4), 1-12. Web.