Tuberculosis (also known as TB or consumption) most commonly affects the lungs, although it can affect other body parts as well, such as the spine, brain, kidneys, lymph nodes, and even bones. The symptoms of the disease include weight loss, fatigue, fever, and feelings of general sickness and weakness all around. Depending on which part of the body is infected, there may also be persistent coughing, pain in the chest area, and coughing up blood in severe cases when the disease is in the lungs. In most cases, patients have latent TB infections, wherein the bacteria is inactive yet still alive, and these people may show no symptoms and are either undiagnosed or become diagnosed through other means.
As an airborne disease, tuberculosis is spread by bacteria travelling through the air. Namely, the disease is caused by Myobacterium tuberculosis. There are two different stages of TB, these being the TB infection and the TB disease. TB infection is where the immune system is unable to kill all of the TB bacteria, which remains inactive and becomes a latent TB infection. TB disease, on the other hand, occurs when the immune system is unable to fight off the TB bacteria. TB disease is infectious, and can be transferred between people through coughing, sneezing, or, very rarely, simply talking to one another in close proximity. However, it should be noted that, contrary to popular belief, TB is not spread through skin contact, sharing food and water, or kissing.
TB is considered to be among the top killers of infectious disease across the globe, killing approximately 2 million people annually. Despite this, with the development of treatments and more accurate diagnoses, the death rate has dropped by nearly half since the 1990s, which used to be death in one in every seven infected people in America and Europe. TB disease can spread from one infected body part to another. Depending on the site of infection, TB can kill through causing organ failure or respiratory failure. Despite this, the majority of people who are exposed to TB bacteria will not develop TB disease, and those with latent TB infections will not be sick or infectious to others.
Over 90% of TB-related deaths occur in low- to middle-income countries. Although TB can affect people of all genders and ages, it is most especially a leading cause of death for women aged 15 to 44 years. TB disease is especially lethal to people with impaired immune systems, such as patients with HIV/AIDS, those with recent organ transplants, people with certain cancers, and diabetics. Heavy smokers, people recently infected with TB (within 2 years), children under the age of 5 years infected with TB, and underweight people are also at higher risk of TB disease. In high income countries, those most at risk include the poor, the homeless, people in long term care or correctional facilities, and those who work with any of the above regularly. According to the World Health Organization, the country with the highest relative incidence of Tuberculosis is Swaziland, while the highest number of total, nominal incidences of TB are seen in India. Tuberculosis-related deaths are most commonly seen in Sub-Saharan Africa and South Asia.
Fortunately, TB disease can be prevented, treated, and cured. People with TB infections may be prescribed preventative treatments to keep their immune systems from weakening, and the infection from becoming active, whereas those with TB disease may be prescribed multiple antibiotics, which they are often required to take for up to a year to overcome the condition. It is crucial for patients to follow their medical regiment closely and finish all of their prescribed medication, because if they fail to take the drugs correctly or stop taking them, the TB bacteria may not be completely purged, and may come back stronger and even more resistant to the drugs. If this occurs, a new set of stronger drugs will have to be prescribed, which may cause more negative side effects than the standard treatment.