Tuberculosis or head trauma. Introduction Print sectionTuberculosis (TB), a chronic or acute bacterial infection that mainly attacks the lungs, but can also affect the kidneys, bones, lymph nodes and brain. The disease is caused by Mycobacterium tuberculosis, a rod-shaped bacterium. Symptoms of tuberculosis include cough, chest pain, shortness of breath, loss of appetite, weight loss, fever, chills, and fatigue. Children and people with weakened immune systems are most susceptible to tuberculosis. Half of all untreated tuberculosis cases are fatal. In 1993, the World Health Organization (WHO) declared tuberculosis a global emergency, the first such designation ever made by that organization. According to the WHO, every second an individual is infected with tuberculosis and 8 million people contract the disease every year. Tuberculosis causes 2 million deaths per year. WHO predicts that between 2000 and 2020, nearly 1 billion people will be infected with the TB bacterium and 35 million people will die from the disease.II. Transmission and infection Tuberculosis is spread from person to person, usually through inhalation of air droplets carrying bacteria. When a person with tuberculosis coughs, sneezes or talks, small particles carrying two or three bacteria surrounded by a layer of moisture are released into the air. When another person inhales these particles, the bacteria can settle in that person's lungs and multiply. A less common route of transmission is through the skin. Pathologists and laboratory technicians who handle tuberculosis specimens can contract the disease through skin wounds. Tuberculosis has also been reported in people who have received tattoos and people who have been circumcised with unsterilized instruments. A person can be infected with tuberculosis bacteria and not develop the disease. Its immune system can completely destroy the bacteria. In fact, only 5-10% of people infected with tuberculosis actually get sick. If a person contracts the infection, the disease can develop in two stages: primary and secondary.A. Primary TB Print sectionIn primary tuberculosis, a person has been infected with TB bacteria but is often unaware of it, as this stage of the disease produces no obvious symptoms. Primary tuberculosis is not contagious in this early stage. Macrophages, immune cells that detect and destroy foreign bodies, ingest tuberculosis bacteria and deliver the... middle of paper......sizing additional vaccines. Tuberculosis Incidence, United States Many researchers attribute the sharp increase in the early 1990s to the spread of acquired immunodeficiency syndrome (AIDS). People with AIDS have weakened immune systems and are particularly susceptible to contagious diseases such as tuberculosis. Poorly controlled treatment of tuberculosis has also led to an increase in drug-resistant bacterial strains that cause tuberculosis, aiding the spread of the disease. Renewed emphasis on control and prevention has driven the incidence of tuberculosis to record levels. Tuberculosis in the Lungs Calcification of lung tissue, resulting from pulmonary tuberculosis, appears as yellow spots within the chest area of ​​this human x-ray. When airborne phlegm contaminated with the bacillus Mycobacterium tuberculosis is inhaled, nodular lesions, called tubercles, may form in the lungs and spread through the nearest lymph node. German scientist Robert Koch at work in his laboratory. Considered the founder of modern bacteriology 1905.