Biology- Tuberculosis (SNAB)

Tuberculosis is a contagious disease caused by the bacterium, myobacterium tuberculosis.

it has been around for thousands of years and has been a major cause of death. it is estimated that around two billion people are infected around the world (this is nearly a third of the whole population!). there are around nine million new cases every year and around two of these die from the disease. however most of these people are healthy. the disease mainly infects the lungs.

there has been a decline in the amount of TB cases because of the improved living conditions and sanitation. also the introduction of antibiotics has been a great help.

Symptoms-
only 30% of the people in close proximity to TB will become infected, and only 5-10% of these will develop any symptoms. there are two phases of the disease.

Primary infection-
this is where the immune system responds, it can last for several months and the…