Tuberclosis is one of the most infectious and ancient disease. it is caused by bacteria mycobacterium tuberculosis, but very few people have risk of its reoccurrence round 5-10%.one third of the population is infected with this deadly disease and comes next to HIV. When active tuberculosis develops, disease localization, severity and outcome are highly variable. It may develop anywhere in the body but usually presents as pulmonary infection ,ranging from mild infection to chronic, cavitary and severely destructive disease. According to world health organization (WHO),TB is a worldwide pandemic. The different manifestation of infection with M.tuberclosis reflect the balance between the bacillus and host defence system. However one should be were that dissecting innate and acquired host responses are complementary and synergistic.
Shagufta Taqvi, Samra Jamal