primary infection
Last reviewed 01/2018
Primary infection usually occurs in the lung resulting in a 'primary complex', which is a combination of:
- the primary (Ghon) focus of infection in the lung parenchyma, and
- caseous involvement of the regional lymph nodes, usually hilar nodes
If the initial site of infection is the ileum or the tonsil then the affected nodes will be the mesenteric or cervical.
In the majority of patients the primary complex heals and calcifies and the person becomes entirely asymptomatic but becomes sensitized to tuberculoprotein.
In a minority of patients the process of healing may not be complete and the patient may develop progressive pulmonary tuberculosis.