Define the Ghon complex. What infection is it associated with?

The Ghon complex refers to a specific radiological and pathological finding associated with pulmonary tuberculosis. It consists of a calcified focus of infection typically located in the lung, along with an involved lymph node that has also undergone granulomatous changes as a response to the mycobacterial infection. This complex is indicative of primary tuberculosis and signifies that the immune system has attempted to control the tuberculosis infection, leading to encapsulation of the bacteria and subsequent calcification.

This finding is significant in the context of tuberculosis, as it helps to demonstrate the body’s response to the infection and can often be seen on imaging studies such as chest X-rays. Detection of the Ghon complex may be crucial in diagnosing and tracking the progression of tuberculosis in patients, particularly in those who may not present with acute symptoms.

This understanding of the Ghon complex and its association with tuberculosis is essential for healthcare providers diagnosing latent or active TB, as well as for public health initiatives targeting TB prevention and control.