Table 1.

Differences in the stages of tuberculosis

Early infection	Early primary progressive (active)	Late primary progressive (active)	Latent
-The host’s immune system combats the infection. -Progression of the disease takes place in the absence of signs or symptoms. -Patients could develop fever, paratracheal lymphadenopathy, or dyspnea. -The Infection may not progress to active stage but remain in a subclinical condition.	-The initial infection is not controlled by the host’s Immune system -The tissues become inflamed -Patient exhibits nonspecific signs or symptoms for example fever, loss of weight and fatigue. -Cough that develops in this stage is nonproductive. -Result of chest radiograph is normal and smear tests for sputum is negative for mycobacteria making diagnosis difficult.	-Cough in this stage is productive. -With the progress of the disease, signs and symptoms increase. -Patient suffers more weight loss, rales and anemia. -Result of chest radiograph is normal. -Cultures of sputum are used for diagnosis of the disease.	-The Mycobacteria continues to inhabit the host’s body. -Absence of signs or symptoms. -Patient does not feel sick. -Patient is at risk of reactivation of the disease. -Chest radiograph shows calcified granulomatous lesions which have become fibrotic. -There is likelihood of reappearance of the infection when risk factors present in the hosts cause immunosuppression.