1. Tuberculosis
Iran is considered a high-burden country for tuberculosis, with a
notable incidence rate. The endemicity of TB in this region increases
the pretest probability of the disease in patients presenting with
compatible symptoms and radiological findings (3). Sputum smear
microscopy and culture are commonly used for the diagnosis of pulmonary
TB. However, it’s essential to recognize the limitations of these tests
(5, 6).
Smear microscopy has a sensitivity ranging from 36.9% to 55.6% and
specificity of around 99%, while culture has higher sensitivity
(approximately 80-90%) but takes longer for results (7, 8).
Importantly, negative smear and culture results do not exclude the
diagnosis of TB, especially in cases of paucibacillary disease or
extrapulmonary involvement (8).