Cartridge-Based Nucleic Acid Amplification Test for the Diagnosis of Pulmonary Tuberculosis: correspondence

Dear Editor,

We would like to share ideas on the publication, “A comparative study of cartridge-based nucleic acid amplification test and Ziehl-Neelsen stain with culture on Lowenstein-Jensen media as the gold standard for the diagnosis of pulmonary tuberculosis.”^[1] Roy et al. concluded that “whereas culture remains the gold standard for the diagnosis of tuberculosis (TB), CBNAAT has taken over the domain of diagnosis owing to its high sensitivity and rapid turnover time.”^[1] We agree that the new alternative technique might be useful for diagnosing TB. Previous reports also showed that the new technique might be superior for diagnosis.^[2–4] However, there are some issues for further studies. First, the cost-effectiveness of the new alternative technique should be assessed similar to Table 1. For a setting with limited resources, cost-effectiveness is an important issue. Second, the new system might be based on a more complex tool. It might require a medical technologist for quality control of analysis. It is questionable whether classical staining is still more functional in rural fieldwork. Finally, it should note that the new technique has a specificity of about 90% compared to culture.^[3] Hence, there is still a chance of nondiagnosis, which might lead to difficulty in disease control.