A CB‑NAAT blood test is a cartridge‑based nucleic acid amplification test that detects a pathogen’s DNA or RNA directly from a blood sample. It’s an automated, rapid molecular assay giving results in hours and can identify specific organisms and some resistance markers. It aids early diagnosis of bloodstream or systemic infections, though sensitivity can be reduced with low pathogen load and it doesn’t fully replace culture or clinical judgment.

Yes. TB PCR can detect Mycobacterium tuberculosis DNA in menstrual blood when genital or endometrial tuberculosis is present. Menstrual blood is a noninvasive sample and PCR gives rapid detection, but sensitivity and specificity vary and may be lower than endometrial biopsy or culture. PCR results should be interpreted with clinical findings and confirmed by additional tests (culture, histology, or repeat sampling).

CB-NAAT (Cartridge-Based NAAT) is recommended for people with TB symptoms (persistent cough, fever, night sweats, weight loss) and anyone suspected of pulmonary or extrapulmonary TB. It’s especially indicated for people living with HIV, children, contacts or previously treated patients when drug-resistant TB is suspected, smear-negative but clinically suspected cases, and patients with abnormal chest X-rays to detect TB and rifampicin resistance.

No — blood is not routinely sent for CBNAAT. The test is validated for sputum and many respiratory or selected extrapulmonary samples (e.g., lymph node aspirate, pus, CSF, pleural fluid, tissue). Mycobacterium tuberculosis DNA in blood is uncommon and CBNAAT sensitivity on blood is low, so blood-based CBNAAT is not recommended for routine TB diagnosis; use appropriate respiratory/tissue samples instead.

Nucleic acid test (NAAT) costs vary by country and provider. Many public-health programs offer NAATs free. In private labs, prices typically range from about $10–$30 in lower-cost settings to $50–$250 or more in higher-cost countries. Insurance, government coverage, urgent/same-day processing, or travel certification requirements can raise the final fee.

People with latent tuberculosis infection are usually asymptomatic — they have no cough, fever, night sweats, weight loss, or other signs of active disease. They often have a positive TB skin or blood test but normal chest X‑ray and negative sputum tests. Latent TB is not contagious, though it can reactivate later, so medical evaluation and preventive treatment may be recommended.