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| Methodology | Pros | Cons |
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| Symptoms | No need for lab infrastructure, diagnostic value if appropriate risk stratification is applied | This criterion has been approved only in conjunction with the TST and suggestive chest radiography |
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| Traditional chest radiograph | The basic equipment is very common in hospitals and some research centers. | The images are not always clear and the lesions in children are often subjective |
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| Thorax CT scan | Enhanced visualization of small lesions not seen on chest radiograph. X-ray high-resolution computed tomography, it is the most sensitive tool currently available to detect hilar adenopathy and/or early cavitation can be used for follow-up | Costly; requires scanner which is not readily available in many settings |
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| Algorithms | They are very helpful and easy to use in countries with restricted technology | Is not commonly used due to lack of validation, it is based on responses of patients to which scores are given which are thought to be very subjective |
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| M. tuberculosis culture | Gold standard for definitive diagnosis of adult TB | Culture usually takes weeks (or four days in accelerated culture), low sensitivity (˂50% in gastric aspirate/sputum) |
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| Smear stain | Rapid | Very low sensitivity (˂50% in gastric aspirate/sputum), difficulty in obtaining sputum samples, and poor performance of smear microscopy |
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| Tuberculin skin test (TST) | Very common and cheap reagent, easy to use and to interpret the results | Inespecific, only indicates infection with a mycobacteria or prior BCG vaccination |
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| Polymerase Chain Reaction (PCR) | This is a rapid, sensitive, specific and affordable method | These tests are not performed correctly in all clinical laboratories. The cost involved, the need for thermocycler (or boiling pots at specific temperature), and scrupulous technique to avoid cross-contamination of specimens preclude the use of PCR techniques in many developing countries |
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| In-house nucleic acid amplification assays | Mean sensitivity of 60%, with a proper technique could be done efficiently | These assays are dependent of operator’s skill |
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| Adenosin deaminase | This method does not require sputum, only blood. Very high sensitivity and specificity | The report presents unclear case definition, exclusion of nontuberculous patients, and a relatively small TB patient population (20 with active TB) |
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| Serology and antigen detection | In this method, the sample is blood which is easier to obtain than sputum (in PTB). It is very rapid and does not require specimen from the site of disease | Sensitivity and specificity depend on the antigen used |
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| In vitro interferon-gamma (IFN-γ) released assays (IGRAs) | These methods can replace TST for detection of latent TB infection. Rapid test versions are inexpensive, and dozens of commercial kits are on the market; high specificity (98–100%) | The test may have impaired sensitivity for very young children, for whom it should not be used to exclude the presence of M. tuberculosis |
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| GeneXpert MTB/RIF system | This requires minimal manipulation of sample and operator training. It utilizes real-time PCR technology to both diagnose TB and detect rifampicin resistance. Results in ~105 min. | Only one report in a children population from South Africa. There is a need to validate in other populations |
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| Gas sensor array electronic nose (E-Nose) | High specificity | Without data in children populations |
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