Rapid Molecular Diagnosis of Pulmonary Tuberculosis in Children Using Nasopharyngeal Specimens

Abstract

Xpert testing on 2 NPAs is useful in children with suspected PTB, particularly in settings where IS and culture are not feasible.

Advances in the diagnosis of pneumonia in children

“…[82][83][84][85] Nasopharyngeal specimens may also be useful for the diagnosis of tuberculosis using the polymerase chain reaction (PCR) in children from whom it is not possible to obtain more representative lower respiratory tract samples. 86 Although sputum induction has been shown in many studies to be safe and to provide an effective specimen for microbiologic diagnosis of pulmonary tuberculosis in children of all ages, there are relatively few studies of its use in acute pneumonia. Recent data suggest that the diagnostic yield of induced sputum may be greater than for nasopharyngeal samples for specific organisms.…”

Diagnosing childhood pulmonary tuberculosis using a single sputum specimen on Xpert MTB/RIF at point of care

“…Although obtaining an induced sputum specimen is a simple and well-tolerated procedure, [14] it needs to be conducted by a trained healthcare worker. The capacity to perform such induction is limited [16] and its uptake has been slow. In SA, many healthcare facilities are not able to obtain respiratory specimens (gastric aspirates or sputum) from children and many centres/ clinics lack sputum induction facilities or trained healthcare workers to perform the procedure.…”

“…[12] The updated Cochrane review on Xpert's performance in adults showed a pooled sensitivity of 98% for smear-positive pulmonary TB and 79% for smear-negative TB. [12] In the paediatric population, [9,[13][14][15][16] where sensitivities ranging from 33.3% [14] to approximately 70% [15,17] in smear-negative, culture-positive paediatric patients are reported. Increased sensitivities of up to 75.9% could be achieved if two induced sputa were tested.…”

“…Increased sensitivities of up to 75.9% could be achieved if two induced sputa were tested. [14] Further studies are now concentrating on alternative specimen types such as NPAs, [16] gastric lavage aspirates, [18] bronchoalveolar lavage [19] and stool. [20,21] In all Xpert studies on paediatric populations, specimens underwent laboratory decontamination and concentration prior to Xpert testing.…”

Advances in tuberculosis 2011–2012

“…The availability of the Xpert MTB/Rif assay allows for rapid diagnosis including accurate detection of rifampicin resistance. Studies in children indicate that Xpert done on two induced sputum specimens detected approximately 75% of culture-confirmed cases with very high specificity 26 27. While two nasopharyngeal specimens provided a lower yield than induced sputum for culture confirmation, the yield from Xpert on two nasopharyngeal specimens was similar, detecting almost 70% of culture-confirmed cases 27.…”