Point-of-care Ultrasound for Pulmonary and Extrapulmonary Tuberculosis in Children

To the Editors: We read with interest the letter by Buonsenso et al1 on their experience on lung ultrasound for pulmonary tuberculosis (PTB) in children in response to our study of point-of-care ultrasound (POCUS) in children. The authors indicate that POCUS of the lung is limited with regard to PTB. However, our article addresses POCUS for identification of concurrent extra-pulmonary tuberculosis (EPTB) in children with PTB2 but does not address lung ultrasound in children with PTB. Childhood PTB is difficult to diagnose because clinical presentation is nonspecific, and microbiologic confirmation is only achieved in a minority of children. Imaging therefore plays an important diagnostic role. However, current imaging tools are limited by sensitivity and specificity, as well as availability and/or feasibility in children. The standard radiologic study in childhood tuberculosis (TB) is chest radiograph, which can show parenchymal disease or pleural effusion but may not accurately detect mediastinal lymphadenopathy, has poor interreader agreement and may not be affordable in resource-poor, highly endemic settings.3–5 Computed tomography (CT) may certainly demonstrate lymphadenopathy more often and may be more accurate for parenchymal disease, but it is not the “standard” technique because of radiation exposure and cost. CT or magnetic resonance imaging is even less accessible and require sedation in young children. New imaging approaches are urgently needed to improve diagnosis of childhood TB, and ultrasound emerges as promising noninvasive and cheap point-of-care tool. Our work focused on POCUS for detection of EPTB because children are vulnerable to develop disseminated forms of TB. POCUS for EPTB was found to be valuable in the diagnostic work-up of HIV/TB coinfected adults who may also develop disseminated forms of TB.6–8 We showed that concurrent EPTB as detected by POCUS, that is, abdominal lymphadenopathy, pleural or pericardial effusion or splenic micro-abscesses, was prevalent in almost a third of children with PTB in our study in South Africa and that follow-up POCUS for EPTB was very useful for monitoring treatment response.2 In their letter, Buonsenso et al1 report lung ultrasound and CT findings from 9 pediatric TB cases from Sierra Leone (whether these cases had confirmed or unconfirmed PTB is not reported) and conclude that lung POCUS has limitations. We do not share their skepticism with regard to ultrasound for PTB, because in children PTB often presents with lung consolidation that may extend to the periphery and because ultrasound is better than chest radiograph in detecting small consolidation.9 Sabine Bélard, MDDepartment of Paediatrics and Child HealthRed Cross War Memorial Children’s Hospital, and MRC Unit on Child & Adolescent HealthUniversity of Cape TownCape Town, South AfricaCentre of Tropical Medicine and Travel MedicineAmsterdam Academic Medical CentersAmsterdam, The NetherlandsDepartment of Pediatric Pneumology and ImmunologyCharité-Universitätsmedizin BerlinHumboldt-Universität zu Berlin, and Berlin Institute of HealthBerlin Institute of Health (BIH)Berlin, Germany Charlotte C. Heuvelings, MDDepartment of Paediatrics and Child HealthRed Cross War Memorial Children’s Hospital, and MRC Unit on Child & Adolescent HealthUniversity of Cape TownCape Town, South AfricaCentre of Tropical Medicine and Travel Medicine, Amsterdam Academic MedicalCenters, location AMC, Amsterdam, The Netherlands Tom Heller, MDLighthouse ClinicLilongwe, Malawi Savvas Andronikou, PhDDepartment of Paediatrics and Child HealthRed Cross War Memorial Children’s Hospital, and MRC Unit on Child & Adolescent HealthUniversity of Cape TownCape Town, South AfricaDepartment of RadiologyChildren’s hospital of PhiladelphiaPhiladelphia, Pennsylvania Martin P. Grobusch, FRCPCentre of Tropical Medicine and Travel Medicine Amsterdam Academic Medical CentersAmsterdam, The Netherlands Heather J. Zar, PhDDepartment of Paediatrics and Child HealthRed Cross War Memorial Children’s Hospital, and MRC Unit on Child & Adolescent HealthUniversity of Cape TownCape Town, South Africa