Feasibility and utility of a combined nasogastric-tube-and-string-test device for bacteriologic confirmation of pulmonary tuberculosis in young children

Nisreen Khambati; Rinn Song; Jonathan P Smith; Else Margreet Bijker; Kimberly McCarthy; Eleanor S Click; Walter Mchembere; Albert Okumu; Susan Musau; Elisha Okeyo; Carlos M Perez-Velez; Kevin Cain

doi:10.1016/j.diagmicrobio.2024.116302

Feasibility and utility of a combined nasogastric-tube-and-string-test device for bacteriologic confirmation of pulmonary tuberculosis in young children

Diagn Microbiol Infect Dis. 2024 Apr 18;109(3):116302. doi: 10.1016/j.diagmicrobio.2024.116302. Online ahead of print.

Authors

Affiliations

¹ Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK. Electronic address: nisreen.khambati@stcatz.ox.ac.uk.
² Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK; Division of Infectious Diseases, Boston Children's Hospital, Boston, MA USA; Department of Pediatrics, Harvard Medical School, Boston, MA USS.
³ Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention, Atlanta, Georgia, United States; Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut, United States.
⁴ Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, UK; Department of Pediatrics, Maastricht University Medical Center, MosaKids Children's Hospital, Maastricht, the Netherlands.
⁵ Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention, Atlanta, Georgia, United States.
⁶ Kenya Medical Research Institute - Center for Global Health Research, Kisumu, Kenya.
⁷ University of Arizona College of Medicine, Tucson, AZ USA.

PMID: 38657352
DOI: 10.1016/j.diagmicrobio.2024.116302

Abstract

For microbiological confirmation of pediatric pulmonary tuberculosis (PTB), gastric aspirates (GA) are often operationally unfeasible without hospitalization, and the encapsulated orogastric string test is not easily swallowed in young children. The Combined-NasoGastric-Tube-and-String-Test (CNGTST) enables dual collection of GA and string specimens. In a prospective cohort study in Kenya, we examined its feasibility in children under five with presumptive PTB and compared the bacteriological yield of string to GA. Paired GA and string samples were successfully collected in 95.6 % (281/294) of children. Mycobacterium tuberculosis was isolated from 7.0 % (38/541) of GA and 4.3 % (23/541) of string samples, diagnosing 8.2 % (23/281) of children using GA and 5.3 % (15/281) using string. The CNGTST was feasible in nearly all children. Yield from string was two-thirds that of GA despite a half-hour median dwelling time. In settings where the feasibility of hospitalisation for GA is uncertain, the string component can be used to confirm PTB.

Keywords: Diagnosis; Gastric aspirate; Microbiological confirmation; Pediatric tuberculosis; String.