MPT64 antigen detection test improves diagnosis of pediatric extrapulmonary tuberculosis in Mbeya, Tanzania

• Published in: Scientific reports Vol. 11; no. 1; pp. 17540 - 11
• Main Authors: Grønningen, Erlend, Nanyaro, Marywinnie, Sviland, Lisbet, Ngadaya, Esther, Muller, William, Torres, Lisete, Mfinanga, Sayoki, Mustafa, Tehmina
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.09.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/1647/664/1257; 631/326/2521; 692/308/3187; 692/499; 692/699/255/1856; 692/700/139/422; Adenitis; Adolescent; Antigens; Antigens, Bacterial - metabolism; Bacterial Proteins - metabolism; Child; Child, Preschool; Diagnosis; Female; Humanities and Social Sciences; Humans; Immunologic Tests - methods; Infant; Infant, Newborn; Laboratory tests; Male; Malnutrition; Meningitis; multidisciplinary; Mycobacterium tuberculosis - isolation & purification; Mycobacterium tuberculosis - metabolism; Patients; Pediatrics; Peritonitis; Predictive Value of Tests; Prospective Studies; Science; Science (multidisciplinary); Sensitivity analysis; Tanzania - epidemiology; Tuberculosis; Tuberculosis - diagnosis; Tuberculosis - epidemiology; Tuberculosis - metabolism; Tuberculosis - microbiology; Tanzania
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-97010-2

Pediatric extrapulmonary tuberculosis (EPTB) is a diagnostic challenge. A new immunochemistry based MPT64 antigen detection test has shown improved sensitivity compared to current laboratory tests. The aim of this study was to implement and validate the test performance in a resource limited African setting. Presumptive pediatric (0–18 y) EPTB patients were prospectively enrolled at Mbeya Zonal Referral Hospital, and followed to the end of treatment or until a final diagnosis was reached. Specimens from suspected sites of infection were subject to routine diagnostics, GeneXpert MTB/RIF assay and the MPT64 test. The performance of the tests was assessed using mycobacterial culture as well as a composite reference standard. 30 patients were categorized as TB cases, 31 as non-TB cases and 2 were uncategorized. In the TB group, the three most common infections were adenitis (30%), peritonitis (30%) and meningitis (20%). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the MPT64 test was 92%, 88%, 87%, 92% and 90%, respectively. Mortality was equally high among TB/non-TB cases (23% vs 21%), and malnutrition was the main comorbidity among TB cases. The MPT64 test was implementable in the routine diagnostics in a low-resource setting and improved the diagnosis of pediatric EPTB.