Performance of Xpert Ultra nasopharyngeal swab for identification of tuberculosis deaths in northern Tanzania.

Abstract

Objective

Numerous tuberculosis (TB) deaths remain undetected in low-resource endemic settings. With autopsy-confirmed tuberculosis as our standard, we assessed the diagnostic performance of Xpert MTB/RIF Ultra (Ultra; Cepheid) on nasopharyngeal specimens collected postmortem.

Methods

From October 2016 through May 2019, we enrolled pediatric and adult medical deaths to a prospective autopsy study at two referral hospitals in northern Tanzania with next-of-kin authorization. We swabbed the posterior nasopharynx prior to autopsy and tested the samples later by Ultra. At autopsy we collected lung, liver, and, when possible, cerebrospinal fluid for mycobacterial culture and histopathology. Confirmed tuberculosis was defined as Mycobacterium tuberculosis complex recovery by culture with consistent tissue histopathology findings; decedents with only histopathology findings, including acid-fast staining or immunohistochemistry, were defined as probable tuberculosis.

Results

Of 205 decedents, 78 (38.0%) were female and median (range) age was 45 (0,96) years. Twenty-seven (13.2%) were found to have tuberculosis at autopsy, 22 (81.5%) confirmed and 5 (18.5%) probable. Ultra detected M. tuberculosis complex from the nasopharynx in 21 (77.8%) of 27 TB cases (sensitivity 70.4% [95% confidence interval {CI} 49.8-86.2%], specificity 98.9% [95% CI 96.0-99.9%]). Among confirmed TB, the sensitivity increased to 81.8% (95% CI 59.7-94.8%). Tuberculosis was not included as a death certificate diagnosis in 14 (66.7%) of the 21 MTBc detections by Ultra.

Discussion

Nasopharyngeal Ultra was highly specific for identifying in-hospital tuberculosis deaths, including unsuspected tuberculosis deaths. This approach may improve tuberculosis death enumeration in high-burden countries.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1016/j.cmi.2022.03.027

Publication Info

Costales, Cristina, John A Crump, Alex R Mremi, Patrick T Amsi, Nathaniel H Kalengo, Kajiru G Kilonzo, Grace Kinabo, Bingileki F Lwezaula, et al. (2022). Performance of Xpert Ultra nasopharyngeal swab for identification of tuberculosis deaths in northern Tanzania. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 28(8). pp. 1150.e1–1150.e6. 10.1016/j.cmi.2022.03.027 Retrieved from https://hdl.handle.net/10161/29837.

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Scholars@Duke

Crump

John Andrew Crump

Adjunct Professor in the Department of Medicine

I am an Adjunct Professor of Medicine, Pathology, and Global Health. My work with Duke University is primarily based in northern Tanzania where I am former Site Leader and current Principal Investigator on projects linked to Duke University’s collaborative research program at Kilimanjaro Christian Medical Centre. I oversee the design and implementation of research studies on infectious diseases, particularly febrile illness, invasive bacterial disease, zoonotic infections, and infectious diseases diagnostics. In addition, I am Professor of Medicine, Pathology, and Global Health at the University of Otago and a medical epidemiologist with the US Centers for Disease Control and Prevention (CDC). My CDC work focuses on non-malaria febrile illness.

Carugati

Manuela Carugati

Associate Professor of Medicine
Madut

Deng Madut

Assistant Professor of Medicine

I am an infectious diseases doctor who specializes in the care of patients with general infectious diseases, including persons living with HIV. My research is focused on improving the diagnosis and treatment of infectious diseases among populations living in low-resource settings.

Rubach

Matthew P. Rubach

Associate Professor of Medicine

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