In-home TB Testing Using GeneXpert Edge is Acceptable, Feasible, and Improves the Proportion of Symptomatic Household Contacts Tested for TB: A Proof-of-Concept Study

Andrew Medina-Marino; Dana Bezuidenhout; Charl Bezuidenhout; Shelley N Facente; Bernard Fourie; Sanghyuk S Shin; Adam Penn-Nicholson; Grant Theron

doi:10.1093/ofid/ofae279

In-home TB Testing Using GeneXpert Edge is Acceptable, Feasible, and Improves the Proportion of Symptomatic Household Contacts Tested for TB: A Proof-of-Concept Study

Open Forum Infect Dis. 2024 May 13;11(6):ofae279. doi: 10.1093/ofid/ofae279. eCollection 2024 Jun.

Authors

Andrew Medina-Marino^{1

2}, Dana Bezuidenhout³, Charl Bezuidenhout⁴, Shelley N Facente⁵, Bernard Fourie⁶, Sanghyuk S Shin⁷, Adam Penn-Nicholson⁸, Grant Theron⁹

Affiliations

¹ Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa.
² Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
³ Department of Epidemiology, Mailman School of Public Health, Columbia University, New York City, New York, USA.
⁴ School of Public Health, Boston University, Boston, Massachusetts, USA.
⁵ School of Public Health, University of California Berkeley, Berkeley, California, USA.
⁶ Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
⁷ Sue & Bill Gross School of Nursing, University of California Irvine, Irvine, California, USA.
⁸ FIND, Geneva, Switzerland.
⁹ NRF-DSI Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Stellenbosch University, Cape Town, South Africa.

Abstract

Background: Household contact investigations are effective for finding tuberculosis (TB) cases but are hindered by low referral uptake for clinic-based evaluation and testing. We assessed the acceptability and feasibility of in-home testing of household contacts (HHC) using the GeneXpert Edge platform.

Methods: We conducted a 2-arm, randomized study in Eastern Cape, South Africa. HHCs were verbally assessed using the World Health Organization-recommended 4-symptom screen. Households with ≥1 eligible symptomatic contact were randomized. Intervention households received in-home GeneXpert MTB/RIF molecular testing. GeneXpert-positive HHCs were referred for clinic-based treatment. Standard-of-care households were referred for clinic-based sputum collection and testing. We defined acceptability as agreeing to in-home testing and feasibility as generation of valid Xpert MTB/RIF results. The proportion and timeliness of test results received was compared between groups.

Results: Eighty-four households were randomized (n = 42 per arm). Of 100 eligible HHCs identified, 98/100 (98%) provided consent. Of 51 HHCs allocated to the intervention arm, all accepted in-home testing; of those, 24/51 (47%) were sputum productive and 23/24 (96%) received their test results. Of 47 HCCs allocated to standard-of-care, 7 (15%) presented for clinic-based TB evaluation, 6/47 (13%) were tested, and 4/6 (67%) returned for their results. The median (interquartile range) number of days from screening to receiving test results was 0 (0) and 16.5 (11-15) in the intervention and standard-of-care arms, respectively.

Conclusions: In-home testing for TB was acceptable, feasible, and increased HHCs with a molecular test result. In-home testing mitigates a major limitation of household contact investigations (dependency on clinic-based referral), revealing new strategies for enhancing early case detection.

Keywords: South Africa; active case finding; geneXpert; point-of-care testing; tuberculosis.

Abstract

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