# Improving the efficiency of clinic-based active tuberculosis case finding: evaluation of point-of-care C-reactive protein-based triage testing in Vietnam.

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2020 · $181,824

## Abstract

PROJECT SUMMARY
Passive case finding – which relies on healthcare workers to determine which patients should be referred for
confirmatory TB testing – remains the predominant approach to TB case finding, resulting in missed or delayed
TB diagnosis and ongoing TB transmission within families and communities. In order to achieve the End TB
Strategy targets for a 95% reduction in TB deaths and a 90% reduction in TB incidence by 2035, immediate and
rapid scale-up of clinic-based active case finding (ACF; provider-initiated symptom screening, followed by Xpert
MTB/RIF [Xpert] confirmatory testing) is essential. However, the major barrier to ACF implementation is the low
specificity of symptom screening, which makes ACF unaffordable for most high burden countries because the
cost to test all symptomatic patients with Xpert testing would consume 20-80% of current TB spending. Thus,
there is an urgent need to identify an effective triage test than can limit the proportion of symptomatic patients
requiring Xpert testing to those with the highest likelihood of having active TB. The overall objective of this
application is to determine whether a triage testing strategy based on C-reactive protein (CRP) levels, measured
using a low cost ($2 per test) and rapid (results in 3 minutes) point-of-care (POC) assay could optimize selection
of patients for confirmatory TB testing. The central hypothesis is that a TB screening algorithm inclusive of POC
CRP triage testing will be more efficient than cough ≥2 weeks alone (currently recommended symptom screen)
and will thereby enable the efficient use of more sensitive TB screening strategies (e.g., any TB symptom, any
cough) to also improve ACF yield. The scientific premise for this hypothesis is based on our own work that
identified POC CRP as the first test to meet the minimum sensitivity (≥90%) and specificity (≥70%) targets
established by the WHO for an effective TB screening test among HIV-positive individuals. To test our
hypothesis, the study will enroll 1200 HIV-negative outpatients with any TB symptom (cough, fever, night sweats,
weight loss) from 4 clinics participating in the CDC-funded TB Trials Consortium (TBTC) Clinical Trials Unit
(CTU) in Hanoi, Vietnam. Aim 1 will determine the sensitivity, specificity and predictive values of POC CRP (cut-
point 10 mg/L) for culture-confirmed TB among patients who screen positive by 3 symptom-based screening
strategies: any TB symptom, any cough and cough ≥2 weeks (current recommendation). Aim 2 will perform
Xpert Ultra testing in all participants and will identify the optimal TB screening algorithm by comparing the
diagnostic yield (proportion of all TB cases detected by Xpert Ultra) and efficiency (number needed to test using
Xpert Ultra to detect one case of culture-confirmed TB) of 3 TB screening algorithms combining symptom
screening with POC CRP triage testing to 3 TB screening algorithms without POC CRP triage testing (symptom
screening alone), and to each oth...

## Key facts

- **NIH application ID:** 9956329
- **Project number:** 1R21AI151520-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Christina Yoon
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $181,824
- **Award type:** 1
- **Project period:** 2020-03-03 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9956329

## Citation

> US National Institutes of Health, RePORTER application 9956329, Improving the efficiency of clinic-based active tuberculosis case finding: evaluation of point-of-care C-reactive protein-based triage testing in Vietnam. (1R21AI151520-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9956329. Licensed CC0.

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