Reducing Read Time of Point-of-Care Test Does Not Affect Detection of Hepatitis C Virus and Reduces Need for Reflex RNA.

BACKGROUND & AIMS: Global elimination of hepatitis C virus (HCV) will require increases in diagnosis. Point of care (POC) tests that detect antibodies against HCV can be useful for testing large and difficult to reach populations. The most accurate POC test requires a 20 min read time to identify antibody-positive samples. We investigated whether viremic patients could be identified using a shorter read time, to increase efficiency and reduce the need for reflex tests (a follow-up test for HCV RNA on the same specimen to confirm viremia). METHODS: Patients with past or current HCV infections provided samples at 2 clinics in Canada for evaluation by the OraQuick HCV Rapid antibody POC test. A community HCV-screening program in Madrid, Spain (real-world cohort) invited people to be tested for HCV with the same OraQuick test. Patients provided samples of whole blood, via finger prick. Fingerprick samples were tested immediately after collection. In the clinic cohort, photographs of the developing test were taken at 15 second intervals, and blinded readers recorded the time to positivity. In the real-world cohort, readers recorded the OraQuick result at 5 minutes, and each minute after, up to 10 minutes, and then again at 20 minutes; viremia was then evaluated using a POC HCV RNA test (GeneXpert HCV Viral Load Assay). Sera from viremic and non-viremic clinic patients were used to quantify antibody titers to investigate the relationship between the time of band appearance and antibody concentration. Fisher's exact test and exact logistic regression were used to determine factors associated with a positive result at 5 minutes. RESULTS: Blood from all viremic patients produced a positive result in the antibody POC test by 5 min. Median time to a positive result for 171 viremic patients was 2.6 min (range, 1.8-4.6 min), vs 4.1 min (range, 2.3-14.4 min) for 108 patients with resolved infection (P < .001). The 5-min threshold identified all viremic cases among 176 HCV antibody-positive patients in the real-world cohort, confirmed by testing for HCV RNA. In the pooled cohorts, antibody positivity at 5 min identified viremic patients with 100% sensitivity (95% CI, 98.4%-100%); the negative predictive value was 100% (95% CI, 94.9%-100%). The positive predictive value at 5 min was 62.0% (95% CI, 56.7%-67.0%) and therefore insufficient alone to detect viremia; an HCV RNA test would still be necessary to confirm active infection. CONCLUSIONS: The wait time for the OraQuick HCV Rapid antibody POC blood test can be reduced from 20 min to 5 min and continue to reliably identify patients with HCV infection. Shortening the test time could increase high-throughput screening, reduce loss to follow up, and reduce the need for reflex HCV RNA testing.

Birth cohort hepatitis C antibody prevalence in real-world screening settings in Ontario.

Background: Widespread screening and treatment of hepatitis C virus (HCV) is required to decrease late-stage liver disease and liver cancer. Clinical practice guidelines and Canadian Task Force on Preventative Health Care recommendations differ on the value of one-time birth cohort (1945-75) HCV screening in Canada. To assess the utility of this approach, we conducted a real-world analysis of HCV antibody (Ab) prevalence among birth cohort individuals seen in different clinical contexts. Methods: Cross-sectional study of individuals born between 1945 and 1975 who completed HCV Ab testing at multiple participating centres in Ontario, Canada between January 2016 and December 2020. Differences in prevalence were compared by year of birth, gender, and setting. Results: Among 16,672 birth cohort individuals tested, HCV Ab prevalence was 3.2%. Prevalence was higher among younger individuals which increased from 0.9% among those born between 1945 and 1956 to 4.6% among those born between 1966 and 1975. Prevalence was higher among males (4.4%) compared with females (2.0%) and differed by test site. In primary care, the prevalence was 0.5%, whereas the prevalence was highest among those tested at drug treatment centres (28.7%) and through community outreach (14.0%). Conclusions: HCV Ab prevalence remains high in the 1945-1975 birth cohort. These data highlight the need to re-evaluate existing Canadian Preventative Task Force recommendations, to consider incorporating one-time birth cohort and/or other population-based approaches to HCV screening into the clinical workflow as a preventative health measure, and to increase training among community providers to screen for and treat HCV.

Development and evaluation of screening dysphagia tools for observational studies and routine care in cancer patients.

BACKGROUND AND AIMS: Dysphagia can be associated with significant morbidity in cancer patients. We aimed to develop and evaluate dysphagia screener tools for use in observational studies (phase 1) and for routine symptom monitoring in clinical care (phase 2). METHODS: Various dysphagia or odynophagia screening questions, selected after an expert panel reviewed the content, criterion, and construct validity, were compared with either functional assessment of cancer therapy - esophageal cancer (FACT-E) Swallowing Index Cut-Off Values or to questions adapted from the Patient Reported Outcomes for Common Terminology Criteria for Adverse Events. Sensitivity, specificity, and patient acceptability were assessed. RESULTS: In Phase 1 (n = 178 esophageal cancer patients), the screening question "How are you currently eating?" had the highest sensitivities and specificities against various Swallowing Index Cut-Off Value cut-offs, with the best optimal cutoff associated with weight loss (80% sensitivity and 75% specificity). In phase 2 (255 head and neck, gastro-esophageal, and thoracic cancer patients), a single question screener ("Do you experience any difficulty or pain upon swallowing?") versus a Patient Reported Outcomes for Common Terminology Criteria for Adverse Events-like gold standard generated sensitivities between 86% and 94% and specificities between 93% and 100%. This screening question (+/- follow-up questions) had a median completion time of under 2 minutes, and >90% of patients were willing to complete the survey electronically, did not feel that survey made clinic visit more difficult, and did not find the questions upsetting or distressful. CONCLUSION: Our results demonstrate that these screener tools ("How are you currently eating?", "Do you experience any difficulty or pain upon swallowing?") can effectively screen dysphagia symptoms without increasing cancer outpatient clinic burden, both in observational studies and for routine clinical monitoring.