Rapid antigen test during a COVID-19 outbreak in a private hospital in Hong Kong.
Hong Kong Med J
; 28(4): 300-305, 2022 08.
Article
in English
| MEDLINE | ID: covidwho-1753980
ABSTRACT
INTRODUCTION:
In response to two nosocomial clusters of coronavirus disease 2019 (COVID-19) in our hospital, we adopted a series of strict infection control measures, including regular rapid antigen test (RAT) screening for high-risk patients, visitors, and healthcare workers. We evaluated the diagnostic performance of a locally developed RAT, the INDICAID COVID-19 Rapid Antigen Test (Phase Scientific, Hong Kong), using respiratory samples from both symptomatic and asymptomatic individuals.METHODS:
Real-time reverse-transcription polymerase chain reaction (rRT-PCR)-confirmed deep throat saliva (DTS) and pooled nasopharyngeal swab and throat swab (NPS/TS) samples collected from 1 November to 30 November 2020 were tested by INDICAID. Screening RATs were performed on asymptomatic healthcare workers during a 16-week period (1 December 2020 to 22 March 2021).RESULTS:
In total, 20 rRT-PCR-confirmed samples (16 DTS, four pooled NPS/TS) were available for RAT. Using the original sample, RAT results were positive in 17/20 samples, indicating 85% sensitivity (95% confidence interval [CI]=62.11%-96.79%). Negative RAT results were associated with higher cycle threshold (Ct) values. For samples with Ct values <25, the sensitivity was 100%. Of the 49 801 RATs collected from healthcare workers, 33 false positives and one rRT-PCR-confirmed case were detected. The overall specificity was 99.93% (95% CI=99.91%-99.95%). The positive and negative predictive values were 2.94% (95% CI=2.11%-4.09%) and 100%, respectively.CONCLUSION:
The INDICAID COVID-19 RAT demonstrated good sensitivity for specimens with high viral loads and satisfactory specificity for low-risk, asymptomatic healthcare workers.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
Type of study:
Diagnostic study
/
Experimental Studies
/
Observational study
/
Prognostic study
Limits:
Humans
Country/Region as subject:
Asia
Language:
English
Journal:
Hong Kong Med J
Journal subject:
Medicine
Year:
2022
Document Type:
Article
Affiliation country:
Hkmj219559
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