key: cord-0815178-0bczgiyy
authors: Yamaniha, Kazutaka; Kinjo, Takeshi; Akamine, Morikazu; Setoguchi, Michika; Tateyama, Masao; Fujita, Jiro
title: False-positive for SARS-CoV-2 antigen test in a man with acute HIV infection
date: 2021-04-15
journal: J Infect Chemother
DOI: 10.1016/j.jiac.2021.04.011
sha: 995b6f464fde6ea1923cbc78fb6891dad8236400
doc_id: 815178
cord_uid: 0bczgiyy

Although rapid antigen tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is convenient, some articles have demonstrated their low sensitivity indicating false-negative results should always be considered. Here, we raise the issue of false-positive on rapid antigen tests for SARS-CoV-2 with the first case of acute HIV infection who repeatedly positive for the rapid antigen test. A 39-year-old man was admitted to our hospital complaining of high-grade fever, dry cough, general fatigue, and anorexia. The rapid antigen test performed on a nasopharyngeal swab sample was positive, therefore the patient was separated in an isolated room apart from the COVID-19 ward while awaiting the confirmatory RT-PCR result. However, the RT-PCR for SARS-CoV-2 performed on nasopharyngeal swabs was repeatedly negative (three times), while the antigen test was repeatedly positive (three times in total). This patient was eventually diagnosed with acute human immunodeficiency virus (HIV) infection based on a high titer of HIV-RNA and absence of plasma HIV-1/2 antibodies. Physicians should consider the possibility of false-positive results in addition to false-negative results when using a rapid antigen test for SARS-CoV-2, and keep in mind that nucleic acid amplification tests are needed to confirm the diagnosis.

Recent reports have shown the unreliability of rapid antigen tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to their low sensitivity [1] [2] . Scohy et al. [1] tested 148 nasopharyngeal swabs and reported that the overall sensitivity of the rapid antigen test (COVID-19 Ag Respi-Strip test, Coris BioConcept, Gembloux, Belgium) was 30.2% compared to a quantitative reverse transcription PCR (RT-qPCR) test. Another study of 160 SARS-CoV-2 positive respiratory samples confirmed by reverse transcription PCR (RT-PCR) showed that the sensitivity of the rapid antigen test (BIOCREDIT COVID-19 Ag, RapiGEN, Gyeonggi-do, South Korea) ranged from 11.1% to 45.7% [2] . These studies clearly indicate that false-negative results should always be considered when using rapid antigen tests. 

Low performance of rapid antigen detection test as frontline testing for COVID-19 diagnosis

Evaluation of rapid antigen test for detection of SARS-CoV-2 virus

Another false-positive problem for a SARS-CoV-2 antigen test in Japan

Pharmaceutical Safety Division, Ministry of Health, Labour, and Welfare, Approval of diagnostic test for SARS-CoV-2 infection

Correlation of nonspecific antiviral activity with the ability to isolate infectious HIV-1 from saliva

We thank Editage (www.editage.com) for English language editing.

None.

Written informed consent was obtained from the patient for the publication.

The authors declare no conflicts of interest.