What Is the Predictive Value of a Single Nasopharyngeal SARS-CoV-2 PCR Swab Test in a Patient With COVID-Like Symptoms and/or Significant COVID-19 Exposure?

Abstract

Utilizing results of PCR testing and subsequent antibody titers, we report on the test characteristics of screening PCR test for Severe acute respiratory syndrome coronavirus-2 among hospital-workers. The PCR-test was found to be 87% sensitive, 97% specific, a positive predictive value of 0.98, and a negative predictive value of 0.80.

Increased complications in patients who test COVID-19 positive after elective surgery and implications for pre and postoperative screening

“…First, the SARS-CoV-2 RT-PCR may not detect the virus if tested too soon after exposure to COVID-19 when the viral replication phase of infection has not commenced. 19 Second, the quality of the nasal swab sample can affect the specificity of the test. Third, the patient may acquire an infection during their hospital stay or after returning home.…”

Discrepancies in the clinical and radiological profiles of COVID-19: A case-based discussion and review of literature

“…The usefulness of RT-PCR as a reference standard is limited due to its low sensitivity, sampling errors and the impact of timing of specimen collection[ 15 ]. RT-PCR testing from a single nasopharyngeal swab in a patient with COVID-19 like symptoms has sensitivity of 87%, specificity of 97%, positive predictive value (PPV) of 98% and negative predictive value (NPV) of 80%[ 16 ]. Because of the lower sensitivity, or when RT-PCR is unavailable, imaging tests have been used to aid in the diagnosis of COVID-19.…”

Implications of underrecognition of smell and taste as a symptom of COVID-19 infection

“…When anosmia is included in the list of symptoms, and symptomatic subjects are evaluated both by reverse transcriptase polymerase chain reaction (RT-PCR) and the antibody test, as many as 41.9% of those who test negative by RT-PCR subsequently test positive by the antibody test, 5 thereby implying a high false negative rate for RT-PCR. 5 In the latter study, characterization of symptomatic status included documentation of anosmia. 5 …”

“…A diagnostic trap which arises from underrecognition of anosmia, when it occurs in isolation, is that subjects who are erroneously perceived to be asymptomatic when they present with anosmia as a ‘stand-alone’ symptom may also test negative on the RT-PCR test in spite of the presence of COVID-19 infection. 5 In that context, they might become unrecognized asymptomatic spreaders, 6 undocumented and, therefore, unchecked.…”