Coronavirus disease 2019 (COVID-19), a highly infectious disease with the basic reproductive number (R0) of 5.7 (reported by the US Centers for Disease Control and Prevention), is caused by the most recently discovered coronavirus1 and was declared a global pandemic by the World Health Organization (WHO) on March 11, 20202. It poses a serious threat to human health worldwide, as well as substantial economic losses to all countries. As of 7 September 2020, 27,032,617 people have been infected by COVID-19 after testing, and 881,464 deaths have occurred, according to the statistics of the WHO3. The Wall Street banks have estimated that the COVID-19 pandemic may cause losses of $5.5 trillion to the global economy over the next 2 years4. The WHO recommends using real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) for laboratory confirmation of the COVID-19 virus in respiratory specimens obtained by the preferred method of nasopharyngeal swabs5. Laboratories performing diagnostic testing for COVID-19 should strictly comply with the WHO biosafety guidance for COVID-196. It is also necessary to follow the standard operating procedures (SOPs) for specimen collection, storage, packaging, and transport because the specimens should be regarded as potentially infectious, and the testing process can only be performed in a Biosafety Level 3 (BSL-3) laboratory7. Not all cities worldwide have adequate medical facilities to follow the WHO biosafety guidelines. According to an early report (Feb 17, 2020), the sensitivity of tests for the detection of COVID-19 using rRT-PCR analysis of nasopharyngeal swab specimens is around 30–60% due to irregularities during the collection and transportation of COVID-19 specimens8. Recent studies reported a higher sensitivity range from 71% (Feb 19, 2020) to 91% (Mar 27, 2020)9,10. A recent systematic review reported that the sensitivity of the PCR test for COVID-19 might be in the range of 71–98% (Apr 21, 2020), whereas the specificity of tests for the detection of COVID-19 using rRT-PCR analysis is about 95%11. Yang et al.8 discovered that although no viral ribonucleic acid (RNA) was detected by rRT-PCR in the first three or all nasopharyngeal swab specimens in mild cases, the patient was eventually diagnosed with COVID-19 (Feb 17, 2020). Therefore, the WHO has stated that one or more negative results do not rule out the possibility of COVID-19 infection12. Additional auxiliary tests with relatively higher sensitivity to COVID-19 are urgently required.