Journal:2019 novel coronavirus disease (COVID-19): Paving the road for rapid detection and point-of-care diagnostics
|Full article title||2019 novel coronavirus disease (COVID-19): Paving the road for rapid detection and point-of-care diagnostics|
|Author(s)||Nguyen, Trieu; Bang, Dang Duong; Wolff, Anders|
|Author affiliation(s)||Technical University of Denmark|
|Primary contact||Email: awol at dtu dot dk|
|Volume and issue||11(3)|
|Distribution license||Creative Commons Attribution 4.0 International|
We believe a point-of-care (PoC) device for the rapid detection of the 2019 novel coronavirus (SARS-CoV-2) is crucial and urgently needed. With this perspective, we give suggestions regarding a potential candidate for the rapid detection of the coronavirus disease 2019 (COVID-19), as well as factors for the preparedness and response to the outbreak of COVID-19.
Keywords: COVID-19, Wuhan, 2019 novel coronavirus, point-of-care detection, SARS-CoV-2, loop-mediated isothermal amplification, LAMP assay, polymerase chain reaction, PCR
On January 30, 2020, the World Health Organization (WHO) declared a global public health emergency over the outbreak of a novel coronavirus, called the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (previously "2019 novel coronavirus" or "2019-nCoV"), which originated in Wuhan City, in the Hubei Province of China. On February 11, WHO officially named the disease the coronavirus disease 2019 (COVID-19). Human-to-human transmission (Figure 1) has been confirmed by WHO and by the Centers for Disease Control and Prevention (CDC) of the United States, with evidence of person-to-person transmission from three different cases outside China, namely in the U.S., Germany, and Vietnam.
COVID-19 has continuously spread to 104 countries; the number of confirmed infections reached 109,343 on March 9, 2020, and the death toll in China has overtaken the SARS epidemic of 2002–2003 and has risen to 3,100. To slow down the spread of COVID-19, at least 50 million people in China have been placed under lockdown. On March 8, 2020, Italy also undertook the same measures, with the northern part of the country getting placed under lockdown, affecting 16 million people. The reproduction number R0 (i.e., the average number of secondary cases generated by a typical infectious individual) is estimated to be 2.68, and the doubling time is estimated to be 6.4 days.
The difference in terminology between "coronavirus" and "SARS-Cov-2" is detailed in Table 1.
The need for a rapid detection method and portable detection devices
The manifestation of the COVID-19 infection is highly nonspecific, including respiratory symptoms, fever, cough, dyspnea, and viral pneumonia. Thus, diagnostic tests specific to this infection are urgently required to confirm suspected cases, screen patients, and conduct virus surveillance.
In this scenario, a point-of-care (PoC) device (i.e., a rapid, robust, and cost-efficient device that can be used onsite and in the field, and which does not necessarily require a trained technician to operate) is crucial for the detection of COVID-19. Figure 2 shows the dramatic impact of early detection of infectious diseases in controlling an outbreak.
Such a PoC device can be used in (but is not limited to) an emergency situation, such as the Diamond Princess cruise ship case. Recently, it was reported that the Diamond Princess cruise ship had been quarantined in Yokohama, Japan, due to a serious spreading of COVID-19 on the ship, with at least 454 infected cases out of 3,700 passengers and crew (reported by WHO, February 17, 2020). The detection of COVID-19 may not have been prompt enough as they did not have enough test kits to diagnose all the passengers on the ship in order to timely respond to the rapid spreading of the disease.
The current standard molecular technique that is now being used to detect SARS-CoV-2 is real-time reverse transcription polymerase chain reaction (rRT-PCR). This protocol has been documented and available online on the WHO website since January 17, 2020. The testing procedure includes: (i) specimen collection; (ii) packing (storage) and shipment of the clinical specimens; (iii) (good) communication with the laboratory and providing needed information; (iv) laboratory testing; and (v) reporting the results. This rRT-PCR technique requires sophisticated laboratory equipment that is often located at a central laboratory (Biosafety level 2 or above). Sample transportation is inevitable. As a consequence, the time required to obtain the results can be up to two or three days. In the case of a public health emergency such as the COVID-19 outbreak, this time-consuming process of sample testing is not only extremely disadvantageous, but also dangerous since the virus needs to be contained.
Another concern of PCR testing is that commercial PCR-based methods are expensive, depend upon technical expertise, and the presence of viral RNA or DNA does not always reflect acute disease. Furthermore, using PCR, codetection with other respiratory viruses is frequently encountered in coronaviruse (CoV) testing, and the contribution of positive CoV PCR results to disease severity is not always explicitly exhibited. Furthermore, as of February 2, 2020 in the United States, as mentioned in the Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons Under Investigation (PUIs) for 2019 Novel Coronavirus, diagnostic testing for COVID-19 can be conducted only at the CDC, though from February 4 onwards, COVID-19 tests can also be done at laboratories designated by the CDC. Likewise in China, where the outbreak is ongoing, samples had to be sent to Beijing for testing, as reported on January 31. On February 4, China’s own CDC deployed a mobile biosafety laboratory to Wuhan in the Hubei Province to assist with the response. On February 5, an emergency test laboratory (biosafety level 2) run by BGI Group (with global heartquarters in Shenzhen, China) was set up in Wuhan in the Hubei Province to assist the COVID-19 epidemic.
A potential candidate for rapid detection of SARS-CoV-2: Loop-mediated isothermal amplification (LAMP) assays in PoC devices
In order to overcome the current time-consuming and laborious detection technique using RT-PCR, an alternative molecular amplification technique should be deployed. Loop-mediated isothermal amplification (LAMP) reaction is a novel nucleic acid amplification technique that amplifies DNA with high specificity, efficiency, and rapidity under isothermal conditions. This method uses a set of four specially designed primers, in combination with a DNA polymerase with strand displacement activity to synthesize target DNA up to 109 copies in less than an hour at a constant temperature of 65 °C. The final products are stem-loop DNAs with multiple inverted repeats of the target, bearing structures with a cauliflower-like appearance. LAMP has high specificity and sensitivity and is simple to perform; hence, soon after its initial development, it became an enormously popular isothermal amplification method in molecular biology, with applications in pathogen detection. LAMP uses strand-displacement polymerases instead of heat denaturation to generate a single-stranded template. As such, it has the advantage of running at a constant temperature, simultaneously reducing the cumbersomeness of a thermocycler as well as the energy required. LAMP technology is proven to be more stable and more sensitive in detection compared to PCR. Other advantages of LAMP compared to those of PCR are shown in Table 2.
We believe that the LAMP assay could be a potential candidate for the point-of-care device application in the detection of COVID-19. The Veterinary Validation of Point-of-Care Diagnostic Instrument (VIVALDI) project is an example of using LAMP in a point-of-care device for the detection of a zoonotic virus causing respiratory symptoms (such as the strains responsible for Avian influenza). With PoC devices such as the VETPOD (Veterinary, Portable, Onsite Detection), which the VIVALDI project is validating, detection time can be less than one hour. Besides PoC devices using disposable polymer chips and LAMP assays, as in the VETPOD, a lateral flow strip (LFS) would also be a suitable candidate for the rapid and on-site detection of COVID-19. A device such as COVID-19 IgM/IgG Rapid Test of BioMedomics is a good example. The sensitivity of the COVID-19 IgM/IgG Rapid Test is 88.66%, which is expected to be lower than the sensitivity of tests based on LAMP-reaction assays (>95%). Therefore, a combination of LFS and LAMP into one device could be an excellent candidate for PoC testing of COVID-19.
Other important factors in fighting COVID-19
Furthermore, alongside detecting and containing the virus, for the sake of a public health response regarding the dynamics of the outbreak, the socio-economic impact of COVID-19 is equally in urgent need. WHO announced that to fight the further spread of COVID-19, the international community had launched a U.S. $675 million preparedness and response plan to run from February through April 2020. In 2003, the SARS-CoV virus pulled the world’s output down by $50 billion. The early estimation for the cost to the global economy as a result of the outbreak of COVID-19 is about $360 billion. This is because China’s GDP shares were approximately 17% globally as of 2019, which was about four times higher than in 2003, and the confirmed infected cases (at the time of doing the economic estimation, i.e., at the beginning of February 2020) are more than two times larger than the total of SARS. Given that the number of infected cases (109,343 confirmed cases) is currently approximately 14 times larger than SARS cases, and that the death toll due to COVID-19 has surpassed that of the SARS epidemic, the economic impact of COVID-19 might be much larger than $360 billion.
Furthermore, in order to win the battle against this outbreak, information on the epidemiological characteristics, such as the identification of the animal reservoirs (Figure 1) and the risk factor of the disease, is also essential. The intermediate host carrying the disease is important to identify not only for the current epidemic, but also to eliminate a future outbreak. Together with all the aforementioned factors, the race for a vaccination against COVID-19 is equally essential. Although at this stage there is no registered treatment or vaccine for COVID-19, Zhang has recently mentioned some potential interventions, such as nutritional interventions (Vitamin A, B, C, D, E, and other trace minerals such as zinc and iron). Due to the high percentage of identicality in the sequence (up to 82% of the genome structure) between SARS-COV-2 and the SARS-CoV virus, immuno-enhancers and other specific treatment that have been applied for SARS could also be considered for treatment of SARS-CoV-2.
Conceptualization, T.N.; writing—original draft preparation, T.N.; manuscript revision, T.N, D.D.B., and A.W.; funding acquisition, D.D.B., A.W. All authors have read and agreed to the published version of the manuscript.
This research was funded by the European Union’s Horizon 2020 research and innovation program, the CORONADX project, grant agreement No: 101003562, and the VIVALDI project, grant agreement No: 773422.
Conflicts of interest
The authors declare no conflict of interest.
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This presentation is faithful to the original, with only a few minor changes to presentation. In some cases important information was missing from the references, and that information was added. The original article referenced a generic situation report page from the WHO for the Diamond Princess infection numbers; the specific report (#28) is referenced for this version. Similarly, a more specific citation was used in this version for the mentioned VETPOD system. In a few places, "SARS-CoV-2" replaced "COVID-19" when the authors intended to reference the virus but referenced the disease.