Laboratory diagnosis of COVID-19 in China: A review of challenging cases and analysis

Abstract

Since the initial emergence of coronavirus disease 2019 (COVID-19) in Wuhan, Hubei province, China, a rapid spread of the disease occurred around the world, rising to become an international global health concern at pandemic level. In the face of this medical challenge threatening humans, the development of rapid and accurate methods for early screening and diagnosis of COVID-19 became crucial to containing the emerging public health threat, and prevent further spread within the population. Despite the large number of COVID-19 confirmed cases in China, some problematic cases with inconsistent laboratory testing results, were reported. Specifically, a high false-negative rate of 41% on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection by real-time reverse transcription-polymerase chain reaction (qRT-PCR) assays was observed in China. Although serological testing has been applied worldwide as a complementary method to help identify SARS-CoV-2, several limitations on its use have been reported in China. Therefore, the use of both qRT-PCR and serological testing in the diagnosis of COVID-19 in China and elsewhere, presented considerable challenges, but when used in combination, can be valuable tools in the fight against COVID-19. In this review, we give an overview of the advantages and disadvantages of different molecular techniques for SARS-CoV-2 detection that are currently used in several labs, including qRT-PCR, gene sequencing, loop-mediated isothermal amplification (LAMP), nucleic acid mass spectrometry (MS), and gene editing technique based on clustered regularly interspaced short palindromic repeats (CRISPR/Cas13) system. Then we mainly review and analyze some causes of false-negative qRT-PCR results, and how to resolve some of the diagnostic dilemma.

Analytical and Clinical Performance of Droplet Digital PCR in the Detection and Quantification of SARS-CoV-2

“…The current diagnosis of COVID-19 depends on nucleic acid amplification tests, and recently, many new methods such as loop-mediated isothermal amplification or CRISPR-based assays were developed. The serologic tests using the antigen/antibody of SARS-CoV-2 was also introduced and used for specific purpose or limited circumstance [ 5 – 7 ]. In particular, reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR) to identify the target gene of SARS-CoV-2 is a common diagnostic method performed from the early stage of the pandemic in many clinical laboratories.…”

“…Conventionally, RT-qPCR is a validated, sensitive molecular diagnostic tool that is used to detect infectious pathogens. However, during massive testing for COVID-19, several studies discussed the concern of false-negative results using RT-qPCR [ 5 , 13 – 16 ]. Therefore, more sensitive and accurate diagnostic tools are required.…”

A Review on the epidemiology and characteristics of COVID-19

“…The common symptoms and demises are informed by China. From the entire figure of positive cases, 79,968 infected patients have been recognized in China [39]. It has been found that the clinical characteristics of 1,099 numbers of COVID-19 patients, where the median incubation period time was approximately 3 days, basically the range is 0-24 days, the average period from the development of the symptoms to death was approximately 14 days [40].…”

“…In the community, the main measure for interrupting the transmission of the disease is the isolation of the infected individuals. For example in China, the decision was taken by Chinese medical authorities to quarantine suspected individuals for 14 days and isolated infected people [39]. Till now there is doubt of the virus's origin some says it came from animals like a bat [73], others say it came from snakes [74], so it is necessary to immediately stop eating these animals and stop coming in close contact with these animal's fluid and or tissues.…”

“…oxygen supplier and mechanical ventilator), etc. In Wuhan city, Chinese authorities had taken lockdown measures seriously and strictly which stopped/slowed down the virus spreading [39,75]. Ways of travel showed be minimized except for compulsory medical care.…”