key: cord-0931654-qc3bkjyx
authors: Roy, Sharmili; Ramadoss, Archana
title: Updated insight into COVID-19 disease and health management to combat the pandemic
date: 2021-06-28
journal: Environmental and Health Management of Novel Coronavirus Disease (COVID-19 )
DOI: 10.1016/b978-0-323-85780-2.00017-2
sha: eb7b732880d0a7b3893dda626bee341f669bd679
doc_id: 931654
cord_uid: qc3bkjyx

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 disease in humans and is the responsible viral agent for the currently ongoing pandemic. Early cases of COVID-19 were reported from Wuhan, Hubei province of China, the likely birthplace of this outbreak. Currently, over 92 million people in the globe are actively battling this virus, and over 2 million individuals have already succumbed to the disease. The high human-to-human transmission capacity of the virus is among the primary causes for such a rapid global spread of COVID-19. In humans, it causes acute to severe respiratory distress in the form of pneumonia. The presentation of clinical features of the disease ranges from mild in healthy adults to severe among individuals with weakened or immunocompromised immune systems and the elderly. Thus, increasing patient cases of COVID-19 warrants a growing demand for medical attention that is eventually overburdening our health care systems. Rapid detection of COVID-19 in suspected individuals and isolation are among the crucial intervention norms in health management strategies to control the COVID-19 pandemic, in addition to strict observance of public hygienic practices such as reduced public gathering, use of facial masks, and practicing of social distancing. This chapter provides an overview of the epidemiology of COVID-19 and the current classical health management strategies and issues to tackle this pandemic. It particularly highlights the role of standard as well as novel biomolecular diagnostic techniques as a tool for successful implementation of such public safety measures issued by medical policy makers and the governing bodies.

prompt and swift surveillance of the disease progression, quarantine and social-distancing measures, closure of schools, and obligatory use of face masks. 12 Another example is that of Vietnam, home to 96 million people, which has surprised the world with less than 2000 COVID-19 cases in the country. 13 The success is primarily attributed to early risk assessment of the situation and placement of strict travel and border restrictions with foreign countries including quarantines apart from the standard health safety procedures. 14 Such successful examples have inspired many nations around the globe with hope that are actively battling the virus outbreak. However, attempts to contain the spread of the virus worldwide has not been uniform among all the nations globally since not all nations are in the same phase of infection, and other reasons, including less stringent public safety measures, delayed governmental policies, and/or even absence of prior experience with such a coronavirus epidemic. 15 For instance, in Italy, the country was taken by surprise when the initial outbreak of the virus was reported. The level of governmental unpreparedness, a decentralized policy of following different health safety measures in different regions of the country, in addition to not-so-sophisticated health care facilities caused significant economic and human loss in the country. 16 The world bank forecasts a great economic dip in the world economy since the world war era as the aftermath of this pandemic. 17 Given the deep impact of the pandemic as the world enters into a great socioeconomic dip, the importance of health management strategies cannot be stressed enough.

In humans, COVID-19 presents with clinical symptoms ranging from mild in healthy adults to severe in individuals with immune-compromised or weakened immune system and the elderly. 18e20 Some of the clinical symptoms include fever, sore throat, fatigue, loss of smell and sense of taste for milder cases, while acute-to-severe respiratory distress syndrome (ARDS) is among the major complications that require medical attention. 18 The rapid global spread of the disease warranting increased hospitalization of COVID-19 patients and constant monitoring of the disease progression in patients has pressured the scientific community worldwide. Scientists and health care professionals around the globe are working at record speeds to understand the origin and nature of SARS-CoV-2 to search for suitable novel technologies for rapid virus detection and vaccines to contain the spread of the virus. 21, 22 Currently, over 10 vaccines against SARS-CoV-2 are already available for public use, and many more are expected to be commercialized in the first quarter of 2021. 23e25 Albeit the success and enthusiasm regarding the commercial availability of COVID-19 vaccines, concerns such as efficiency of the vaccine over time and its effects on pregnant women are currently being evaluated. 26 Early detection of the virus and isolation and further quarantine are important steps of actions in the health care management strategies to control the COVID-19 pandemic. 27 , 28 Health care diagnostics and advances in biotechnology play an instrumental role in successful implementation of the health care management strategies. 29 Molecular biotechnological tools such polymerase chain reactions (PCRs) are the current global standard for detection of the virus in suspected individuals. Rapid detection of the virus in suspected individuals is of prime importance for efficient implementation of health management strategies aimed at containing the spread of the virus.

Keeping in mind all of the aforementioned facts, this chapter provides an overview of the epidemiology of coronavirus and the current classical health management strategies and issues to tackle this pandemic. The chapter particularly highlights the role of standard as well as novel biomolecular diagnostic techniques (with capacity to offer rapid and robust detection of SARS-CoV-2) as tools for successful implementation of such public safety measures issued by medical policy makers and governing authorities.

SARS-CoV-2 is classified as a member of the Coronaviridae family. 30 The detailed classification of the virus is shown in Fig. 1.1 . The newly identified SARS-CoV-2 is a bona fide human pathogen like some other famous members of this family, such as HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, SARS-CoV, and MERS-CoV. 31, 32 In the past, members of the betacoronavirus genus have caused human life-threatening respiratory diseases. 33 Examples include the SARS outbreak in 2003 and the MERS outbreak in 2012 with a mortality rate of 10% and 35%, respectively. 34, 35 Based on the mortality analyses of COVID-19 cases, the mortality rate is estimated to be between 0.4% and 9%. 36 The members of coronaviruses are a group of large enveloped viruses that carry positive-sense single-stranded RNA (þssRNA) as their genomes. 32, 37 They are known to infect a wide range of host organisms from chicken Updated insight into COVID-19 disease and health management to combat the pandemic to humans. 37 Although the origin of SARS-CoV-2 remains unclear, SARS-CoV-2 shares over w96% genetic similarity with RaTG13, a coronavirus strain originally thought to be found among the bats that are trapped in the Yunan caves of People's Republic of China (PRC). 38e41 Detailed structural studies using electron microscopy reveals that SARS-CoV-2 contains an icosahedral viral head structure and appears spherical with diameter in the range of w100e120 nm. 42, 43 The virus possesses numerous envelope proteins (E) such as spike (S), the transmembrane glycoprotein (M and E), and the nucleocapsid protein (N), as shown in Fig. 1.2 . 44 The uncanny resemblance of S protein on the virus envelope to that of the flares/corona of the sun or the crown of a queen, gives the virus its classical name of coronavirus. SARS-CoV-2 actively uses the S protein to engage with the host cell. 45 The S glycoprotein mediates viral anchoring on the host cell and fusion of the membranes for viral entry into the host cell. The virus uses human angiotensin converting enzyme 2 (ACE-2) to facilitate this viral entry. 46 Thus, current efforts to develop vaccines and antibodies to arrest the spread of the virus largely target the trimeric S protein. 43 Accumulation of point mutations in the S protein of the virus leading to the genomic evolution of SARS-CoV-2 has been elaborated in the following section.

SARS-CoV-2 carries þssRNA with a genomic size of w30 Kb, one of the largest genomic size among the known RNA viruses. 43 A key feature of this family of viruses is that they possess large open reading frame (ORF1a and ORF1b) that occupies nearly two-thirds of the genome (from the 3 0 proximal end of the genome) and encodes for nearly 16 nonstructural proteins while the rest of the genome (toward the 5 0 proximal end) encodes for all the known structural proteins of the virus. 47e49 SARS-CoV-2 appears to have a remarkable adaptation to its host organism. 50, 51 One of the 16 nonstructural proteins is nsp 13 that encodes for an exo-ribonuclease that provides a proofreading activity for the virus, thereby Updated insight into COVID-19 disease and health management to combat the pandemic efficiently maintaining the infectivity and virulence of the virus. 52 Recently, comparative studies on SARS-CoV-2 strains isolated from patients in Wuhan (in January 2020) and that isolated from patients in Western countries (predominantly in the US, Spain, and Italy in July 2020) suggests that the virus has accumulated point mutations on its S protein, i.e., D614G, and is currently the predominant strain in the Western world, as shown in Fig. 1.3 . 53 The study also demonstrated clinical evidence that the newly accumulated D614G mutation renders the virus more highly infectious than its original strain; however, the effect of this mutation on severity of the disease is not yet known. 53 Currently, not much has been understood regarding the immunity achieved upon infection, although it appears that the severity of the infection is linked to the larger amount of the antibodies produced. 54 However, current scientific reports support the possibility of SARS-CoV-2 reinfection in individuals who have already had COVID-19, i.e., the antibodies produced by the body against this SARS-CoV-2 could last for a month or less, thus leaving a previously affected individual once again vulnerable to the disease. 55, 56 This appears to be a unique feature of SARS-CoV-2 compared to infections from other known infectious coronaviruses. In the past, researchers have observed that the antibodies created in the infected individuals protected them for a maximum period of three years. 57 Thus, a reinfection of masses and multiple waves of coronavirus infection is a great possibility until mass vaccination is initiated. A deeper understanding of the viral transmission, and the advantages and limitations of the current classical diagnostic tools and novel testing approaches are important to highlight the concern and importance of practicing public health safety measures during the current pandemic.

The rapid spread of SARS-CoV-2 across the globe has put the spotlight on the role of SARS-CoV-2 transmission dynamics. 19 Reproduction number (or R 0 ) is a basic parameter that allows us to estimate a disease outbreak and intensity of the infection. R 0 is defined as an average number of secondary infections caused by an affected individual when the individual is introduced to a susceptible population. 58 The knowledge of R 0 of SARS-CoV-2 is a principle tool that aids to assess the current trends and to predict the future trends of viral infectivity, i.e., disease-spreading potential of the virus. The transmission rate of SARS-CoV-2 ranges between R 0 ¼ 2.2 and R 0 ¼ 3.9, i.e., 1 infected person could infect w4 people in the vicinity, while the median R 0 of SARS-CoV-1 and the mean R 0 of MERS were between 0.58 and 0.69 respectively. 53 The higher the R 0 the stronger the human-to-human transmission.

Among the various viral human-to-human transmission routes, three principle routes of transmission have been identified by WHO: 1. Direct or close contact with diseased individuals is a major mode of viral transmission for COVID-19 disease spreading. 59 Presence of susceptible individuals within <1 m distance from the infected person facilitates close contact viral transmission via infected respiratory droplets. 2. Contact with contaminated surfaces: Studies show that SARS-CoV-2 are highly stable over plastic and stainless surfaces and remain viable for a period of at least 72 h. 60 Thus, direct contact with such contaminated surfaces carrying sufficient concentration of the virus induces the disease in susceptible individuals.

Updated insight into COVID-19 disease and health management to combat the pandemic 3. Airborne transmission occurs when a susceptible individual comes in contact with a suspended contaminated respiratory droplet. Liquid droplets of diameter <5 mm can remain suspended in air and are also capable of traveling up to six feet of distance in the course of air. Such suspended droplets are also called as aerosols. 10, 61 An infected individual upon sneezing generates millions of respiratory droplets that could remain suspended in the air for a long period of time and in turn contaminate other individuals nearby. This kind of viral transmission is often observed in mass public gatherings or in crowded places, and in hospital settings where medical procedures were carried on COVID-19-positive patients. Scientists have demonstrated that SARS-CoV-2 remains stable and viable in the air for at least 3 h and over surfaces such as plastic/stainless steel for at least 72 h. 60 Multiple other modes of human-to-human SARS-CoV-2 transmission such as mother-to-child and fecal route transmission have been documented. Overall, the probability of human-to-human transmission of this virus is very high and can occur upon direct or indirect contact with infected respiratory droplets or with contaminated surfaces. 62 An important point to note in this context is that the viral transmission risk is also dependent on other key factors apart from the R 0 factor such as identifying high-risk environments, effective contact tracing for constant monitoring of disease progression, and careful implementation of government health care policies. 63 Worldwide, many nations have adopted different policies to implement classic health care and safety management measures such as use of facial masks, implementing social distancing, etc., to curb the spread of COVID-19. Most common national level health crisis management strategies include imposing nationwide lockdown, curfews that ban outside travels at certain hours, effective isolation and contact tracing, implementing social distancing, and bans on public gatherings and transportation. 15 Strict implementation of such public safety measures has reduced the infection rate by over 50%e60% in many Asian and European countries. 15 For instance, South Korea's success in COVID-19 management is mainly attributed to rapid implementation of strict government policies drafted in collaboration with its scientific community. The country was quick to issue stay-at-home orders, pursued extensive and efficient contact tracing to identify potential cases, and most importantly, provided rapid testing and secured required numbers of personnel to implement strict social crisis management strategies. 64 For a detailed review on all the SARS-CoV-2 transmission modes and updates on detailed government policies to tackle the viral transmission, readers are directed to other excellent reviews. 65 

Clinically, SARS-CoV-2 is infectious to human beings irrespective of age. 66 Younger adults often develop milder symptoms compared to older adults, particularly if the older adult has other existing medical conditions. 67 The median age of infection in adults is w47 years. People with COVID-19 most often develop mild-to-moderate symptoms without the need for medical assistance. Most often over 80% of the COVID-19 patients develop mild respiratory disease in the form of dyspnea (i.e., breathing difficulties). Based on the statements furnished by WHO, most common symptoms reported by COVID-19 patients include fever (i.e., over w99% of the patients develop fever at some stage during their infection period), dry cough, and tiredness. Classical symptoms exhibited by patients include fever above 38 C, fatigue, dry cough, sore throat, diarrhea, and the characteristic shortness of breath that results in hypoxia. 68 Individuals with weakened immune systems or with other chronic illnesses (w10%e20% of the patients) experience severe hypoxia and often require the support of ventilators. 69e71 Body aches, sore throat, diarrhea, loss of taste and smell, skin rashes or finger/ toe discoloration, and headache are among less common symptoms. 72 More serious symptoms include acute to severe breathing difficulties including shortness of breath, chest pain, and/or loss of speech or movement that require immediate medical attention.

Presentation of clinical symptoms occur on an average of 5e6 days postinitial viral exposure, while it could also take up to 11 days for the onset of the symptoms. In some cases, in spite of the infection, the individuals remain asymptomatic. 73 The viral transmission dynamics by such asymptomatic individuals is not very well understood currently.

SARS-CoV-2 primarily infects the human respiratory system and with potential to infect other organs of the body such as brain, liver, stomach, kidneys, etc. 74 The pulmonary infection causes diffuse alveolar damage, which is considered as the first sign of damage. Specific host immune response results in cytokine dysregulation causing massive infiltration of large macrophages and T-cells on the respiratory tract parenchyma and induces pneumocytic proliferation (https://www.ncbi.nlm.nih.gov/pmc/ articles/PMC7152395/). Such massive infiltration of the immune cells can be observed as patches on chest X-ray scans. 75 SARS-CoV-2 can further proceed and infect the gastrointestinal tract particularly targeting the enterocytes where the virus enters and replicates causing diarrhea. 71 Currently, suspected individuals are recommended to undergo serological testing that checks for the presence of antibodies to the virus and molecularbased diagnostic testing such as polymerase chain reaction (PCR) for pathogen detection. SARS-CoV-2 positive individuals are advised to undergo imaging-based diagnosis to assess the lung infection. 76e78 In the following sections, various challenges and new age technologies for pathogen detection and monitoring of disease progression are elaborately discussed.

In addition to the ongoing struggle to contain the pandemic, the countries face major socioeconomic impact. 79, 80 In an attempt to prevent further damage, many governmental authorities have strongly recommended coordination between the medical community and local public health authorities for developing COVID-19 health care management strategies including the use of novel diagnostic testing approaches for rapid pathogen detection. 81 Currently WHO recommended primary confirmatory diagnostic technique includes Nucleic Acid Amplification Tests (NAAT) such as real-time reverse transcriptase PCR (RT-PCR) for SARS-CoV-2 detection 82 (https://www. who.int/publications/i/item/10665-331501). A detailed overview on the principle and method of diagnosis using this technology can be found in Ref. 83 This section provides an overview of analytical issues at various stages of sample collection and processing. It further provides an overview of the primary COVID-19 diagnostic techniques highlighting their advantages and limitations.

As of January 2021, a typical COVID-19 diagnosis relies on genomic detection of SARS-CoV-2 from the respiratory tract samples such as nasopharyngeal (NP) swabs and/or an oropharyngeal (OP) swabs collected of suspected individuals. 84, 85 The collected sample is placed into a viral transportation medium and is transported to nearby clinical laboratories for analysis. 86, 87 Molecular diagnostic analysis based on nucleic acid amplification such as RT-PCR is performed to detect the pathogen in the collected sample. 88 One of the most common issues regarding RT-PCR is the obtention of false-negative results, i.e., pathogens could go undetected in the patient sample. The rate of obtention of false-negative results are in the range of w2%e29%. 89 The false negative results pose a greater risk to society, since such individuals could further spread the disease adding to the difficulty in containing the virus outbreak. 90 To reduce such false negatives, technical issues must be well considered and addressed. For instance, technical issues such as stability of the RNA sample collected, the time of swab collection (i.e., the NP/OP swabs should be taken at the onset of the symptoms as viral loads tend to be higher in the region around this time), and swift swab collection procedures (i.e., collection of respiratory samples particularly NP/OP swabs requires proper prior training). 91 Mishandling of such airborne pathogens during sample collection, handling, and transportation could be dangerous and would lead to a new outbreak of the disease among health care professionals. Such hazardous situations could be avoided by providing adequate formal training and sufficient supply of personal protective equipment (PPE) to all health care professionals dealing with COVID-19 samples and patients. The reuse of the sample processing kits should be avoided under all circumstances. 92 Thus, practicing safe and recommended methods of sample collection and maintenance of high hygienic standards in places of sample collection, manipulation, and storage are important steps toward ensuring safe diagnosis of COVID-19 in suspected individuals.

Clinical diagnosis of COVID-19 disease is based on observation of symptoms, epidemiological history, and testing by standard molecular testing methods. Currently, the three most commonly used as molecular diagnosis for SARS-CoV-2 are RT-PCR, Loop-Mediated Isothermal Amplification (LAMP) and high-throughput Next Generation Sequencing (NGS) of the whole genome. 93 However, exploitation of NGS technology is limited due to its dependency on many instrumentations and the expenses incurred for such analyses. On the other hand, RT-PCR and RT-LAMP are costeffective and straightforward technologies that allow the detection of pathogenic diseases. In addition, these techniques are portable, rapid, and robust in nature, requiring less instrumentation. 94 Currently, many new biosensors and nanomaterials-based techniques are being developed for the detection of infectious diseases particularly useful in the current scenario. 95e97 In the following sections, a brief overview of the three classical techniques listed above is presented.

Updated insight into COVID-19 disease and health management to combat the pandemic

RT-PCR is one of the current standard method for COVID-19 detection. Respiratory samples such as NP/OP swabs collected from suspected individuals are processed to obtain the pathogenic genomic material, i.e., RNA as the source material, which is then subjected to nucleic acid amplification techniques such as RT-PCR. RT-PCR uses the reverse transcriptase enzyme to convert the RNA material obtained from the sample into complementary DNA (cDNA), which is further amplified using a DNA polymerase and primers to specific biomarker genes. 98 The technology uses fluorescent primers to amplify the genes under investigation. This facilitates real-time quantification of the relative expression of the biomarker's genes in the sample. Thus, higher expression of viral genes compared to various control samples is considered as a positive outcome for the assay. For SARS-CoV-2 diagnosis, viral genes such as N, E, S, and RdRp are being used as biomarkers. 99 SARS-CoV-2 positive samples are further confirmed by whole genome sequencing such as NGS technology. 82 In spite of having multiple advantages (listed in the introduction of this section), there are some limitations in using the RT-PCR-based diagnosis. 100 As suspected cases of COVID-19 are surging, necessitating the rapid detection of the virus, limitations of RT-PCR based detection techniques for COVID-19 disease is more profoundly visible now than before. 101 Limitations in the detection technique include unreliable stability of the results, i.e., the efficiency of target gene and control gene do not remain identical at all times, obtention of false positive and negative results, and the unverified clinical significance of positive PCR amplicons. These are among the key issues that need to be addressed. 102, 103 Multiple factors influence the molecular test, such as condition of the sample obtained, anatomical location from where it was extracted, the time of disease, i.e., the stage or the phase of the disease in the individual, and time spent for sample transportation. 104 In addition, the RT-PCR is time and labor consuming. Other methods of isothermal amplification of nucleic acids such LAMPs, antigen-based serological tests, and serum antibody tests could provide solutions to these issues.

LAMP assays are a robust, highly sensitive, high accuracy, and rapid diagnostic tool for SARS-CoV-2 detection. 105e109 It is a popular choice point-of-care (POC) technique employed for rapid COVID-19 testing. 110 This promising nucleic acid LAMP amplification technique uses six different target sequences for the same viral gene, which increases the sensitivity and specificity of the process. 111 Moreover, as LAMP does not require expensive instruments and reagents, it is highly cost-effective. The technique uses one single heat block for nucleic acid amplification process, and results can be obtained in less than 60 min. 111 These are the critical advantages of the technique that improve cost reduction and assist in rapid COVID-19 detection at this crucial time. 112 Recently, researchers have developed colorimetry-based reverse transcriptase LAMP (RT-LAMP) technique for further rapid detection of COVID-19 that allows one-step reverse transcription, which can be detected by a color change and is visible to the naked eyes. 110 Yu et al. developed the RT-LAMP technique for the detection of genomic RNA from SARS-CoV-2 strain and showed that technique has a limit of detection (LOD) up to 100 copies/reaction, thus demonstrating that the technique has very high sensitivity for pathogen identification. They also experimented on various other strains of coronaviruses such as human coronaviruses (hCoV-229E, hCoV-OC43), Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV2 ( Fig. 1.4) . They claimed that this RT-LAMP process is highly specific for detection of SARS-CoV-2, and due to the colorimetric method, this tool can be exploited as a potential POC test for COVID-19 detection in the near future. 113 This technique, however, has a few limitations, such as requiring high sample purity, sophisticated sample processing steps, issues regarding result reproducibility, and in some cases, sample stability issues have also been reported. 114, 115 Currently, research is aimed at developing the techniques suitable for POC testing.

NGS is an emerging technology that can potentially overcome some of the limitations mentioned earlier and can efficiently cater to the growing diagnostic demand. For quite some time, NGS has been used as tool to study and understand the genomic details of a pathogen. For instance, at the initial stage of SARS-CoV-2 outbreak NGS technology was used for identification and discovery of the viral strain. 116e118 Early identification of this virus has helped to conduct rapid and promising advanced research on the virus, which has led to the rapid production of medicines and vaccines against viral infection. 119, 120 Later, RT-PCR techniques helped to detect the specific sequences of the SARS-CoV-2 genome. Moreover, NGS tools have been instrumental for identification and detection of the mutation frequency in the virus and thus providing a detailed overview of the evolution of the virus over time. 121, 122 Nanopore sequencing is a third-generation sequencing technique that has been used for detailed viral genome analysis from various clinical specimens. 123, 124 This technology also measures RNA molecules from the viral genomic sample without the necessity of generating cDNA for analysis. Such techniques offer complete genome information of the pathogen, thus providing novel research insights that help in understanding the nature of the pathogen. 117 The use of computational tools for analyzing the sequencing data including the genome analyses using NCBI's Basic Local Alignment Search Tool (BLAST) is often time and labor consuming to generate whole outcomes. 125, 126 Thus, such genome analysis techniques are highly expensive and time-consuming compared to simple RT-PCR, RT-LAMP, or other molecular diagnostic assays. 

Antigen-based detection techniques employ patient serum and detect antigens present in patient samples. Many antigen detection techniques are highly sensitive, robust and rapid. Antigen-based detection techniques are currently available in the market. Many serology-based tests are highly compatible with high-throughput analysis, i.e., thousands of samples could be processed in very less time compared to conventional techniques. 127 The success of such serology-based tests and their commercialization will provide rapid answers to suspected COVID-19 patients, and subsequently contribute to increased efficiency in contact tracing and precautionary isolation approaches that will truly contribute to efficient containment of the disease. 128e130 Although such techniques are highly specific, they are very sensitive to the mutations accumulated by the RNA, i.e., they cannot successfully identify the pathogen, should they evolve over time. In spite of the aforementioned issues, the capacity of the technology for rapid COVID-19 detection testing has powered the advancement of various serological approaches. 131 Many nations worldwide have exploited such serological methods for initiating surveillance of suspected individuals. For example, as of January 31, 2020, Singapore has employed more serological based SARS-CoV-2 testing than the traditional RT-PCR technique for mass COVID-19 testing in the country. They have been successful in identifying many positive cases using this approach. 132 A major advantage of this technique is that many asymptomatic patients have also been diagnosed as COVID-19 positive since this technique involves detection of antigens and antibodies in the patient samples. 133 Hence, alongside molecular testing, application of serological testing is also an important assay.

In spite of all these advantages, these antigen-based detections have few limitations, such as the importance of time of sample collection, i.e., often antigen productions are low at the initial phase of the symptom onset, low sensitivity of the technique, potential false-negative results, chances of cross-contamination with closely similar antigens, requirement of trained personnel for sample obtention, requirement of a preenrichment processes. 134, 135 Further development on ELISA-based detection is continuing and near future these problems will be resolved.

Various biomolecular and immunoassays have been developed for the rapid detection of SARS-CoV-2. Assay selection is an important issue for efficient detection of SARS-CoV2. Few important POC immunoassays that are currently employed for the detection of the virus are lateral flow assays (LFAs), serological assays, and high-throughput immunoanalyzer assays. 136 The LFA process identifies antigens of SARS-CoV-2 by detecting antibodies such as IgM and IgG against COVID-19 disease. 137 This immunoassay, similar to qRT-PCR process, offers rapid and costeffective detection of the virus. However, this assay is not as sensitive as other biomolecular assays ( 141, 142 Thus, the ongoing research, on the one hand, is looking for specific monoclonal antibodies against SARS-CoV-2, and on the other, is searching for other speedy antigen detection assays that can be reliably employed for the diagnosis of COVID-19. 143 Assay selection for molecular detection of SARS-CoV-2 is also a current issue. Rapid amplification-based sequencing methods play a key role in the detection of the disease. The preliminary quick and robust detection is performed using molecular techniques such as qRT-PCR, RT-PCR, and RT-LAMP process. 149 A complete genome analysis is performed using NGS platforms in the second stage of further confirmation of the virus in positive samples. 150 RT-PCR assay is the most commonly employed molecular technique in the first stage of the virus detection in patient samples. 6 Other molecular methods, such as LAMP, CRISPR-Cas9, and microarray-based techniques have shown great potential for the detection of the disease. 107,151e153 One of the major advantages of these molecular techniques is that the sample is amplified before analysis, and such amplification procedures significantly reduce the false-positive results. This helps to avoid amplicon contamination. These techniques are highly specific, and since only a few strains of coronaviruses that cause respiratory disorders are circulating at the moment, such high specificity is another added advantage for these techniques. 154 The aforementioned advantages could also prove to be a limitation since both SARS-CoV and SARS-CoV-2 are a group of SARS-like bat origin coronaviruses. 155 Therefore, there is a possibility and risk for making nonspecific molecular observations in some samples. To overcome such issues regarding nonspecificity, the WHO and CDC recommends the use of at least two molecular assays for testing for instance, the first-line screening with E gene assay followed by RdRp gene assay as confirmatory examination. 94 

Generally, late detection of patients or asymptomatic individuals are problematic in terms of isolating infected patients from healthy populations. Many studies indicated that the viral loads of SARS-CoV-2 RNA is immensely high in the bronchoalveolar specimens, i.e., deep respiratory samples than Nasal/oral swabs. 156 Thus, the typical samples such as the sputum or bronchoalveolar specimens collected from lower respiratory tract contain the highest SARS-CoV-2 viral loads. 157 A recent study reported that the positive samples collected from bronchoalveolar lavage fluid showed the highest number of viral loads present in the sample. 156 The classic symptoms of COVID-19 can be two types, such as mild and severe. Mild symptoms are generally cough, fever, mild headache, sneezing, and fatigue. 158 However, these mild symptoms are similar symptoms of flu/ influenza. 159 Sometimes, it may be confusing to differentiate between normal flu and COVID-19 because of such mild symptoms until severe symptoms such as lung congestion and shortness of breath appear. 160 By this time, it is often too late to treat the infected patient. Such patients must be admitted to a hospital, particularly to the intensive care unit (ICU) and may probably need life support. Alternatively, some studies have also reported patients with high viral loads of SARS-CoV-2 in their fecal material. 20, 161 Therefore, for COVID-19 testing with swabs from respiratory tracts are not sufficient. Other studies have also reported SARS-CoV-2 viral loads from enterocytes in the digestive tract by means of electron microscopy. 81 Thus, for efficient sample collection and diagnosis, multiple swab samples should be obtained from the same suspected patients. 162,163

Continuous monitoring of critically ill COVID-19 patients is a great challenge. Critical patients have a high amount of SARS-CoV-2 RNA load in their body organs. Since higher viral loads have also been found in fecal material and in the respiratory tract of the infected patients, analyzing at least two samples from patients at the beginning of hospital admission is very crucial for patient monitoring. 156, 162, 164, 165 Practicing standard hygienic practices such as thorough cleaning is mandatory, especially in the Updated insight into COVID-19 disease and health management to combat the pandemic clinical houses or hospitals, objects/articles that are related to COVID-19 patients, and the patient-frequented washrooms. Listed below are the CDC guidelines for maintaining high hygienic standards while handling COVID-19 patients, their clinical samples, and other related articles 166, 167 :

(1) At the preliminary stage, the container containing the obtained patient sample should be sealed with a screw cap. It must inform the patient on the spot of examination centers. (2) The container must have low risk of breakage and low chances of contamination, so it is suggested to carry a cotton swab inside a conical tube. Currently real-time RT-PCR is being used for COVID-19 diagnosis. (10) While using commercial kits, the instructions and all other manufacture information should be followed properly. (11) To prevent the chances of cross-contamination during RNA extractions and pre-PCR process personnel need to take care of extra precautions and should follow the guidelines of biosafety rules. Personnel should wear gloves, masks, gown, and eye protection in a BL2 laboratory. (12) At the end, all infectious waste such as residual specimens, contaminated reagents, PPE, tips, etc., should be properly disposed by following the institute recommended guidelines of handling infectious waste samples.

Further, the contaminated patient samples like swabs, stool cultures, surfaces, and instruments such as PCR machine, electron microscopy, and CT scanners have to be handled with extra attention, and proper sanitization protocols should be followed. 168 Some studies claim that handling respiratory samples are harder than handling stool samples from the patients because of the presence of higher viral loads in respiratory samples than in stools samples. 169 Currently, the preferred method for detecting SARS-CoV-2 is real-time PCR technique from a respiratory swab sample. 162 This pandemic situation has resulted in a high level of work stress among health care professionals who face the danger of being directly exposed to SARS-CoV-2 on a daily basis. The high-level work stress, long periods of confinement, and self-isolation approaches have negatively impacted mental health, giving rise to problems/issues such as depression and anxiety. 171 Pressure of loss of jobs due to economic recession and loss of loved ones due to COVID-19 bring greater risk of psychological stress in such individuals. 172 To reduce such mental pressures among health care professionals, equal work distribution should be made practical. The governing authorities and health care policy makers should undertake strong management factors with good leadership to support health care professionals and families. Fig. 1 .5 shows few health managements factors that are necessary for maximal effective containment of virus. This section of the chapter also discusses other health management factors for other health issues caused by COVID-19.

As mentioned earlier, early detection of COVID-19 with gold standard technologies are necessary alongside a few other issues that should be considered, for instance, postvaccination surveillance, 173 and the timely evaluation of preexisting medical risks that could trigger another disease outbreak causing further damage. 174 In general, the requirement of the Updated insight into COVID-19 disease and health management to combat the pandemic physical presence of health care professionals in close proximity to the COVID-19 patients for treatments and other purposes poses a great risk and increases the chance of direct contamination with the virus manifold times. Thus, proper health care management is required to reduce such risks. For instance, the increase in the number of health care professionals dealing with COVID-19 patients and samples, and adequate production and supply of PPE are essential in addition to rapid COVID-19 testing on a daily basis.

The requirement of proper environmental waste management strategies is a highly significant, growing concern as each day passes during this pandemic. Due to large-scale disposing of huge amounts of medical and domestic waste on a daily basis, environmental pollution is becoming a more serious problem. Medical and domestic waste in many countries such as China, USA, Spain, and Italy has increased in excessive quantities. 175 Reports indicate that in Wuhan, over 240 metric tons of contaminated medical waste are being generated on a daily basis. 176 Household waste has also increased due to online shopping and home delivery options, which are not getting recycled. 177, 178 Because of the fear of further spreading of the virus, used and contaminated articles such as gloves, masks, expired medications, and other contaminated PPE cannot be recycled. 178 In future, researchers need to focus on more recycling and disposing processes of medical and domestic waste.

Telehealth management is one of the best approaches to guide and advise patients. This approach optimizes in mitigating the risk of exposure, and thus is an excellent initiative toward reducing the spread of the virus. In the past, telehealth had been suggested due to a huge number of patients queries and the phone consulting facilitated appropriate medical care without the need for huge patient lines and/or waiting time. 179 The main aim for implementing telehealth management is to provide access to health care systems from rural areas. 180 However, in the recent scenario of COVID-19, telehealth management is proving to be a great boon. This management is used across all the medical specialties for maintaining patient access to care while successfully maintaining physical distance from the patients. 181 For example, hospital admission formalities of a COVID-19 patients such as information about the patient history and the current status of COVID-19 disease can be done using telehealth systems. In general, Updated insight into COVID-19 disease and health management to combat the pandemic through this management process, consultants will directly discuss with patients and provide them the required services during the telehealth consulting sessions. This way, telehealth care reduces by half the number of patients visiting the medical center and successfully avoids the exposure of low-risk patients to the virus in hospital settings. 182 The study by Aziz et al. provides a new norm for handling medical visits for pregnant women under the current COVID-19 circumstances. The authors demonstrated that medical consultations of pregnant women who are in <11 weeks of gestation, i.e., the first doctor visit could also be done virtually where patient's clinical history can be taken. Genetic screening and clinical requirements could be reviewed. At a later stage, around 11e14 weeks of gestation, physical examination and prenatal blood examinations could be performed. The following 4 weeks, patient could continue to meet their doctors virtually depending upon the examination reports. Further medical visits of the patient up until the time of delivery could be virtual or on site depending on the patient's condition, while physical presence would be required for an ultrasound examination. 182 By following such practices, the exposure of high-risk and low-risk patients can be significantly reduced, which will play a major role in exposure prevention. 183 

Many findings have reported that traces of SARS-CoV-2 is found in wastewater along with particles of disinfecting elements. 184 The byproducts of disinfectants cause toxicity in wastewater and discharges into rivers and oceans, which is spoiling the environment and public health indirectly. 185 The record from UN's world water development showed the 80% of wastewater is polluting the environment without enough treatment process. 186 One of the studies by Wang et al. stated that SARS-CoV strain was found in medical waste, domestic sewage, and tap water, which has led to fast spread of the virus. 187 Hence, the cleaning and treatment process and proper waste management is highly necessary for containment of the COVID-19 situation. To reduce the chances of virus and the quantity of disinfectant in wastewater, large-scale waste management strategies and treatment plants could be set up. 188 In such situations, the industrial partners and governmental agencies should come forward and work together for the establishment of a central wastewater treatment setup that will benefit everyone.

Besides the aforementioned health management issues and strategies, there are a few other factors on which we must focus. For instance, increasing home confinements have drastically increased the concept of online food and article shopping. With increased home delivery of food, groceries, and other products, proper sanitization protocols and minimal contact with people should be strictly followed by the delivery and transportation system to minimize the risk for further virus spread. The CDC has laid proper guidelines that should be followed to minimize such risks. In addition, as side effects to some health management strategies, other mental health issues such depression, anxiety, and other disparities have been reported in some people due to long periods of nationwide lockdowns, self-isolation, and quarantine rules. 189, 190 Therefore, a good balance in implementing the health management strategies considering all of these factors is necessary to successfully overcome this pandemic.

This chapter provides an overview of the COVID-19 disease caused by SARS-CoV-2, the responsible viral agent for the currently ongoing pandemic and world health crisis that has killed millions of people worldwide. A brief history, evolution, transmission of this virus, and comparisons of various diagnostic technologies are reported in this chapter. In addition to this, preventive measures by CDC and WHO are listed along with many health management factors that are discussed in this chapter. SARS-CoV-2 is a zoonotic virus and is thought to have spread from the Wuhan's live seafood markets in the Hubei province of China. The salient features of this virus such as the high replication rate, very high human-to-human transmission capacity, the potential to infect most body parts, and the persistent virulence of the virus over contaminated surfaces has made it one of the deadliest pathogens known to mankind. Therefore, understanding the origin and nature of the virus, the route of transmission, mode of interaction with host, and pathogenesis are essential for developing better medications, effective therapeutics, and vaccines to overcome this pandemic.

Among the various health management strategies implemented by various nations across the globe, lessons should be learned from nations that have been successful in implementing the public health management policies. Few health care management factors listed in this chapter such as adequate support to health care professionals and provisions for health care facilities, appropriate use of diagnostic tools and advances in technologies for monitoring the disease spread, and proper establishment of waste management are essential to contain the virus spread. Thus, ensuring a proper health care risk assessment, rapid establishment of the governmental health care management strategies upon careful consideration of a wide range of health care factors mentioned in this chapter could help to achieve success in containing the current pandemic, further preventing more human loss.

Since COVID-19 first emerged in December 2019, the scientific communities, public authorities, private enterprises, and people around the globe have relentlessly contributed to the efforts initiated by their countries during the pandemic. We hope that vaccines and better medications should soon reach all the people and that the world returns to normalcy.

Fields virology

COVID-19: a novel zoonotic disease caused by a coronavirus from China: what we know and what we don't

Unraveling the zoonotic origin and transmission of SARS-CoV-2

Comparing SARS-CoV-2 with SARS-CoV and influenza pandemics

High contagiousness and rapid spread of severe acute respiratory syndrome coronavirus 2

A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster

Community transmission of severe acute respiratory syndrome coronavirus 2

Shedding of SARS-CoV-2 in feces and urine and its potential role in person-to-person transmission and the environmentbased spread of COVID-19

Influence of wind and relative humidity on the social distancing effectiveness to prevent COVID-19 airborne transmission: a numerical study

Airborne transmission of SARS-CoV-2: theoretical considerations and available evidence

COVID-19 and the demand for online food shopping services: empirical evidence from Taiwan

Whose coronavirus strategy worked best? Scientists hunt most effective policies

Covid-19 impact on Asia and beyond

Current response and management decisions of the European union to the COVID-19 outbreak: a review

Lessons learnt from easing COVID-19 restrictions: an analysis of countries and regions in Asia Pacific and Europe

Responding to COVID-19: the experience from Italy and recommendations for management and prevention

COVID-19 to plunge global economy into worst recession since World War II

Early clinical characteristics of Covid-19: scoping review. medRxiv

Virology, transmission, and pathogenesis of SARS-CoV-2

Coronavirus infectionsdmore than just the common cold

Novel vaccine technologies: essential components of an adequate response to emerging viral diseases

Comparative therapeutic efficacy of remdesivir and combination lopinavir, ritonavir, and interferon beta against MERS-CoV

Viral targets for vaccines against COVID-19

An update on molecular diagnostics for COVID-19

Vaccines for COVID-19: the current state of play

Concerns and motivations about COVID-19 vaccination

Strategies for the prevention and management of coronavirus disease 2019

COVID-19: a 2020 update

Testing for COVID-19: a way to lift confinement restrictions

The species severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2

Genomic determinants of pathogenicity in SARS-CoV-2 and other human coronaviruses

Commentary: origin and evolution of pathogenic coronaviruses

Human coronavirus: host-pathogen interaction

Coagulation disorders in coronavirus infected patients: COVID-19, SARS-CoV-1, MERS-CoV and lessons from the past

Novel coronavirus 2019-nCoV: prevalence, biological and clinical characteristics comparison with SARS-CoV and MERS-CoV

Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2. bioRxiv

SARS-CoV-2 RNA polymerase as target for antiviral therapy

The origin of SARS-CoV-2

The proximal origin of SARS-CoV-2

A palindromic RNA sequence as a common breakpoint contributor to copy-choice recombination in SARS-COV-2

Widespread coronavirus infection in Ghanaian bats: seasonal, demographic and ecological factors influence infection risk. Epidemiology and ecology of virus and host: bats and coronaviruses in Ghana, West Africa. 2015. p. 30. 42. Bar-On YM, Flamholz A, Phillips R, Milo R. SARS-CoV-2 (COVID-19) by the numbers

The strengths of scanning electron microscopy in deciphering SARS-CoV-2 infectious cycle

Potential therapeutic options for COVID-19: current status, challenges, and future perspectives

In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges

Structural basis for the recognition of SARS-CoV-2 by full-length human ACE2

Relationship of SARS-CoV to other pathogenic RNA viruses explored by tetranucleotide usage profiling

Genomic diversity and evolution, diagnosis, prevention, and therapeutics of the pandemic COVID-19 disease

An overall picture of SARS coronavirus (SARS-CoV) genome-encoded major proteins: structures, functions and drug development

Possible host-adaptation of SARS-CoV-2 due to improved ACE2 receptor binding in mink

Mechanisms of host receptor adaptation by severe acute respiratory syndrome coronavirus

The molecular biology of intracellular events during Coronavirus infection cycle

Tracking changes in SARS-CoV-2 spike: evidence that D614G increases infectivity of the COVID-19 virus

Coronaviruses and toroviruses. Principles and practice of clinical virology

Syncytia formation by SARS-CoV-2-infected cells

SARS-CoV-2 antibody responses correlate with resolution of RNAemia but are short-lived in patients with mild illness. medRxiv

Six months of coronavirus: the mysteries scientists are still racing to solve

Early release-high contagiousness and rapid spread of severe acute respiratory syndrome coronavirus 2

Transmission of SARS-CoV-2: implications for infection prevention precautions: scientific brief

Stability of SARS-CoV-2 and other coronaviruses in the environment and on common touch surfaces and the influence of climatic conditions: a review

Airborne transmission route of COVID-19: why 2 meters/6 feet of inter-personal distance could not Be enough

Coughs and sneezes: their role in transmission of respiratory viral infections, including SARS-CoV-2

SARS-CoV-2 transmission dynamics should inform policy

Policy learning and crisis policy-making: quadruple-loop learning and COVID-19 responses in South Korea

How experts use data to identify emerging COVID-19 success stories. Our World in Data

Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72 314 cases from the Chinese center for disease control and prevention

Clinical characteristics of 138 hospitalized patients with 2019 novel coronaviruseinfected pneumonia in Wuhan

Review of the 2019 novel coronavirus (SARS-CoV-2) based on current

Human coronaviruses and other respiratory viruses: underestimated opportunistic pathogens of the central nervous system?

Neurological manifestations of severe SARS-CoV-2 infection: potential mechanisms and implications of individualized mechanical ventilation settings

Human coronaviruses

Clinical presentation and management of COVID-19

Asymptomatic transmission of covid-19

Studies on viral pneumonia related to novel coronavirus SARS-CoV-2, SARS-CoV, and MERS-CoV: a literature review

Review of the 2019 novel coronavirus (SARS-CoV-2) based on current evidence

A role for CT in COVID-19? What data really tell us so far

Heart and lung multimodality imaging in COVID-19

Review of artificial intelligence techniques in imaging data acquisition, segmentation and diagnosis for COVID-19

Economic effects of coronavirus outbreak (COVID-19) on the world economy. Available at SSRN 3557504

Potential indirect effects of the COVID-19 pandemic on use of emergency departments for acute life-threatening conditions d United States

Laboratory diagnosis of COVID-19: current issues and challenges

Laboratory testing of 2019 novel coronavirus ( 2019-nCoV) in suspected human cases: interim guidance

Real-time RT-PCR in COVID-19 detection: issues affecting the results

Diverse molecular techniques for early diagnosis of COVID-19 and other coronaviruses

Optimum nasooropharyngeal swab procedure for COVID-19: step by step preparation and technical hints

SARS-CoV-2 viral load in upper respiratory specimens of infected patients

Evaluation of swabs, transport media, and specimen transport conditions for optimal detection of viruses by PCR

Report from the American society for microbiology COVID-19 international summit

False-negative results of initial RT-PCR assays for COVID-19: a systematic review

Diagnostic strategies for COVID-19 and other coronaviruses

Viral load of SARS-CoV-2 in clinical samples

Barriers and facilitators of adherence to social distancing recommendations during COVID-19 among a large international sample of adults

Molecular immune pathogenesis and diagnosis of COVID-19

Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR

Chapter 10 -nanotherapeutics: a novel and powerful approach in modern healthcare system

Chapter 9 -cancer cytosensing approaches in miniaturized settings based on advanced nanomaterials and biosensors

Modernization of biosensing strategies for the development of lab-on-chip integrated systems

The use of real-time reverse transcriptase PCR for the quantification of cytokine gene expression

In vitro diagnostic assays for COVID-19: recent advances and emerging trends

Covid 19: where's the strategy for testing?

Correlation of chest CT and RT-PCR testing for coronavirus disease 2019 (COVID-19) in China: a report of 1014 cases

PCR-based diagnostics for infectious diseases: uses, limitations, and future applications in acute-care settings

Quantification using real-time PCR technology: applications and limitations

Biosafety concerns during the collection, transportation, and processing of COVID-19 samples for diagnosis

Meat species identification using DNAredox electrostatic interactions and non-specific adsorption on graphene biochips

A novel, sensitive and label-free loop-mediated isothermal amplification detection method for nucleic acids using luminophore dyes

Paper-based rapid detection of pork and chicken using LAMPemagnetic bead aggregates

Uddin Ahmed M. Meat species identification using DNAluminol interaction and their slow diffusion onto the biochip surface

Colorimetric nucleic acid detection on paper microchip using loop mediated isothermal amplification and crystal violet dye

Rapid colorimetric detection of COVID-19 coronavirus using a reverse tran-scriptional loop-mediated isothermal amplification (RT-LAMP) diagnostic plat-form: iLACO. medRxiv

Loop-mediated isothermal amplification of DNA

Loop mediated isothermal amplification (LAMP) assays as a rapid diagnostic for COVID-19

Development of reverse transcription loop-mediated isothermal amplification assays targeting severe acute respiratory syndrome coronavirus 2

Rapid diagnosis of H5N1 avian influenza virus infection by newly developed influenza H5 hemagglutinin gene-specific loopmediated isothermal amplification method

Drawback of loop-mediated isothermal amplification

Clinical manifestation, diagnosis, prevention and control of SARS-CoV-2 (COVID-19) during the outbreak period

Molecular diagnosis of COVID-19: challenges and research needs

Pooling RT-PCR or NGS samples has the potential to cost-effectively generate estimates of COVID-19 prevalence in resource limited environments. medRxiv

A new coronavirus associated with human respiratory disease in China

Discovery of a novel coronavirus associated with the recent pneumonia outbreak in humans and its potential bat origin. bioRxiv

Identification and survey of a novel avian coronavirus in ducks

Complete genome sequence of a hemagglutination-negative avian paramyxovirus type 4 isolated from China

MasterOfPores: a workflow for the analysis of oxford nanopore direct RNA sequencing datasets

The architecture of SARS-CoV-2 transcriptome

Computational tools for copy number variation (CNV) detection using next-generation sequencing data: features and perspectives

Comparison of next-generation sequencing systems

Laboratory-based diagnosis of brucellosisea review of the literature. Part I: techniques for direct detection and identification of Brucella spp

Advancements in the diagnosis of bacterial plant pathogens: an overview

Serology-based diagnostics for the control of bovine neosporosis

A rapid blood test to determine the active status and duration of acute viral infection

COVID-19 clinical diagnostics and testing technology

Connecting clusters of COVID-19: an epidemiological and serological investigation

High prevalence of asymptomatic COVID-19 infection in hemodialysis patients detected using serologic screening

Rapid methods for the detection of foodborne bacterial pathogens: principles, applications, advantages and limitations

Diagnosis of tuberculosis: available technologies, limitations, and possibilities

The COVID-19 serology studies workshop: recommendations and challenges

Four point-of-care lateral flow immunoassays for diagnosis of COVID-19 and for assessing dynamics of antibody responses to SARS-CoV-2

A highly specific rapid antigen detection assay for on-site diagnosis of MERS

Comparison of immunofluorescence with monoclonal antibodies and RT-PCR for the detection of human coronaviruses 229E and OC43 in cell culture

Immunofluorescence assay for detection of the nucleocapsid antigen of the severe acute respiratory syndrome (SARS)-Associated coronavirus in cells derived from throat wash samples of patients with SARS

Viral kinetics and antibody responses in patients with COVID-19. medRxiv

COVID-19: current trends in invitro diagnostics

Diagnosis of acute respiratory syndrome coronavirus 2 infection by detection of nucleocapsid protein. medRxiv

Improved molecular diagnosis of COVID-19 by the novel, highly sensitive and specific COVID-19-RdRp/Hel real-time reverse transcription-PCR assay validated in vitro and with clinical specimens

Novel one-step single-tube nested quantitative realtime PCR assay for highly sensitive detection of SARS-CoV-2

COVID-19: molecular and serological detection methods

Homogeneous circle-to-circle amplification for real-time optomagnetic detection of SARS-CoV-2 RdRp coding sequence

Current status of laboratory diagnosis for COVID-19: a narrative review

Clinical evaluation of self-collected saliva by quantitative reverse transcription-PCR (RT-qPCR), direct RT-qPCR, reverse transcriptioneloop-mediated isothermal amplification, and a rapid antigen test to diagnose COVID-19

A pneumonia outbreak associated with a new coronavirus of probable bat origin

Era of molecular diagnosis for pathogen identification of unexplained pneumonia, lessons to be learned

Based visual detection of Salmonella bacteria using isothermal DNA amplification and magnetic bead aggregation

Chapter 16 isothermal dna amplification strategies for food biosensors

Origin and evolution of pathogenic coronaviruses

Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding

Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes

Differential sensitivities of severe acute respiratory syndrome (SARS) coronavirus spike polypeptide enzyme-linked immunosorbent assay (ELISA) and SARS coronavirus nucleocapsid protein ELISA for serodiagnosis of SARS coronavirus pneumonia

Mild or moderate covid-19

Featuring COVID-19 cases via screening symptomatic patients with epidemiologic link during flu season in a medical center of central Taiwan

Lopinavir/ritonavir is associated with pneumonia resolution in COVID-19 patients with influenza coinfection: a retrospective matchedpair cohort study

Laboratory diagnosis of emerging human coronavirus infections e the state of the art

Severe acute respiratory syndrome associated coronavirus is detected in intestinal tissues of fatal cases

Enteric involvement of coronaviruses: is faecaleoral transmission of SARS-CoV-2 possible?

Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore

Viral shedding patterns of coronavirus in patients with probable severe acute respiratory syndrome

Guidelines for laboratory diagnosis of coronavirus disease 2019 (COVID-19) in Korea

Valorization of disposable COVID-19 mask through the thermo-chemical process

Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals

Transmission routes analysis of SARS-CoV-2: a systematic review and case report. Hypothesis and theory

Syndromic surveillance in public health practice

Mental health in the COVID-19 pandemic

The mental health of doctors during the COVID-19 pandemic

Immunotherapeutics for Covid-19 and post vaccination surveillance

Three-dimensional printing in the fight against novel virus COVID-19: technology helping society during an infectious disease pandemic

COVID-19 and the environment: a critical review and research agenda

Novel coronavirus disease 2019 (COVID-19) pandemic: considerations for the biomedical waste sector in India

Challenges, opportunities, and innovations for effective solid waste management during and post COVID-19 pandemic

Indirect effects of COVID-19 on the environment

The role of telehealth in the medical response to disasters

Opportunities and challenges of telehealth in remote communities: case study of the Yukon telehealth system

Virtually perfect? Telemedicine for covid-19

Telehealth for high-risk pregnancies in the setting of the COVID-19 pandemic

A population health segmentation framework for balancing medical need and COVID-19 risk during and after the pandemic

SARS-CoV-2 from faeces to wastewater treatment: what do we know? A review

Post Covid-19 water and waste water management to protect public health and geoenvironment

Existence of SARS-CoV-2 in wastewater: implications for its environmental transmission in developing communities

Study on the resistance of severe acute respiratory syndrome-associated coronavirus

Concerns and strategies for wastewater treatment during COVID-19 pandemic to stop plausible transmission

Mental health impact of COVID-19 on police personnel in India

Mental-health-related admissions to the acute medical unit during COVID-19