Clinical, molecular, and epidemiological characterization of the SARS-CoV-2 virus and the Coronavirus Disease 2019 COVID-19, a comprehensive literature review PMC

Bai H.X., Hsieh B., Xiong Z., Halsey K., Choi J.W., Tran T.M.L. Performance of radiologists in differentiating COVID-19 from viral pneumonia on chest CT. The pharmaceutical companies that are currently on a race to produce a vaccine for COVID-19 along with the vaccine developing strategies they are using are summarized in Table 8and Fig. Virus elimination via the stool even after the negativity in the nasopharyngeal mucosa and the disappearance of symptoms makes them a potential source of contagion through the fecal-oral route (Lee et al., 2020). Abnormal radiological findings are found in asymptomatic children and consist of bilateral lung lesions (50%). Elevated CRP (C – reactive protein), Procalcitonin PCT (80%), and liver enzymes are present in most affected children, unlike adults in whom PCT is not a reliable marker. It is interesting to know if there is an increased risk of acquiring a SARS-CoV-2 infection as a person living with HIV .

In addition, it is important to highlight that because serological tests depend on the ability to produce antibodies, intrinsic immunological differences and/or responses between individuals, can significantly affect the outcome of these tests. Recently, some commercially available immunoassays received CE Mark for professional use (Shenzhen profitable moving average forex strategies Bioeasy Biotechnology, n.d.; Diagnostics, 2020), and therefore are registered as in vitro diagnostic devices. Coronaviruses are an extensive family of viruses that can cause disease in both animals and humans. The current classification of coronaviruses recognizes 39 species in 27 subgenera that belong to the family Coronaviridae.

Routine use of corticosteroids has been discouraged, and restricting it exceptionally for patients who develop ARDS, although without reports of improvement in survival, with discrepancy in results of shorter mechanical ventilation time and ICU stay (Wang et al., 2020c). For patients with advanced cancer, the main approach should be to minimize hospitalization in COVID-19 positive installations. Replacing the existing intravenous treatment regimen with oral chemotherapy during this special period may be considered, to ensure that treatment is not interrupted for a long time during the pandemic (Binliang et al., 2020).

Table 6

Progressive deterioration of respiratory function is undoubtedly the most common and life-threatening complication of the infection. The prevalence of hypoxic respiratory failure in COVID-19 patients is 19%, and it can progress to acute respiratory distress syndrome , with the need of mechanical ventilation support at 10.5 days on average. One study found that between 10 and 32% of hospitalized patients require admission to the ICU due to respiratory deterioration (Murthy et al., 2020). As respiratory complications are the most common cause of severe deterioration, early identification of them will undoubtedly help in timely support.

When specific humidity drops below 11–12 g/kg and temperature drops below 18–21°C, the peak of influenza is stimulated during the cold-dry season, however, for tropical and subtropical regions, it is likely to prevail during the high precipitation (≥150 mm) months (Tamerius et al., 2013). The “cold-dry” set of climatic conditions endorses a greater survival of the virus outside human body, and, thus, results in better transmission (Lofgren et al., 2007; Lowen and Steel, 2014). Laboratory experiments testing virus stability, demonstrated a decreasing infectivity with increasing ambient temperatures, where at 4°C, 56°C and 75°C the survival rates outside host decreased from at least 96 to 1.5 and to 0.5 hours, respectively (Duan et al., 2003). In addition, cold air cools nasal epithelium which, in turn, decreases mechanical defenses of the respiratory and immune systems . Currently there are no approved vaccines against any human coronavirus, suggesting that their generation is quite novel.

10. Diagnosis methods to detect COVID-19

On the other hand, there are reports of cases without overt symptoms in which there were ground glass images in the chest tomography in up to 50% of patients (Shen et al., 2015). Most of the tests enlisted in this review are currently available for use under a EUA by the FDA, a policy that aims to quicken the approval process for US labs developing tests for COVID-19. The approval is part of a concerted effort to make up for a lost time after delays and then a global shortage of the essential chemicals needed to make new tests . Some companies have developed high-throughput equipment that automates sample RNA extraction, PCR assembly, and detection, thus avoiding some bottlenecks during the processing of samples mainly caused by the unavailability of reagents, consumables, and the lack of trained staff. For example, Xpert® Xpress SARS-CoV-2 is designed for use on Cepheid’s GeneXpert® Systems that allows the addition of the patient’s sample on cartridges where RNA extraction and PCR are carried out, allowing rapid diagnosis of large numbers of cases (AvellinoCoV2 Test, n.d.). On January 11, the first SARS CoV-2 related death was reported and 1 day later, a group of Chinese researchers revealed the genome of the virus implicated in the Wuhan pneumonia outbreak.

Based on the clinical scenarios described, there has also been no impact of viral load or CD4 + cell count on the risk of contracting COVID-19 and/or developing serious complications. It is important to notice that, if dyspnea is an important clinical finding, not all the patients with this symptom will develop severe respiratory distress or require oxygen supplementation (Wang et al., 2020a). It has been shown that in severe cases both SARS-CoV and MERS-CoV teletrade metatrader 4 fruitfully employ an immune evasion mechanism whereby early type I IFN responses to viral infection are dampened . This can be achieved by blocking signaling both upstream, as well as downstream of type I IFN expression. SARS-CoV can inhibit IRF3 nuclear translocation, whereas MERS-CoV can impede histone modification (Kindler et al., 2016). Additionally, both viruses can inhibit IFN signaling by decreasing STAT1 phosphorylation (de Wit et al., 2016).

The international average mortality is 3%, although there is a difference between countries depending on the average age, the ascending curve, the method used to register COVID-19, and the health services, especially ICU units. In Spain at the time of writing mortality is 67% in patients over 80 years, 20% in those aged between 70 and 79 years and 8% between 60 and 69 years. It is important to note that if identification of cases was universal across all the population, these figures may vary considerably. It is vital that reliable, comparable data is available internationally, to facilitate comparison of mortality data in Italy, Spain and other countries such as Germany or the USA (Fig. 2). According to WHO, the recovery time is estimated to be 2 weeks for patients with mild infections and 3 to 6 weeks for those with serious illnesses. On the other hand, CDC established that people who had symptoms in the mild to moderate spectrum and maintained home isolation have a resolution of 3 days after the fever decrease, and there was a substantial improvement in respiratory symptoms, even without use of medications.

Li Z., Yi Y., Luo X., Xiong N., Liu Y., Li S. Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis. Li W., Moore M.J., Vasllieva N., Sui J., Wong S.K., Berne M.A. Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus. Huang C., Wang Y., Li X., Ren L., Zhao J., Hu Y. Clinical features of patients infected with 2019 Novel Coronavirus in Wuhan. Huang C., Wang Y., Li X., Ren L., Zhao J., Hu Y. Clinical features of patients infected with 2019 Novel Coronavirus in Wuhan, China. Gu H., Xie Z., Li T., Zhang S., Lai C., Zhu P. Angiotensin-converting enzyme 2 inhibits lung injury induced by respiratory syncytial virus.

Table 4

With information obtained so far from the Wuhan SARS-CoV-2 outbreak, the infection appears to be less severe for pregnant women, compared to previous SARS-CoV and MERS-CoV outbreaks . However, it is important to take into account that the data obtained are from reviews consist of a small number of patients. Additionally, the majority of pregnancies with confirmed SARS-Cov-2 pneumonia were in the third trimester and there were very few within the first and second trimesters. Therefore, more information should be collected with larger numbers of pregnant women with the infection. Follow-up of positively diagnosed pregnant women during in the first and second trimesters should be encouraged, to understand the impact of the new coronavirus infection on the pregnant mother, the fetus and the course of pregnancy (Chen et al., 2020c).

Bordi L., Nicastri E., Scorzolini L., Di Caro A., Capobianchi M.R., Castilletti C. Differential diagnosis of illness in patients under investigation for the Novel Coronavirus (SARS-CoV-2), Italy, February 2020. Baruah V., Bose S. Immunoinformatics-aided identification of T cell and B cell epitopes in the surface glycoprotein of 2019-nCoV. While low winds might improve its transmission from one host to another, strong winds contribute to its dispersion and ventilation (Xiao et al., 2013), which could be a positive effect depending on wind direction. Huge challenges need to be tackled in order to minimize the long and cumbersome process of vaccine generation.

• The evidence about the transmission of the virus in the asymptomatic period also changed the containment measures, suggesting the community use of masks.
• Even though COVID-19 can be diagnosed using qPCR as the gold standard, inadequate access to reagents and equipment has slowed disease detection even in developed countries such as the US.
• In contrast, bacterial coinfection was infrequent (Bordi et al., 2020; Corman et al., 2020b).
• This extensive and comprehensive literature review tries to offer a good insight of the most recent information available.
• Tregs form the T cell subset responsible for controlling excessive inflammatory responses and their absence can lead to production of cytokine storm and enhancement of tissue pathology.

The descriptive studies available so far have concluded that the majority of cases are mild infections (more than 80% of cases); with up to 15% of patients being sever in most cohorts, and less than 5% have been considered as critical cases with high vital risk (Medical Association A., 2019). The basic reproduction number is a measure that quantifies the epidemic potential of a pathogen. This number is defined as the average number of persons an infected person can spread the virus. Based on standard epidemics, having R0 greater than 1 could lead to potential spread of diseases.

5. SARS CoV-2 and human immune responses

Variables such as skin temperature, capillary refill time and/or serum lactate measurement are currently valid tools to assess shock. The volume of liquids used in resuscitation should be restricted and administered in relation to dynamic assessment. A liberal water resuscitation strategy is not recommended, rather a balance of crystalloids over colloids as resuscitation liquids should be encouraged and avoiding the use of hydroxyethyl starches, albumin, dextrans or gelatins (Silversides et al., 2017; Lewis et al., 2018). Indirect evidence suggests that the target mean arterial pressure for patients with septic shock is 65 mmHg using vasoactive support (Lamontagne et al., 2020). If norepinephrine is unavailable, vasopressin or epinephrine could be used, avoiding the use of dopamine as the initial vasopressor due to the potential development of arrhythmias (Gamper et al., 2016; Møller et al., 2018).

Table 2

Among them, candidate antigen targets need to be identified, immunization routes and delivery systems investigated, animal models set, adjuvants optimized, scalability and production facility considered, target population selected, and vaccine safety and long-term efficiency evaluated. The evolution of the epidemiological curve in COVID-19 outbreak makes consider containment strategies in China primarily, and other countries based on non-pharmaceutical interventions . Isolation may be limited to 7 days from resolution of symptoms, however, it must be adapted to the population circumstances of the epidemic (Guan et al., 2020a). However, if there is a suspicion of COVID-19 infection in this population group, the same updated diagnostic guidelines and the corresponding management should be followed depending on their severity of illness. Moreover, an individualized follow-up plan should be outlined due to higher likelihood of complications in this group of population (Jazieh et al., 2020). It is important to mention that coinfection is a possibility, as some reports from Italy and China had described.

Numbers of CD8+ T lymphocytic cells responsible for recognizing and killing infected cells were found to be significantly lower in patients with severe manifestations of COVID-19. Additionally, severely affected patients presented with a higher naïve CD4+ to memory T cells ratio, suggesting that the adaptive immune system in the severe infection subgroup was less activated. Furthermore, these patients had less numbers of regulatory T cells , especially induced Tregs. Tregs form the T cell subset responsible for controlling excessive inflammatory responses and their absence can lead to production of cytokine storm and enhancement of tissue pathology.

Hoffmann M., Kleine-Weber H., Schroeder S., Krüger N., Herrler T., Erichsen S. SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor. He X., Lau E.H., Wu P., Deng X., Wang J., Hao X. Temporal dynamics in viral shedding and transmissibility of COVID-19. Feng S., Shen C., Xia N., Song W., Fan M., Cowling B.J. Rational use of face masks in the COVID-19 pandemic. Favre G., Pomar L., Qi X., Nielsen-Saines K., Musso D., Baud D. Guidelines for pregnant women with suspected SARS-CoV-2 infection. Corman V.M., Landt O., Kaiser M., Molenkamp R., Meijer A., Chu D.K. Detection of 2019 Novel Coronavirus (2019-nCoV) by real-time RT-PCR. Chavez-MacGregor M., Clarke C.A., Lichtensztajn D.Y., Giordano S.H. Delayed initiation of adjuvant chemotherapy among patients with breast cancer.

Regarding to the discovered imbalance in the expression of INF-1 of the virus-host interaction, INF acts like a protector, if is applied early in SARS infection (Spiegel et al., 2004). The investigations propose combinations of pharmacological interventions of Interferon alone and in combination with lopinavir / ritonavir . In general, there is no clinical evidence in humans on the action of INF in SARS and MERS Coronavirus infections. Supportive therapies in immune regulation, together with the use of antivirals, are important to take into account, especially in those patients in a serious and critical state, in which they could improve the clinical response and perhaps avoid residual lung injuries. Interferon is a biological antineoplastic drug, used to treat multiple hematologic malignancies and skin diseases.

In patients who are asymptomatic, home management is acceptable on the proviso they should seek further medical advice if their symptoms develop into more severe disease. All mothers recovering from COVID-19 infection should be monitored with a Doppler ultrasound every 2 weeks, due to the risk of developing intrauterine growth restriction (Favre et al., 2020; Rasmussen et al., 2020). Some of the guidance related to the effects of the coronavirus in pregnant women and the fetus is due to previous studies of various viruses. During the SARS-CoV pandemic in 2002 and 2003, in a very small study of 12 patients, women infected during their first trimester had high a miscarriage rate (57%).

These data suggest that vaccine strategies employing viral structural proteins that can elicit effective, long-term memory T cell responses could yield fruitful results. Delayed type I IFN production allows for highly efficient viral replication that, in turn, results in recruitment of hyperinflammatory neutrophils currency strength indicator and monocytes. Therefore, the pathogen recognition receptors of these proinflammatory cells recognize high numbers of their ligands and subsequently secrete excessive amounts of proinflammatory cytokines that lead to septic shock, lung pathology, pneumonia or acute respiratory distress syndrome.

The effect of chloroquine, hydroxychloroquine and azithromycin on the corrected QT interval in patients with SARS-CoV-2 infection. Hoffmann M., Kleine-Weber H., Schroeder S., Mü M.A., Drosten C., Pö S. SARS-CoV-2 Cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor article SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor. Duan S.-M., Zhao X.-S., Wen R.-F., Huang J.-J., Pi G.-H., Zhang S.-X. Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation. Dong E., Du H., Gardner L. An interactive web-based dashboard to track COVID-19 in real time. Broughton J.P., Deng X., Yu G., Fasching C.L., Singh J., Streithorst J. Rapid detection of 2019 Novel Coronavirus SARS-CoV-2 using a CRISPR-based DETECTR lateral flow assay.

Three recent examples of these viral jumps include SARS CoV, MERS-CoV and SARS CoV-2 virus. They are responsible for causing severe acute respiratory syndrome , Middle East respiratory syndrome and the most recently discovered coronavirus disease during 2019 (COVID-19). Classic vaccine strategies like use of attenuated virus or recombinant protein subunit administration begin to lose support in the scientific community. COVID-19 mainly affects older patients with underlying pathologies that debilitate their immune system. Use of attenuated virus vaccines is contraindicated in these populations as weakened immune systems can permit the reversion of the attenuated pathogen to its wild type state, therefore causing the pathology it was designed to prevent. On the other hand, subunit vaccine design can be challenging when the protein used contains extended glycosylation.

Xu H., Zhong L., Deng J., Peng J., Dan H., Zeng X. High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa. Wu C., Liu Y., Yang Y., Zhang P., Zhong W., Wang Y. Analysis of therapeutic targets for SARS-CoV-2 and discovery of potential drugs by computational methods. Perera R.S., Ding X.C., Tully F., Oliver J., Bright N., Bell D. Development and clinical performance of high throughput loop-mediated isothermal amplification for detection of malaria. Ortiz-Prado E., Diaz A.M., Barreto A., Moyano C., Arcos V., Vasconez-Gonzalez E. Epidemiological, socio-demographic and clinical features of the early phase of the COVID-19 epidemic in Ecuador. Nicolaides C., Avraam D., Cueto-Felgueroso L., González M.C., Juanes R. Hand-hygiene mitigation strategies against global disease spreading through the air transportation network.

Associated Data

In-fact one sign of infection of COIVD-19 is a symptom of anosmia in asymptomatic patients without nasal obstruction. Additionally, patient can transmit the infection up to 2 weeks after having recovered from symptoms of the disease. At the beginning of the outbreak it started to move through Asia but only days later the first suspicious cases were reported in Europe and North America.

During their second and third trimesters they developed intrauterine growth restriction (40%), and preterm delivery (80% ), and 3 women died during pregnancy (25%) (Wong et al., 2004b). In another study of 11 pregnant patients infected with MERS-CoV, 9 presented adverse results (91%), 6 neonates were admitted to the neonatal intensive care unit (55%) and 3 of them died (27%) (Alfaraj et al., 2019). However, it is important to note the small sample size which could increase the risk of bias and low power of the study. Production of protective antiviral antibodies and long-lived memory B cells are fundamental for avoiding reinfection with the virus and form the basic principles behind vaccination.