SARS-CoV-2 Infection and Coronavirus Disease (COVID-19) Clinical Data: A Review of the Literature

1School of Medicine, University of Celaya, Celaya, México, CP 38080. 2Department of Nursing and Obstetrics, Division of Health Sciences and Engineering, Campus Celaya-Salvatierra, University of Guanajuato, Celaya, México, CP 38060. 3Clinical Nursing, Division of Health Sciences and Engineering, Campus Celaya-Salvatierra, University of Guanajuato, Celaya, México, CP 38140. 4Institute of Public Health from Guanajuato State, Guanajuato, México CP36,000. *Corresponding Author E-mail: npadilla@udec.edu.mx

Since December 8, 2019, several cases of pneumonia were reported in Wuhan, Hubei Province, China 1 and it was reported to the World Health Organization (WHO) office on December 31 of the same year 2 . Several of those patients worked at the Huanan seafood market and a virus was isolated from a patient's throat, which was named 2019-nCoV by WHO and later SARS-CoV-2 3 . Because the increase in cases, in one month, the WHO declared a Public Health emergency of international interest on January 30, 2020 2 .
The pandemic has spread practically worldwide with more than 200 countries where cases have been confirmed; As of March 30, 2020, 693, 282 confirmed cases, and 33,106 deaths have been reported worldwide 4 .

SARS-CoV-2
Human coronaviruses belong to the order Nidovirales, family Coronaviridae, and genus Alphacoronavirus or Betacoronavirus, called SARS-CoV-2, can cause coronavirus-19 disease (COVID-19); the virus is highly infectious, the entire population is susceptible, and person-toperson contact, as well as drops expelled when coughing or sneezing, are the main routes of transmission 5,6 .
Aerosol particles may be another source of transmission and there is no evidence of vertical mother-product transmission 7 . Coronaviruses are enveloped non-segmented positive-sense RNA 8 .
After one month from the presentation of the initial case, the virus was isolated, its genome was sequenced and its morphology was described and the sequence was shared with the WHO 9 .
SARS-CoV-2, which causes COVID-19, uses the same input receptor, angiotensinconverting enzyme 2, as SARS-CoV, which is expressed in airway epithelial cells; It is the seventh member of the coronavirus family that infect humans and has higher infectivity than SARS-SoV or MERS-CoV, since SARS-CoV-2, grows better in epithelial cells of the respiratory tract 10 .
The main objective is to describe the signs and symptoms reported to COVID-19, since it is the first way to categorize patients in areas of first level of care.

MethodS
A search of articles was carried out, with the words of Clinical data, signs and symptoms, COVID-19, Coronavirus, in Spanish and English in Pubmed, Web of Knolwedge, Scopus, Google Schoolar, between 23-25 March 2020. In the first instance, itdid obtained 2,544 articles, of which those that did not describe the clinical data of COVID-19 were discarded.
Three articles were selected that describe the clinical data of SARS-CoV-2 infection; 5 articles were selected that describe the clinical data of pneumonia caused by SARS-CoV-2; and it did selected 1 article that describes olfactory dysfunction in patients with COVID-19, and 1 editorial that describes the clinical data in children with COVID-19.

ReSultS
The team reviewed the articles, and selected3 of them with description of clinical data of COVID-19 (Table 1). Table 2 show the signs and symptoms reported in the 2 articles [11][12][13] .
In a series of 9 pregnant women, reported in Wuhan China, they show clinical data on pregnant women infected with SARS-CoV-2 11 .  Liu et al. 12 studied 44 patients and reported practically the same clinical data as other studies 11,13 . Guan et al. 13 , studied 926 cases.
Olfactory and gustatory disorders have been reported in patients with COVID-19 described byReza Bagheri et al. 17 , in Iran in March 2020, where they describe the correlation between olfactory dysfunction and COVID-19. More cases with smell disorders need to be identified among the confirmed cases of COVID-19.Accord to Russell et al. 18 there is currently no published evidence or case reports noting anosmia and/or ageusia/dysgeusia in COVID-19 patients.
And, specifically in children, an editorial was found describing the clinical data of 171 infected children with ages from less than 1 to 15 years old, men predominated (60.8%) and Table 6 shows the reported clinical data, being the cough was more frequent, where they reported 15.8% asymptomatic infection, Upper respiratory tract infection (19.3%) and pneumonia (64.9%) 19 .

dISCuSIoN
With these reports and a total sample of 1,283 cases of COVID-19, the most frequent clinical data were fever (90.4%), cough (62.2%) and expectoration (23.2%) (Table 3) The clinical data of confirmed COVID-19 patients, is the first line of classification to decide whether to apply the diagnostic test to detect SARS-CoV-2. And it is important to highlight that a suspicious case was that with dry cough and in the clinical pictures in China, they show that around 26% had expectoration production (Table 3) and could leave many people without performing the PCR for detection of SARS-CoV-2.
The importance of the pandemic is such that it has exceeded the capacities of the health systems even in developed countries and with greater amounts of financial and technological resources. In Mexico, the first line of classification of patients is the clinical picture, according to the guidelines generated by the Ministry of Health and published by the General Directorate of Epidemiology on March 17, 2020 20 .
According to them, suspicious cases are those with fever and / or cough and who at least have dyspnoea or myoarthralgia, headache, odynophagia and have had contact with a case or have travelled to a high-risk country. A confirmed case is a suspected case that tested positive for SARS-CoV-2 in laboratories of the National Network of Public Health Laboratorieswith Real Time-Polymerase Chain Reaction (RT-PCR) 20 .
This classification for testing may exclude asymptomatic carriers, and they are important for the spread of infection, despite measures taken by country governments such as suspension of non-essential activities, social isolation, and other preventive measures such as hand hygiene and healthy distance.
Regarding the clinical picture reported for cases with SARS-CoV-2 pneumonia, the most frequent was fever (77.4%), cough (68.9%) and myoarthralgia (49.9%) ( Table 5).But these clinical data are not different from another pneumonia of viral or bactericidal origin Comparing the clinical pictures of SARS-CoV-2 infection and SARS-CoV-2 pneumonia are similarbut there are not difference with another upper respiratory tract viral infections or pneumonia from viral or microbe origin.
In children, the clinical data of 171 children were reported 19 (Table 6) and the clinical picture is similar to that of adults with fever and cough, adding pharyngeal erythema.

CoNCluSIoN
The clinical data from COVID-19 are common in upper respiratory tract viral infections different to SARS-CoV-2 infection.
Pneumonia by SARS-CoV-2 show the same clinical data that another viral or bacterial pneumonia.
It is not to be trusted to establish only with a clinical picture whether or not the test is done according to a comprehensive assessment.