Introduction to coronavirus essay

At first, We should note that coronaviruses are one of the most important factors targeting respiratory systems in humans. Coronaviruses are enveloped +ssRNA viruses and it is the largest RNA genome, The name of this group of viruses “corona” came from its distinctive shape (a crown-like shape with projections at the surface). This includes previous coronavirus outbreaks:

• Severe acute respiratory syndrome coronavirus (SARS)-CoV: It started in China in 2002 and spread to several countries, but after two years from 2004 to today no new cases have been registered.

2- Middle east respiratory syndrome (MERS): The first report was in Saudi Arabia in 2012 that spread to other countries, especially in the countries of the Middle East [1].

Now a new coronavirus has appeared since  18 December last year 2019 to today it has been called (SARS-CoV-2) which we will mention details about it until today in this review (its origin, pathogenesis, clinical manifestations, diagnosis of the disease, vaccines with treatment, control and prevention).

Many severe acute respiratory syndrome cases began to appear at the end of last December in 2019 in China, Hubei Province, the city of Wuhan. Initially, a small number of cases of unknown pulmonary infections were recorded [2], but with the misconceptions that the virus does not spread directly between patients and from one person to another (the new virus was considered not to be very widespread and this is the biggest mistake).

After that, the number of cases increased very dramatically to reach thousands of injuries within several months and the virus invaded the world dramatically, which lead to the closure of airspaces in many countries in an attempt to prevent outbreaks of the virus more than what happened. Was considered  the cause of these (unexplained) pulmonary infections to be a new coronavirus called COVID-19 [3].

The number of patients with Covid-19 in December was only 5 patients and the increase continued slowly until the beginning of the year 2020. At the end of January, there was a report indicating that there were 7,734 confirmed cases in China only and that Covid-19 had spread to 90 other countries around the world which was Taiwan, Thailand, Vietnam, Malaysia, Nepal, Sri Lanka, Cambodia, Japan, Singapore, Republic of Korea, United Arab Emirates, United States, Philippines, India, Australia, Canada, Finland, France, and Germany.

It was later discovered that the new coronavirus is rapidly spreading after a large number of infections were recorded as more than 80,000 confirmed infections were recorded in China only until 23-3-2020 [4]. This virus is considered a major health threat worldwide. To this day, about 6 million confirmed infections have been recorded in 215 countries around the world, most of which were in the United States of America, European Union countries, Iran, India, Peru, China, and Canada. More than 350,000 deaths have been recorded, compared to 2.4 million fully recovered from Covid-19 [5].

In China, a large number of people diagnosed with Covid-19 were linked to their exposure to the wet animal market in Wuhan, a place where animals are normally sold. It is believed that the zoonotic origin of COVID-19 is through this market as some initial reports have identified two types of snakes that could be a potential reservoir for Covid-19. Later reports showed that the new coronavirus could be transmitted through humans through direct contact or contact with drops outside the cough of an infected person [4].

The problem is that there is a possibility of transmission of infection through people who do not show symptoms or people during the incubation period of the new coronavirus and this is new in human history in infectious diseases that was not recorded previously. This lead to serious challenges in controlling and preventing infectious diseases.

The clinical symptoms range from one without any symptoms to severe respiratory distress syndrome. Common symptoms include fever (not found in all patients), cough, sore throat, headache, muscle pain, and shortness of breath. By the end of the first week, the disease can develop and leads to pneumonia, respiratory failure, and finally death [7].

Here we must mention that the main cause of death is shortness of breath, pneumonia, and the complications that follow. The new coronavirus targets the respiratory system and its internal organs, and this can be seen through symptoms associated with the disease, such as coughing, sneezing, and sore throat. In some patients, these symptoms may develop into a lung infiltration that causes shortness of breath and lack of oxygenation in the patients’ bodies. As we mentioned earlier, these respiratory failure leads to death in the end.

We can say that the onset of symptoms is the beginning of the diagnosis, especially when combined with a previous history of travel to places where the disease has spread, such as China and America. And then some tests are done until the infection is confirmed, such as the general blood cell count and the most important analysis, PCR, which is currently approved internationally.

Male and female patients were close, there was no significant difference in the number of patients, however, the number of male deaths was 61.8%, while the number of female deaths was 38.2%, according to a new report published a while ago [6]. The most common deaths were among the elderly and those suffering from concomitant diseases such as diabetes and various cancer cases (50-75% fatal cases).The death rate among adult patients in hospitals was 4% to 11%, depending on the location and the rate of disease spread in the region [5].

As for the situation in Egypt, the infection rates are still increasing. Unfortunately, this increase was at a great rate to reach more than 700 daily infections last week. The total number of infections with Covid-19 reached more than 20 thousand, bearing in mind that the death rate is about 5% of the total number of injured, with 5,000 cases fully recovered.

There were reports that the disease in children, infants, and newborns was significantly milder than in adult patients. A report from China explains that all the patients of the children were without symptoms or with mild symptoms and there were no serious cases between this group of patients and all the patients recovered by treating their symptoms and no deaths were recorded among them. Only one case of children suffered from acute pneumonia and failure of some organs [10].

Concerning treatment, it is basically a supportive or reduced symptomatic treatment and of course, the first step with this global pandemic disease is to isolate confirmed cases and ensure safe isolation to prevent transmission between people and between medical staff in isolation places and hospitals (the first doctor who warned of the disease died due to infection With virus). It should be mentioned here that as of the date of writing this research there has been no specific treatment for Covid-19 and antivirals have been used based on previous experiences with SARS and MERS. Because there is no specific treatment intended until today, prevention and control of the disease is very necessary.
Therefore, the focus should be on caring for general hygiene while increasing awareness among people about the importance of washing hands for no less than 20 seconds with soap or ethyl alcohol with a concentration of 70%. In addition to the need to use personal protection methods and the importance of their availability, especially when dealing with suspected cases at home or among care health workers.

There are no vaccines approved until today, but there is a lot of ongoing research every day with a lot of tests on the effectiveness of experimental vaccines in a large number of countries that strive to produce a vaccine as soon as possible.

References:
1. Staff members of medial microbiology and immunology department. Essential medical microbiology and immunology. (7th ed.). Egypt: 2019.

2. Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, Ren R, Leung KS, Lau EH, Wong JY, Xing X. Early transmission dynamics in Wuhan, China, of novel coronavirus–infected pneumonia. New England Journal of Medicine. 2020 Jan 29.
3. Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P. A novel coronavirus from patients with pneumonia in China, 2019. New England Journal of Medicine. 2020 Jan 24.
4. Rothan HA, Byrareddy SN. The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. Journal of autoimmunity. 2020 Feb 26:102433.
5. Coronavirus Outbreak. Available at: https://www.worldometers.info/coronavirus/.
6. New York City Health Daily data summary in April 14, 2020.
7. Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, Qiu Y, Wang J, Liu Y, Wei Y, Yu T. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. The Lancet. 2020 Feb 15;395(10223):507-13.
8. Xu XW, Wu XX, Jiang XG, Xu KJ, Ying LJ, Ma CL, Li SB, Wang HY, Zhang S, Gao HN, Sheng JF. Clinical findings in a group of patients infected with the 2019 novel coronavirus (SARS-Cov-2) outside of Wuhan, China: retrospective case series. bmj. 2020 Feb 19;368.
9. Cheng ZJ, Shan J. 2019 novel coronavirus: where we are and what we know. Infection. 2020:1–9. 10.1007/s15010-020-01401-y. 2020 Feb 18.
10. Chen F, Liu Z, Zhang FR, Xiong RH, Chen Y, Cheng XF, Wang WY, Ren J. First case of severe childhood novel coronavirus pneumonia in China. Zhonghua er ke za zhi= Chinese journal of pediatrics. 2020 Feb 11;58:E005.
11. Singhal T. A review of coronavirus disease-2019 (COVID-19). The Indian Journal of Pediatrics. 2020 Mar 13:1-6.