A Review on Epidemiology, Emergence, Spread, Clinical Aspects, Avoidance and Management of COVID-19 Outbreak

Mahdi Mohammed Alrajhi¹ and Naif Albaqami^2*

^*Correspondence: Naif Albaqami, Medical Director, Family Medicine Senior Registrar, Comprehensive Specialized Clinic in Public Security Training City, Kingdom of Saudi Arabia, Email:

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Introduction

COVID-19 attracted the attention of the world from its commencement in Wuhan, China. The Respiratory ailment has been observed as the primary assail of the virus. It has been affirmed as a public health crisis by the WHO i.e., World Health Organization. According to the WHO, this virus makes up a hefty cluster of viruses that is capable to contaminate mammals, birds, and even humans. These viruses are accountable for numerous eruptions around the globe, counting 2015 and 2003 pandemics of Middle East Respiratory Syndrome and Severe Acute Respiratory Syndrome respectively [1,2]. COVID-19 generated an outburst in China in December 2019, embarking worldwide apprehension and distress. Though some corona viruses have originated upsetting epidemics in the past, others have caused mild to moderate respiratory contagion like common cold [3-6].

Epidemiology and Prevalance

According to the data recollected from one of the most hit areas of the virus in Hubei, China, a total of 81% of incidences were categorized as placid, 14 as stern and 5% were categorized as severe. The comprehensive rate of fatality was observed as 2.3%; though, in cases aging between 70–80 years, the fatality rate was 8.0% to 14.8%, respectively [7,8]. This data brings out significant statics. The devastating effect of the virus was prominent in elderly males with some chronic ailments like diabetes, depression, heart disease, etc [9]. The contagion of the virus is conveyed through droplets produced at the time of sneezing or coughing, by indicatives although it can happen from persons to show no symptoms at all [10]. Researches have revealed elevated viral loads of the virus in the nasal tract as matched up to the throat with no distinction in viral load amidst the indicative and nonindicative people [11,12]. The disease could be contagious until the indications are shown and yet on medical recuperation. Some could even operate as a super transmitter. Such cases might infect a good number of people in a truly short span [13].

As stated, the droplets of the diseased caused by coughing or sneezing can extend up to two meters on the surface and deposit there. The virus there can stay feasible on the surface for days in appropriate circumstances. However, they can be shattered in a few seconds as well by applying disinfectants like hydrogen peroxide, sodium hypochlorite etc [14]. Contamination is attained either by the intake of such droplets through inhalation or having contact with contaminated surfaces. Contact of these droplets to eyes, nose, or mouth infects a person by transmitting the virus in the body.

Origin and Spread of Infection

Some patients reported to the hospital in December 2019 Wuhan, China. They all had a common problem like severe pneumonia. The administration was on the toes after the disclosure of a fact that all had one thing in common and that was their visit to the Huanan wholesale seafood market in the province. The observations were made on an urgent basis and respiratory tasters of such cases were sent to the labs for investigations. In the last week of December 2019, China released an alert of an outbreak of virus to the WHO, the World Health Organization.

The scrutiny of community genome succession data from SARS-CoV-2 and allied viruses is attempting to find the ground of origin of the virus. However, studies conducted so far indicate that the bats are the innate owner of SARSCoV- 2, and snakes pangolins are the transitional hosts. Research from Peking University recommended that COVID-19 contamination is in all probability is caused by snakes [15-19], though there is a varied opinion about this. Research from Wuhan Institute of Virology displayed 96.2% resemblance in the gene succession amidst SARSCoV- 2 and bat corona virus with succession expertise [20]. This inferred that bats are the probable cause of COVID-19. Pangolins too are the possible intermediary host of SARS-CoV-2. Though no work to date has completely expounded the latent biological host and intermediary host of SARS-CoV-2. The number of cases started rising at a swift speed. People having no direct approach to the market are indicative of the fact that human-to-human spread was happening. The primary deadly incident was accounted for on 11^th Jan 2020 [21] (Table 1 and Figure 1).

Table 1: Daily incidence of Covid-19 as on 2020-05-19. (Source: https://www.worldometers.info/coronavirus/).

Figure 1. Total Active cases deaths as on 2020-06-1.

Molecular basics of transmission of coronavirus

Chinese researchers tested 33 samples containing SARSCoV- 2 on January 1^st,2020, and pointed to the fact that it sourced from animals sold in the market [22]. Later, they used blood, fluid of the lung, and a swab of throat samples of fifteen sufferers to perform tests. These investigations established the fact that the virus-centric nucleic acid successions in the taster are dissimilar from those of recognized human corona virus species. Laboratory outcomes besides pointed that SARS-CoV- 2 is akin to some of the beta (ß) corona viruses genera recognized in bats [23-25]. The upshots of nextgeneration sequencing pointed that SARS-CoV-2 was far remote from SARS-CoV and MERS-CoV than from two bat-derived SARS-like corona viruses [26,27]. Researches also accounted that COVID-19 S-protein sustained brawny interface with human ACE2 molecules despite the distinction of its success with that of SARS-CoV28. Many domestic and wild animals can serve as hosts for coronaviruses. They include bats, camels, cats, and [25], it is measured that, usually, animal corona viruses do not reach among humans [28]. Though exceptions cannot be denied at the same time. At the time when a virus goes into the body, it combines the prime target cells such as pneumocytes and enterocytes thus creating a sequence of contagion and reproduction [22,23]. There are other target cells of CoV too which are epithelial renal tubules, immune cells, tubular epithelial cells of the kidney and cerebral neuronal cells [25].

Symptoms

Preliminary symptoms of COVID-19 infection are very usual. They can be attached to the common symptoms of cold or flu-like symptoms. They are at first mild. Though, as per the resistant capacity and individual type, the symptoms may vary. The usual symptoms are:

Cough.

Exacerbated asthma.

Fever in rare cases.

Runny nose.

Sneezing.

Sore throat.

Watery diarrhoea [36,37].

Management of Covid-19

RT-PCR has turned out to be the system of selection for the investigation of human CoV. They are capable to perceive all respiratory HCoVs and can be additionally personalized to novel CoVs. Serologic examinations are central in cases where RNA may be complicated to separate [38-40]. No anti-viral therapeutics are available to date that particularly targets human coronaviruses. A cure is merely helpful. Belligerent loneliness methods in China have emerged to a progressive decrease in incidences. Though it may have grounds for discussions and arguments on some platforms. Health authorities in Italy are making implausible labors to hold the pandemic that is ruthlessly testing the health system of the nation [41-43]. The WHO released a document on January 28, 2020, briefing its course of action and scientific proofs taken from the cure of earlier epidemic instances from HCoVs. Some of them are as follows:

Intubation and protective mechanical ventilation

Extraordinary safety measure is compulsory at the time of intubation. The method should be carried out by a professional hand who uses PPEs like FFP3 or N95 mask, shielding goggles, disposable double socks, and gown with long sleeve raincoat and gloves. If feasible, rapid sequence intubation (RSI) should be performed. Preoxygenation (100% O2 for 5 minutes) should be practiced via unremitting affirmative airway pressure technique. Heat and moisture exchanger (HME) must be placed between the mask and the circuit of the fan. Furthermore, extrication from the ventilator must be let alone for averting loss of PEEP and atelectasis [44].

Non-invasive ventilation

The expert's panel, concerning the HFNO or non-invasive ventilation, indicates that the measures executed by a system with good interface connection do not generate extensive scattering of puffed-out air and their exercise could be measured at squat peril of airborne spread. Non-invasive practices can be executed in the non-critical appearance of respiratory breakdown. Though, if the situation does not get better or even deteriorate in a petite epoch of instance, the motorized airing must be favoured [45].

Other strategies

It has been suggested to apply suitable indicative healing and encouraging care46 concerning to the patients infected with COVID-19. There are six medical trials to assess the effectiveness of the protection of aimed medicine in the cure or forecast of COVID-1947. It has been also suggested in terms of contaminated patients with COVID-19 to relate opposite symptomatic healing and compassionate care [46-48]. Researches have also discovered the deterrence of nosocomial contamination and psychological wellbeing concerns related to COVID-19. A succession of effective methods has been recommended to diminish nosocomial contamination, together with information guidance for preclusion and management, disinfection, seclusion, confidential defenses at diverse degrees in diseased spots, and guard of established affirmative cases [49]. On the psychological wellbeing, there are advisories for positive cases, suspects and medical and frontline staff [50]. Since there is no vaccine for the virus so far, the best way to stay safe is to avoid contact with the virus [51].

Here are some precautionary measures:

Avoidance to public areas.

Avoiding smoking.

Consuming only thoroughly cooking meat, eggs, or vegetables.

Covering mouth and nose while coughing and sneezing.

Customary hand washing.

Intake of enough water.

Keeping social distance.

Proper physical rest and psychological relaxation.

Using a fresh humidifier or cool mist vaporizer.

Conclusion

COVID-19 is a lethal virus. A discussed in the article, there is no recommended vaccine for the virus so far. In that case, it is advisable to follow safety measures and be cautious of the symptoms stated. However, researches are being made in various locations of the world and the expectations of mankind are extremely high for an acute vaccine of this deadly virus.

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