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Review
Res Rev Biosci, Volume: 15( 2) DOI: 10.21767/0974-7532.1000153

COVID-19: Morphology, Characteristics, Symptoms, Prevention, Clinical Diagnosis and Current Scenario

*Correspondence:
Mukesh Meena
Department of Botany
Mohanlal Sukhadia University
Udaipur, Rajasthan, India
Tel: +91- 9667720689
E-Mail: [email protected]

Received: May 16, 2020; Accepted: June 1, 2020; Published: June 8, 2020

Citation: Barupal T, Tak PK, Meena M. COVID-19: Morphology, Characteristics, Symptoms, Prevention, Clinical Diagnosis and Current Scenario. Res Rev Biosci. 2020;15(2):153.

Abstract

There are different types of viruses are found in nature which cause infection in humans and other animals, some causing severe illness and others not. A unique coronavirus termed Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) was isolated from lower respiratory tract sample as the causative agent. The recent outbreak of contagions with SARS-CoV-2 is termed Coronavirus Disease 2019 (COVID-19) by the World Health Organization (WHO). At present, whole world is struggling with COVID-19 disease. COVID-19 quickly spread into at least 215 countries and exterminated more than 300,000 persons by May 15, 2020. This is the time to exercise restrains and caution. Whole world’s many governments, scholars and scientists are engaged for discover the proper treatment until we find proper and right treatment for it we have to be careful to avoid infection. This review article includes characteristics of COVID-19, current scenario of disease, causes and symptoms of disease and how to prevent from its infection.

Keywords

Coronavirus; SARS-CoV-2; COVID-19; Pandemic; Infection

Abbreviations

SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus-2; COVID-19: Coronavirus Disease 2019; WHO: World Health Organization; SARS: Severe Acute Respiratory Syndrome; CoV: Corona-Virus; SARS-CoV: Severe Acute Respiratory Syndrome-Linked Virus; MERS: Middle East Respiratory Syndrome; R0: Basic Reproduction Number; CI: Confidence Interval; HE: Esterase and Hemagglutination; ACE 2: Angiotensin-Converting Enzyme 2; RNA: Ribonucleic Acid; CDC: Europe Center of Disease Control; OSCAR: Oxford Suzhou Centre for Advanced Research

Introduction

The novel SARS-CoV-2 corona virus that emerged in the city of Wuhan, Hubei Province, China, on dated December 8th 2019 and has since caused a large scale COVID-19 pandemic and spread to more than 215 other countries or territories or areas. Corona virus is a type of infected virus which was discovered as novel agent on dated 9th January 2020 [1], with a unique history of confirming the first case of human infection due to avian influenza A H5N1 in 1997 [2] and Severe Acute Respiratory Syndrome (SARS)-associated Corona-Virus (CoV) in 2003 [3].

In spite of the determination to break the transmission of COVID-19, the contagion spread all over China, and in January 2020, cases were reported in Japan, Thailand, and South Korea [4,5]. Within less than 3 months since the detection of the unidentified pathogen, the infection extent to at least 114 countries and caused over 4,000 demises. In India, the first case of the COVID-19 was identified on 30 January 2020, and as of 15 May 2020, a total of 85,940 confirmed cases leading to 2,753 deaths has been reported.

Two unique strains of coronavirus have leaped species from animal to human, spread by human-to-human transmission, and caused severe acute respiratory syndrome leading to high fatality rate in the past 2 decades [6]. Severe Acute Respiratory Syndrome-Linked Virus (SARS-CoV), hitherto unidentified coronavirus traced to horseshoe bats in southern China, caused 8,096 confirmed cases and 774 demises in 29 countries from November 2002 to July 2003 [7]. Now a day’s, the whole world is suffering from COVID-19 disease. This article reviews the characteristics of COVID-19, causes, symptoms, preventions and current scenario of the disease. TABLE 1 briefly describes distinctive features of SARS-CoV-2 in comparison to SARS-CoV [8].

Characteristic SARS (SARS-CoV) MERS (MERS-CoV) COVID-19 (SARS-CoV-2)
First identified location Guangdong, China Jeddah, Saudi Arabia Wuhan, China
Period 2002-2003 2012-ongoing 2019-present
Host of virus
Natural host Bats Bats Bats
Intermediate host Masked palm civet cat or other animal hosts Dromedary camels Pangolins
Terminal host Humans Humans Humans
Mode of transmission Human-to-human through aerosol droplets, opportunistic airborne transmission, nosocomial transmission, fecal-oral transmission, zoonotic transmission Respiratory transmission, zoonotic transmission, nosocomial transmission, limited human-to-human transmission, aerosol transmission Human-to-human through fomites, physical contact, aerosol droplets, nosocomial transmission, zoonotic transmission
Estimated R0 2-5 <1 2-3
Incubation period Mean 4.6 days (95% CI, 3.8-5.8) Median 5.2 days (95% CI, 1.9-14.7) Median 6.4 days (95% CI, 2.2-11.5)
Case fatality rate 9.60% 34.40% 3.80%

Table 1: Differences in epidemiological characteristics of SARS (SARS-CoV), MERS (MERS-CoV), and COVID-19 (SARS-CoV-2).

Morphology and Genome Sequence of COVID-19

Coronaviruses are enveloped, pleomorphic or spherical particles, 150 nm to 160 nm in size, linked with constructive single stranded RNA, unsegmented, nucleoprotein, capsid, matrix, and surface glycoprotein (S-protein) (FIG. 1). Significant viral proteins are nucleocapsid protein (N), membrane (M), spike glycoprotein (S), and envelope small membrane protein (E). TABLE 2 showed structural proteins of COVID-19 and their functions. COVID-19 varies from further coronaviruses by encoding a supplementary glycoprotein that has acetyl Esterase and Hemagglutination (HE) properties [9,10].

Structural protein Function(s) of protein
Nucleocapsid protein (N) Bound to RNA genome to make up nucleocapsid
Spike glycoprotein (S) Critical for binding of host cell receptors to facilitate entry of host cell
Envelope small membrane protein (E) Interacts with M to form viral envelope
Membrane protein (M) Central organizer of CoV assembly
Determines shape of viral envelope
Hemagglutinin-Esterase (HE) Forms a distinct inner fringe of short peplomer

Table 2: Structural proteins of COVID-19 and their functions.

Analytical-Chemistry-extracted-ion-chromatogram

Figure 1. Schematic representation of main structure of COVID-19 showing spikes that form a “crown” like the solar corona, hence the name is coronavirus.

Evaluation of the genome arrangement of the COVID-19, SARS-CoV, and MERS-CoV revealed that COVID-19 has enriched sequence uniqueness with SARS-CoV than the MERS-CoV6. The COVID-19 amino acid arrangement differs from former coronaviruses with polyprotein and S-protein. S-protein has two subunits with single subunit binding directly to the host receptor assisting the entry of virus into cells. The RNA binding domain of the S-protein in COVID-19 has superior homology with SARS-CoV. Studies suggest that the human receptor for COVID-19 might be Angiotensin-Converting Enzyme 2 (ACE 2) [11,12]. Also, other coronaviruses comprising SARS-CoV advantage appearance into human cells through ACE 2. It has been noted that specific CoV do not need to have the full ensemble of structural proteins to make virons, highlighting that certain proteins may be dispensable or compensated by the function of non-structural proteins [13,14].

Characteristics of the Corona Virus (SARS-CoV-2)

The coronaviruses have five vital genes which are for four structural proteins (N, E, M, S) and for viral replication/transcription (Ribonucleic Acid (RNA) dependent RNA polymerase, RdRp). The genome organization is 5’-RdRp-S-E-M-N-3’. This gene order of coronaviruses is highly conserved [15]. Complete genome sequence of SARS-CoV-2 reveals that it is a novel beta coronavirus distinctive from SARS-CoV [16]. The nucleotide sequence of SARS-CoV-2 revealed 79.0% and 51.8% uniqueness with SARS-CoV and MERS-CoV, correspondingly and it is very closely linked to bat-SARS-identical coronavirus (bat-SL-CoVZC45) with 87.6%-89% identity [17,18].

Based on the phylogenetic analysis, the Coronaviridae Study Group of International Committee on Taxonomy of Viruses named the virus SARS-CoV-2, on 11 February, 2020 [19]. On the similar day, the WHO termed the disease initiated by the novel Coronavirus Disease 2019 (COVID-19), in arrangement with WHO best practices for naming of new human infectious disease [20]. Based on the virus genome sequencing data, bats are presumed to be the reservoir of SARS-CoV-2, but the transitional hosts are not identified till date. SARS-CoV-2 enters into the host cell through binding its spike proteins, which regulate host tropism, to host cell receptors [21,22]. Preliminary investigations had proposed that SARS-CoV-2 might share a host cell receptor with SARS-CoV, because the 2 strains have equivalent receptor-binding protein configurations. Consecutive studies revealed that SARS-CoV-2 binds to ACE 2 as SARS-CoV does [23,24]. SARS-CoV-2 was first isolated from a bronchoalveolar lavage sample [16] and RNA of the virus was also detected in nasopharyngeal and throat swabs as well as blood, stool, urine, and saliva [25,26].

Symptoms of COVID-19

Symptoms of this virus are like pneumonia. Potency of SARS-CoV-2 may be mild, moderate or severe based on the strength of the immune system of the infected individual. A certain pattern in the bulk of cases tends to reflect the scientific improvement of the disease. In a proportion that has yet to be known, after around a week, infected person health consequences have unpredictably deteriorated, as respiratory failure has weakened promptly. The life-threatening respiratory failure situations and medical requirements of sepsis and septic shock should be taken seriously [27]. Patients with uncomplicated (mild to moderate) illness generally have signs that comprise slight fever, arid cough, sore throat, fatigue, stomach aches, respiratory irritation and malaise, although testified dyspnea in patients were asymptomatic [28]. Nonrespiratory signs for instance diarrhea are significant to recognize comparative to earlier HCoV infections. Adequate pneumonia respiratory signs for example cough and shortness of breath (or children’s tachypnea, etc.) were reported for patients in some cases [29]. Life-threatening pneumonia fever is initiated by substantial illnesses, respiratory depression or hypoxia (SpO2<90% in the room). Fever is constant with extreme pneumonia [30]. However, fever signs supposed to be properly predictable as slight or occasionally missing, even in thrilling cases of the disease. In kids, cyanosis can occur. The illustration includes a psychiatric disorder, and radiological terminology is used to abolish difficulties with clinical and ventilator supplies that are required for this diagnosis [29]. The extent of hypoxia in several forms of ARDS is different [31]. Moreover, sepsis is a serious organ dysfunction owing to dysregulated host responses to doubted or recognized organ dysfunctions [32]. The clinical depictions of patients with SARS-CoV-2 and sepsis are mainly severe, with an extensive assortment of signs, symptoms (cardiac disorders, for instance extreme dyspnea and hypoxemia, acidosis, altered mental state, abnormal vomiting, and efficient organ variations), and signs of multi-organ shock accessible as hyperbilirubinemia laboratory results [31].

Identify fit symptoms of corona virus infection are following: headache (14%), runny nose (5%), sore throat (14%), fever (88% cases), vomiting (5% cases), shortness of breath (19% cases), joint pain (15%), fatigue (38%), chills (11%), diarrhea (4%), phlegm (33%), dry cough (68%), confirmed by World Health Organization (reports based on 56, 000 lab cases) database.

Clinical Progression and Diagnosis

The mission through Google dataset for SARS-CoV-2 diagnosis (TABLE 3) concluded in five guidelines, webpages with links and recommendations for public knowledge (WHO, Europe Center of Disease Control (CDC), US CDC, US FDA). The incubation phase for COVID-19 is believed to be inside 14 days following exposure, with most cases happening roughly four to five days after acquaintance [33,34]. In an investigation of 1099 patients with affirmed symptomatic COVID-19, the median incubation time period was four days (interquartile run two to seven days) [18]. Utilizing information from 181 openly revealed, affirmed cases in China with recognizable presentation, one displaying study evaluated that side effects would develop in 2.5 percent of contaminated people inside 2.2 days and in 97.5 percent of infected people inside 11.5 days [35]. The median incubation period in this investigation was 5.1 days.

Viral strain Test Samples References
SARS-CoV-2 rRT-PCR; E gene assay; confirmatory testing: RdRp gene assay Respiratory samples from hospitalized -
patients
COVID-19 IgG/IgM rapid test kit Saliva swab samples Commercial kit from
myLAB Box
A colorimetric assay based on gold nanoparticles Saliva swab samples Oxford Suzhou Centre for Advanced Research (OSCAR)
A colorimetric assay based on gold nanoparticles coated with glycans Saliva swab samples Iceni Diagnostics

Table 3: SARS-CoV-2 diagnosis systematic assessment results.

COVID-19 shows with a wide clinical range extending from asymptomatic patients to septic shock, multiorgan brokenness and fatal pneumonia [36]. The rate of asymptomatic infection is hitherto to be defined, since utmost initially asymptomatic infections finally turned symptomatic. COVID-19 is organized reliant on the seriousness of the appearance [36]. The infection might be characterized into mild (no or mild pneumonia; 81%), moderate (mild pneumonia), serious (with dyspnea, hypoxia, or>50 percent lung involvement; 14%), and critical (eg., with respiratory failure, shock, or multiorgan dysfunction; 5%) [37]. The most widely recognized manifestations of patients incorporate fever (98.6%), exhaustion (69.6%), dry cough, and diarrhea [37]. The entire case fatality rate was 2.3%; no deaths were testified among noncritical cases. Symptomatic infection in children appears to be relatively infrequent; when it arises; it is usually mild, although severe cases have been stated [38,39].

Fatality rate of COVID-19 in China is 3.8%; the fatality rate in Wuhan City is 5.8%, in contrast to that of 0.7% in the rest of mainland China. Risk factors of extreme pneumonia or demise incorporate ages 60 or above, and clinical comorbidity, for example, hypertension, cardiovascular sickness, diabetes mellitus, incessant aspiratory infection or threat. Research facility trial of the affirmed COVID-19 cases appeared leukopenia, lymphopenia, mild raised C-receptive protein.

In the meantime, SARS-CoV contamination generally presents with fever. The disease starts with fundamental complaints including myalgia, chills, or fatigue, trailed by dry cough and dyspnea following a couple of days to seven days. Symptoms of upper respiratory tract contamination, for example, rhinorrhea or sore throat are uncommon. Watery looseness of the bowels might be gone within 10%-25% patients in later course of the malady. Serious consideration was required in 20%-30% of patients, with 10% casualty rate. In ages more established than 60 years, casualty rate was half. Death mostly occurred in the third week from the beginning of symptoms.

How the Corona Virus Spreads?

The human Corana Virus (COVID-19) usually spreads from one person to another. It is also transmitted through aerosol [40]. There are several ways which spreads this virus in the environment and person to person. These are ways following: open air coughing and sneezing; close personal contact such as touching or shaking hands; virus is transmitted through air, surface, environmental and personal protective equipment’s [41]; touching a narrow object or surface, then touching nose, mouth or eyes without washing hands; use of infected thing like vegetable and other food items.

Prevention of Corona Virus

Preventive estimates must concentrate on improving disease control conventions, self-isolation, and patient disengagement during the arrangement of clinical consideration. The WHO has prompted against close contact with patients, livestock, and wild animals. Patients and the overall population must cover coughs and sneezes to aid preclude aerosol transmission. Regular hand washing with disinfectant and water is likewise required. As a substitute measure, hand sanitizers can also be utilized. Immunocompromised people are encouraged to maintain a strategic distance from open social occasions. Crisis medication divisions must apply severe cleanliness measures for the control of diseases. Medicinal services faculty must utilize individual defensive equipment for example, face masks like N95 masks, FFP3 masks, gowns, eye assurance, gloves, and outfits [42].

The WHO and similar types of organizations have made the following broad-spectrum guidelines: always clean hands with soap and water or alcohol-containing hand bars; when coughing and sneezing, cover the nose and mouth with a tissue or bent elbow; avoid making close contact with people who have cold or flu-like symptoms; use the mask and after using it dispose by burning of buried; avoid going to public places and crowds; stop hazardous field touch or wildlife interaction; do not bring food items made out of the house; fortify the execution of severe cleanliness measures to stay away from and oversee diseases, especially in the emergency medicine divisions; To keep taking more fluids [43,44]. If having fever, cough and difficulty in breathing, contact the doctor as soon as possible. Be aware of the important information related and follow the advice given by doctor. There is one example of prevention is that Indian government put one day ‘JANTA’ curfew on dated March 22, 2020 for the same.

Current Scenario

According to WHO, it is pandemic disease and found 203 countries, areas or territories and till May 15, 2020 total confirm cases 4,628,821 and confirmed deaths are 308,654 [45]. In India, total 85940 cases are confirmed out of 2753 death and 30258 get recovered till May 15, 2020. The highest confirmed in Maharashtra state which is 29100 and deceased 1068 [46]. Here, we presented the worldwide report of confirmed cases and deaths by country, territory, or conveyance.

Confirmed Cases and Deaths by Country, Territory, or Conveyance

The coronavirus COVID-19 is affecting 213 countries and territories around the world and 2 international conveyances: the Diamond Princess Cruise ship harbored in Yokohama, Japan, and the Holland America's MS Zaandam cruise ship. The day (May 15, 2020) is reset after midnight GMT+0. TABLE 4 showing the report of coronavirus cases overall the world.

S. No. Country Total Cases Total Deaths Total Recovered Active Cases Population
  World 4,628,821 308,654 1,759,701 2,560,466  
1 USA 1,484,285 88,507 327,751 1,068,027 330758784
2 Spain 274,367 27,459 188,967 57,941 46752556
3 Russia 262,843 2,418 58,226 202,199 145926781
4 UK 236,711 33,998 N/A N/A 67841324
5 Italy 223,885 31,610 120,205 72,070 60472650
6 Brazil 220,291 14,962 84,970 120,359 212368566
7 France 179,506 27,529 60,448 91,529 65255646
8 Germany 175,699 8,001 151,700 15,998 83750665
9 Turkey 146,457 4,055 106,133 36,269 84222640
10 Iran 116,635 6,902 91,836 17,897 83853830
11 India 85,940 2,753 30,258 52,929 1378270651
12 Peru 84,495 2,392 27,147 54,956 32912133
13 China 82,941 4,633 78,219 89 1439323776
14 Canada 74,613 5,562 36,895 32,156 37700059
15 Belgium 54,644 8,959 14,301 31,384 11583327
16 Saudi Arabia 49,176 292 21,869 27,015 34742883
17 Mexico 45,032 4,767 30,451 9,814 128759156
18 Netherlands 43,681 5,643 N/A N/A 17130183
19 Chile 39,542 394 16,614 22,534 19095344
20 Pakistan 38,799 834 10,880 27,085 220321573
21 Ecuador 31,467 2,594 3,433 25,440 17608034
22 Switzerland 30,514 1,878 27,100 1,536 8646621
23 Qatar 29,425 14 3,546 25,865 2874647
24 Sweden 29,207 3,646 4,971 20,590 10091340
25 Portugal 28,583 1,190 3,328 24,065 10200306
26 Belarus 27,730 156 8,807 18,767 9449703
27 Singapore 26,891 21 7,248 19,622 5844512
28 Ireland 23,956 1,518 19,470 2,968 4930698
29 UAE 21,831 210 7,328 14,293 9874985
30 Bangladesh 20,065 298 3,882 15,885 164479603
31 Poland 18,016 907 6,918 10,191 37851666
32 Ukraine 17,330 476 4,473 12,381 43765128
33 Israel 16,589 266 12,587 3,736 8637807
34 Indonesia 16,496 1,076 3,803 11,617 273152851
35 Romania 16,437 1,070 9,370 5,997 19252967
36 Japan 16,203 713 10,338 5,152 126523275
37 Austria 16,109 628 14,471 1,010 8999946
38 Colombia 14,216 546 3,460 10,210 50813344
39 South Africa 13,524 247 6,083 7,194 59212004
40 Kuwait 12,860 96 3,640 9,124 4262329
41 Philippines 12,091 806 2,460 8,825 109391934
42 Dominican Republic 11,739 424 3,557 7,758 10833998
43 Egypt 11,228 592 2,799 7,837 102078159
44 S. Korea 11,037 262 9,851 924 51263759
45 Denmark 10,791 537 8,959 1,295 5789665
46 Serbia 10,438 225 4,301 5,912 8741609
47 Panama 9,268 266 6,080 2,922 4305867
48 Czechia 8,406 295 5,381 2,730 10706527
49 Norway 8,219 232 32 7,955 5415870
50 Argentina 7,479 356 2,497 4,626 45142926
51 Australia 7,037 98 6,353 586 25461791
52 Malaysia 6,855 112 5,439 1,304 32312334
53 Morocco 6,652 190 3,400 3,062 36854173
54 Algeria 6,629 536 3,271 2,822 43746275
55 Bahrain 6,583 12 2,640 3,931 1693179
56 Finland 6,228 293 5,000 935 5539658
57 Afghanistan 6,053 153 745 5,155 38810145
58 Kazakhstan 5,850 34 2,707 3,109 18747746
59 Moldova 5,745 202 2,228 3,315 4035100
60 Ghana 5,638 28 1,460 4,150 30986096
61 Nigeria 5,450 171 1,320 3,959 205444156
62 Oman 4,625 20 1,350 3,255 5088900
63 Armenia 4,044 52 1,666 2,326 2962559
64 Luxembourg 3,923 104 3,682 137 624641
65 Bolivia 3,577 164 434 2,979 11652343
66 Hungary 3,473 448 1,371 1,654 9663324
67 Iraq 3,193 117 2,089 987 40100844
68 Cameroon 3,105 140 1,567 1,398 26455880
69 Thailand 3,025 56 2,855 114 69778286
70 Azerbaijan 2,980 36 1,886 1,058 10127539
71 Greece 2,810 160 1,374 1,276 10429161
72 Uzbekistan 2,691 11 2,158 522 33405983
73 Guinea 2,473 15 895 1,563 13083829
74 Honduras 2,460 134 264 2,062 9883952
75 Senegal 2,310 25 890 1,395 16683471
76 Bosnia and Herzegovina 2,236 128 1,336 772 3283253
77 Croatia 2,222 95 1,869 258 4108287
78 Bulgaria 2,174 105 573 1,496 6954648
79 Ivory Coast 2,017 24 942 1,051 26289372
80 Sudan 1,964 91 205 1,668 43710745
81 Cuba 1,840 79 1,425 336 11327461
82 Iceland 1,802 10 1,782 10 340964
83 Estonia 1,766 63 923 780 1326425
84 North Macedonia 1,740 97 1,251 392 2083384
85 Guatemala 1,643 30 135 1,478 17871637
86 Lithuania 1,523 54 965 504 2726669
87 New Zealand 1,498 21 1,428 49 4817264
88 Slovakia 1,480 27 1,131 322 5459317
89 Slovenia 1,465 103 270 1,092 2078903
90 Djibouti 1,309 4 935 370 986127
91 DRC 1,298 50 212 1,036 89181925
92 Somalia 1,284 53 135 1,096 15832072
93 El Salvador 1,210 25 417 768 6482107
94 Mayotte 1,210 16 627 567 271922
95 Gabon 1,209 10 219 980 2218621
96 Tajikistan 1,118 33   1,085 9508770
97 Kyrgyzstan 1,117 14 783 320 6510046
98 Hong Kong 1,053 4 1,019 30 7489265
99 Tunisia 1,035 45 802 188 11802774
100 Maldives 1,031 4 49 978 539287
101 Latvia 970 19 662 289 1888633
102 Sri Lanka 935 9 477 449 21402049
103 Albania 916 31 705 180 2878180
104 Guinea-Bissau 913 3 26 884 1961700
105 Cyprus 910 17 481 412 1206248
106 Lebanon 891 26 246 619 6829118
107 Niger 885 51 684 150 24081508
108 Costa Rica 843 9 542 292 5088192
109 Mali 806 46 455 305 20170087
110 Kenya 781 45 284 452 53611938
111 Burkina Faso 780 51 595 134 20824384
112 Andorra 761 49 604 108 77250
113 Paraguay 759 11 193 555 7121225
114 Uruguay 732 19 553 160 3472233
115 Diamond Princess 712 13 651 48  
116 Georgia 671 12 393 266 3990097
117 Zambia 654 7 124 523 18312920
118 San Marino 652 41 189 422 33922
119 Jordan 596 9 401 186 10190185
120 Equatorial Guinea 594 7 22 565 1396494
121 Channel Islands 549 43 457 49 173659
122 Malta 532 6 458 68 441397
123 Jamaica 511 9 121 381 2959554
124 Tanzania 509 21 183 305 59498998
125 Venezuela 459 10 229 220 28445691
126 Sierra Leone 447 27 97 323 7955312
127 Réunion 441   354 87 894505
128 Taiwan 440 7 387 46 23811452
129 Chad 428 48 88 292 16360644
130 Congo 391 15 87 289 5499613
131 Palestine 375 2 315 58 5085377
132 Benin 339 2 83 254 12079722
133 Isle of Man 334 24 285 25 84977
134 Mauritius** 332 10 322 0 1271508
135 Cabo Verde 326 2 67 257 555212
136 Montenegro 324 9 311 4 628056
137 Vietnam 314   260 54 97227060
138 Haiti 310 20 29 261 11384587
139 CAR 301   13 288 4818688
140 Ethiopia 287 5 112 170 114576005
141 Rwanda 287   177 110 12908515
142 Nepal 273   36 237 29067490
143 Togo 263 11 96 156 8252463
144 Madagascar 238   112 126 27593744
145 South Sudan 236 4 4 228 11176820
146 Sao Tome and Principe 235 7 4 224 218619
147 Liberia 219 20 108 91 5041588
148 Uganda 203   63 140 45538682
149 Martinique 192 14 91 87 375301
150 Eswatini 190 2 66 122 1158626
151 French Guiana 189 1 124 64 297623
152 Faeroe Islands* 187   187 0 48840
153 Myanmar 182 6 89 87 54363807
154 Guadeloupe 155 13 109 33 400116
155 Gibraltar 147   144 3 33692
156 Brunei 141 1 135 5 436944
157 Mongolia 135   20 115 3271362
158 Bermuda 122 9 66 47 62306
159 Cambodia* 122   122 0 16688891
160 Mozambique 119   42 77 31134613
161 Guyana 116 10 43 63 786077
162 Trinidad and Tobago 116 8 107 1 1398925
163 Yemen 106 15 1 90 29737584
164 Aruba 101 3 93 5 106709
165 Bahamas 96 11 41 44 392764
166 Monaco 96 4 87 5 39207
167 Cayman Islands 94 1 55 38 65623
168 Barbados 85 7 65 13 287332
169 Liechtenstein 82 1 55 26 38114
170 Sint Maarten 76 15 46 15 42813
171 Libya 64 3 28 33 6859160
172 Malawi 63 3 24 36 19062368
173 French Polynesia 60   59 1 280704
174 Syria 50 3 36 11 17442911
175 Angola 48 2 17 29 32723364
176 Macao 45   43 2 648186
177 Zimbabwe 42 4 13 25 14834717
178 Saint Martin 39 3 30 6 38579
179 Eritrea* 39   39 0 3540041
180 Mauritania 29 3 7 19 4632917
181 Nicaragua 25 8 7 10 6614394
182 Antigua and Barbuda 25 3 19 3 97826
183 Botswana 24 1 17 6 2345288
184 Timor-Leste* 24   24 0 1315109
185 Gambia 23 1 10 12 2407297
186 Grenada 22   14 8 112458
187 Bhutan 21   5 16 770517
188 Laos 19   14 5 7261799
189 Belize** 18 2 16 0 396673
190 Fiji 18   15 3 895624
191 New Caledonia* 18   18 0 285148
192 Saint Lucia* 18   18 0 183522
193 St. Vincent Grenadines 17   14 3 110896
194 Curaçao 16 1 14 1 164009
195 Dominica 16   15 1 71964
196 Namibia 16   13 3 2534815
197 Burundi 15 1 7 7 11841556
198 Saint Kitts and Nevis 15   14 1 53151
199 Falkland Islands* 13   13 0 3466
200 Turks and Caicos 12 1 10 1 38649
201 Vatican City 12   2 10 801
202 Comoros 11 1 3 7 867116
203 Montserrat** 11 1 10 0 4992
204 Greenland* 11   11 0 56758
205 Seychelles 11   10 1 98270
206 Suriname** 10 1 9 0 585963
207 MS Zaandam 9 2   7  
208 British Virgin Islands 8 1 6 1 30206
209 Papua New Guinea* 8   8 0 8924516
210 Caribbean Netherlands* 6   6 0 26192
211 St. Barth* 6   6 0 9873
212 Western Sahara* 6   6 0 595342
213 Anguilla* 3   3 0 14986
214 Lesotho 1     1 2140096
215 Saint Pierre Miquelon* 1   1 0 5797
  Total 4,628,821 308,654 1,759,701 2,560,466  

Table 4: All countries report of coronavirus cases (Data obtained from May 15, 2020).

Conclusion

The COVID-19 pandemic is scattering transversely the world at an alarming frequency. It has caused more contagions and demises as compared with SARS or MERS. Based on R0 values, it is considered that SARS-CoV-2 is more infectious than SARS or MERS. Aging and immunocompromised patients are at the extreme threat of mortality. The prompt extent of disease permits intense investigation and quarantine protocols to preclude further transmission. Till date, no chronic medication or vaccine has been developed. Modern treatment approaches are intended at symptomatic care and oxygen therapy. In future, prophylactic vaccination will be compulsory for the imminent prevention of COV-associated epidemic or pandemic.

Acknowledgements

Authors would like to thank Department of Botany, Mohanlal Sukhadia University, Udaipur, Rajasthan, for providing necessary facilities. Authors are also thankful to online available sources, organizations like World Health Organization; Ministry of Home Affairs, Government of India, etc.

Conflict of Interest Statement

No potential conflict of interest relevant to this article was reported.

Funding Sources

There is no funding source available.

References