CORONAVIRUS, COVID 19 PANDEMIC AND DENTAL CARE ( 3 )

The novel coronavirus is the cause of the Coronavirus disease 2019 (COVID- 19) pandemic and made severe harm across the globe with more than 37 million people are infected worldwide, affected around 230 countries, and exceeding one million deaths till today. The outbreak of COVID-19 by a new strain  Coronavirus called Novel Coronavirus, also named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) identified in December 2019 and not caused any disease in human beings before. Common symptoms are fever, cough, loss of taste, loss of smell and, shortness of breath. On 30 th January 2020 World Health Organization (WHO) announced the current COVID-19 outbreak a Public Health Emergency of International Concern and on March 11 th declared it as a pandemic. The virus spreads when in close contact, most often via small droplets produced by coughing, sneezing, and talking. As the infection is airborne, Dentists are at high risk since they are working in close proximity with the patients. Dental procedures generate micro aerosols, causes the spreading of the virus. Therefore, Dentists should take proper infection control measures, protocol-oriented practice during procedures, reduce the use of aerosol-generating instruments, and carry out only emergency treatments. The working environment must be safe for the dentist, staff, and patients. Also, patients should seek treatment only for urgent situations like pain, swelling, uncontrolled bleeding, and dental trauma.

COVID 19 PANDEMIC>

CONTENTS >

INTRODUCTION

COVID 19 OUTBREAK

EPIDEMIC, ENDEMIC $ PANDEMIC

STRAINS OF COVID 19 VIRUS

MODE OF SPREAD

SIX CLUSTERS OF SYMPTOMS OF COVID 19

DIAGNOSIS, PREVENTION, MANAGEMENT

SUMMARY

Introduction

The incidence of severe respiratory infection of chicken in the mid-1930s was thought to be the earliest known disease by coronaviruses, and the human coronaviruses identified in the year 1965. The name “coronavirus,” coined in the year 1968, because of the presence of a “corona”-like or crown-like structure on its surface. Coronaviruses are the largest known RNA Viruses (CoVs) belong to the family Coronaviridae, subfamily coronavirinae in the order nidovirales. Coronaviruses were considered as minor pathogens of humans and caused 15%- 25% of all “common colds, until the outbreak of Severe

acute respiratory syndrome (SARS) in 2002. The outbreak of Coronavirus disease (COVID-19), by a newstrain of Coronavirus called Novel Coronavirus, also named Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) identified in December 2019 at Wuhan, China is the cause of the ongoing

pandemic.

COVID 19 Outbreak

Human coronaviruses cause upper and lower respiratory tract infections. Until the outbreak of SARS,the coronaviruses were considered as minor pathogens and caused only upper respiratory infections. The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infect the lower respiratory tract. A new coronavirus was identified in December 2019 as the cause of a disease outbreak called Novel Corona Virus Disease known to be originated in Huanan Seafood Wholesale Market, Wuhan, China. Many people with

pneumonia of unknown etiology were admitted to Wuhan hospital and on 29 th December 2019, the cases were reported to the Center for Disease Control (CDC). Researchers found that patients had worked in the Huanan Wholesale Market, a selling hub of animals. By laboratory analysis etiology was

confirmed and the causative organism, a novel β genus Coronavirus, responsible for the ongoing pandemic, and the disease was named Novel Coronavirus- infected Pneumonia (NCIP).

Epidemic, Endemic $ Pandemic

In medical science and epidemiology, the level of disease occurrence is described as an epidemic, endemic, or pandemic. An Epidemic is the outbreak of a disease in a community and it spreads quickly to a larger area. Examples of major epidemics are cholera, dengue, and malaria. An Endemic refers to the

constant occurrence of an infectious agent or disease within a geographic area. Malaria, a mosquito-borne infection is endemic in Africa. A Pandemic is an epidemic that spreads across countries or different continents. Influenza, smallpox, and bubonic plague are some of the pandemic and cruel killers in the

history of human beings. Up to 10% of the world's population died in the bubonic plague and the smallpox pandemic has killed around 300-500 million people worldwide. WHO declared COVID-19 to be a pandemic on 11 th March 2020 because the illness has spared all over the world.

Strains Of COVID 19 Virus

Researchers of China at the beginning of the COVID-19 pandemic identified two Novel coronaviral strains named “S” and “L.” The S-strain was thought to be jumped to humans from animals, mutated to L strain and the L strain was responsible for around 70% of cases of the ongoing pandemic.

Presently, six strains of coronaviruses are identified. By January 2020, emerged strains V and G. To date, the most widespread strain is G: which mutated into strains GR and GH. L and V strains are disappearing slowly and S strain is restricted in some areas of the US and Spain. Thus, the six viral strains of COVID- 19 are ‘S, L, V, G, GR, and GH’. Among these, G, GH, and GR are continuously increasing worldwide and constituting around 74% of all strains.

 By mid-August 2020, Malaysian health authorities found out a new strain of the COVID-19 virus, formed because of D614G spike protein mutation, which is 10 times more infectious than the previous strains. The number of "spikes" on the coronavirus is increased because of mutation, which leads to increased infectivity.

Mode Of Spread

COVID-19 virus invades and affects the cell through angiotensin-converting enzyme 2 (ACE2) cell receptor and are numerous throughout the respiratory system and also in the salivary gland duct epithelium. The virus spreads among people during close contact, mainly through small droplets produced by coughing, sneezing, and talking. Males are affected more. It can also be transmitted by touching the eyes, nose, and mouth after touching contaminated surfaces with the hands and by people who are not showing symptoms, the so-called asymptomatic carriers. Super spreading is the transmission of

infection to a large number of individuals from a single source or a person. A cluster refers to an aggregation of cases in a particular area and time that are suspected to be greater than the number expected. Community spread is the spread of a communicable disease to people in a particular geographic area who have no known contact with other diseased individuals. The virus can survive at room temperature for five to nine days and it cannot stay long in a warm humid climate. A group of Australian researchers proved that the Coronavirus can survive on inanimate surfaces like glass, steel, cell phone, and the tab at a temperature of around 20 °C and relative humidity of around 40-50%.

Six Clusters of Symptoms of COVID 19

COVID-19 seems to affect some people harder than others. Even though age and general health status are the crucial factors, a large number of young healthy people are also severely getting affected. Apart from common symptoms, skin rashes, and oral rashes are also been reported.

There are six main clusters of symptoms that are identified so far based on the progression and severity of the condition. They are, 1."Flu-like" with no fever - Headache, loss of smell( anosmia), sore throat, cough, muscle pain, and no fever, 2. ;"Flu-like"; with fever - Headache, sore throat, anosmia, cough, loss of appetite, and fever, 3. Gastrointestinal - Headache, diarrhea, anosmia, sore throat, chest pain, 4. Severe level one, fatigue- Headache, hoarseness, cough, anosmia, fever, chest pain, and fatigue. 5.Severe level two, confusion - Headache, loss of appetite, anosmia, cough, fever, sore throat, hoarseness, chest pain, fatigue, and confusion and 6. Severe level three, abdominal and respiratory - Headache, loss of appetite, anosmia, cough, hoarseness, fever, sore throat, chest pain, abdominal pain, fatigue, confusion, muscle pain, shortness of breath and diarrhea.

“Emergency signs are trouble breathing, persistent chest pain, confusion, inability to stay awake and bluish lips or face”. Many COVID- 19 patients present with pronounced arterial hypoxemia without

showing signs and symptoms of respiratory distress. This phenomenon is called ‘happy hypoxia or silent hypoxemia.’

Prevention, Diagnosis, Management

As there is no effective treatment or vaccination as of date, the only modality to control infection is prevention. For that, clean the hands often with soap and water or with a minimum of 60% alcohol- containing hand rub at least for 20 seconds, maintain a safe distance of about 6 feet or 2 meters, roughly around two arm’s length to one another, keep a distance from the people who are in the high-risk group and are in quarantine, wear a face mask in public places, avoid touching mouth, nose, or eyes frequently with hands, and cover nose and mouth with the bent elbow or tissue while coughing or sneezing.

Diagnosis is chiefly based on symptoms and COVID tests. COVID tests are mainly diagnostic tests and antibody tests. A diagnostic test shows the active coronavirus infection. A diagnostic test is classified again into an antigen test and molecular test. The antigen test detects specific protein on the

surface of the virus and the test is less sensitive but more specific. So, more chance of false-negative results, and the false-positive result is unlikely. Molecular tests, such as Real-Time Polymerase Chain Reaction (RT-PCR), Nucleic Acid Amplification Test (NAAT), and Loop-Mediated Isothermal

Amplification (LAMP) tests, detect the virus’s genetic material. These tests are more sensitive, more accurate, and reliable. An antibody test is a serological or blood test designed to detect whether the person has developed antibodies to COVID- 19. Antibodies are made by the immune system in response

to a threat such as viruses. The antibody which appears first during infection is IgM and it begins to rise after 1 week of the initial infection, while the IgG appears later usually after14 days, and may last for 6 months or more. The presence of Ig M indicates active infection and IgG alone in the blood shows the patient is recovered. An Enzyme-Linked Immunosorbent Assay (ELISA) is a biochemical technique that can detect antigens or antibodies.

Along with the preventive measures like use of alcohol hand rubs, mask, and social distancing, need to practice healthy lifestyles like maintaining of regular sleep for six to eight hours, stay hydrated by drinking at least 2 to 3 liters of water per day, manage anxiety and stress, do regular exercise, eat balanced

diet including carbohydrate, minerals, and vitamins mainly A, D, and C. Also stop habits like smoking and alcohol consumption, as smoking aggravates respiratory distress and alcoholism alter stomach epithelium, absorption of nutrients, and causes dehydration. Classify the patient to asymptomatic, mild,

moderate, severe, or critical based on the clinical presentation.

Asymptomatic cases are at home in quarantine for a minimum of 14 days, symptomatic treatment for mild and moderate cases, treat the fever with paracetamol 500mg or 650mg, ORS for diarrhea, and steam inhalation for runny nose. If the patient develops difficulty in breathing, persistent chest pain, confusion, or bluish discoloration of face and lips seek emergency medical intervention. Strategies tried so far for the treatment of COVID- 19 are, drugs such as Hydroxychloroquine and Azithromycin, Convalescent plasma, Steroids like Dexamethasone, and Hydrocortisone, antiviral Remdesivir, and adjuvant therapy with Vitamin D and C. Vaccine is still in different stages of development. Researchers are trying to develop a vaccine by making use of an inactive virus, non-replicating viral vector, recombinant protein, and so on.

Silent hypoxia can be monitored by Pulse oximetry technology and oximeters are small non-invasive devices that show immediate readings of blood oxygen levels by clipping the device on the index finger of patients. If the reading is less than 95, the oxygen saturation in the blood is low and needs emergencymedical consultation.

Summary

1.December 2019, a disease outbreak called Novel Corona Virus Disease known to be originated

in Huanan Seafood Wholesale Market, Wuhan, China, responsible for the ongoing COVID 19

Pandemic.

2. There are six main clusters of symptoms that are identified so far based on the progression and severity

of the condition.

3. Along with preventive measures like the use of alcohol hand rubs, masks, and social distancing, need to

practice healthy lifestyles.

4. Seek emergency medical intervention if showing emergency signs.