What is COVID-19?
• This is an infectious disease that was discovered to causes a cluster of pneumonia cases first identified in Wuhan, China.
• It is caused by the 2019 Novel Coronavirus, formerly known as “2019 novel coronavirus (2019-nCoV)” and the disease was officially named COVID-19, by the World Health Organisation on February 11, 2020.
• The COVID-19 is an abbreviation of, CO- corona, VI-Virus and D-Disease and 19 represents the year it was first identified (2019).
• It is a new disease that has been noted to cause mild upper respiratory tract illnesses in humans.
• It was declared a pandemic by the WHO, on March 11, 2020.
What causes COVID-19?
• COVID-19 is caused by a Coronavirus that is named the Novel Coronavirus, which was first identified in Wuhan China in December 2019.
• The Novel Coronavirus was named the Severe acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2).
What is SARS-CoV-2?
• This is the novel Coronavirus of 2019 that causes the infectious disease, knows as COVID-19.
• SARS-CoV-2 is the abbreviation of Severe Acute Respiratory Syndrome Coronavirus-2. ‘2’ represents a type two of the first Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), identified in humans in Guangdong province of southern China in 2002.
What are the symptoms of COVID-19?
• COVID-19 elicits symptoms similar to those of common cold and flu.
• The symptoms include fever, tiredness, and cough with some patients having general body aches and pain, nasal congestion, running nose, sore throat and/or diarrhea.
• The symptoms are normally mild and their onset is gradual.
• Some individuals who are infected may not show symptoms.
• Most people, about 80%, have been noted to recover from the disease without special treatment while the others who are immunocompromised (elderly and those with underlying conditions such as diabetes, blood pressure) or immune-suppressed (heart problems), develop serious illness associated with difficulty in breathing.
• Seek medical attention if experiencing any of the mentioned symptoms.
How long does the COVID-19 infection last?
• There is no global standard of the longevity of COVID-19 infection affected countries have adopted different guidelines as to when a Covid-19 patient is cleared for discharge.
• A patient is stated to have recovered after testing negative for at least two swabs within 24 hours apart and he can be discharged.
• This ensures the recoveree does not infect others when discharged to the community.
What are the risk factors for COVID-19?
• Those most at risk of contracting the disease are individuals who have come into contact with infected patients or persons in the pre-symptomatic phase of the disease infection.
• Contracting the disease can be through physical touching the infected droplets of the infected person.
• The disease is much more severe if the individual exposed to the virus is an elderly person, he/she has an underlying condition such as diabetes, heart problems, hypertension.
• Health workers who are handling COVID-19 patients are also at risk because they come to very close contact with the patients.
• Caregivers for COVID-19 patients are also at risk.
• Persons who have traveled from COVID-19 affected countries in recent times, since the outbreak of the Viral infection.
What is the incubation period of the virus that causes COVID-19?
• The incubation period is the time between catching the virus and onset of symptoms of the disease.
• The estimated incubation period of COVID-19 ranges from 1-14 days, most commonly around 5 days, according to the WHO.
Transmission and Diagnosis of COVID-19
What are the sources of the virus?
• Coronaviruses are known to be zoonotic viruses, originating from animals especially wild animals such as bats, camels, cats, which get transmitted to humans.
• Coronaviruses naturally live in these animals circulating within their systems and when transmitted to humans through eating undercooked meat of these animals or coming into contact with the infected animal droplets and feces.
• Ones the virus infects the humans causing respiratory illnesses, and humans also become a source of viral transmission to other humans, by also coming into contact with the respiratory droplets from infected persons.
How is COVID-19 transmitted?
• The virus can be transmitted from person to person through small infected droplets from the nose or/and mouth, spread when a person with COVID-19 coughs or exhales.
• These droplets can land on objects and surfaces around the person.
• Other people then contract the infection by touching these objects and/or surfaces, then touch their eyes and/or nose and/or mouth.
• People can also contract the infection when they breathe in droplets from a person with COVID-19 who cough or exhale droplets.
• This explains the importance of social distancing of at least 1 meter away from a person who is sick.
Can the virus that causes COVID-19 be transmitted through the air?
• Studies have suggested that the virus that causes COVID-19 is mainly transmitted through contact with the respiratory droplets of an infected person rather than through air.
Can CoVID-19 be caught from a person who has no symptoms?
• Yes. The disease is mainly spread through infected respiratory droplets from an infected person who coughs.
• However, the risk of contracting the disease from an asymptomatic person is very low and since people with COVID-19 experience mild symptoms, there is a possibility of catching COVID-19 from a person who has a mild cough and is not feeling ill.
• The WHO is still assessing research into the period of transmission of COVID-19 with continued updates.
Can I catch COVID-19 from the feces of someone with the disease?
• Yes, however, the risks seem to be low.
• Earlier investigations indicated that the virus can be shed in feces in some cases, but the spread through this route is not a main feature of the outbreak according to the WHO.
• Ongoing research is being assessed by the WHO on the way COVID-19 is spread and they will continue to share new findings and since this is a risk, it is also another reason to maintain high hygienic standards in washrooms, hand washing after using the washrooms and also before eating.
How long does the virus remain alive on surfaces?
• According to the WHO, it is not certain how long the virus causing COVID-19 lasts on the surface but it has tendencies similar to other coronaviruses, to mean, research has shown that the virus causing COVID-19 can survive for a few hours to several days (3 days) depending on the type of surface, temperature or humidity of the environment.
• It is advisable to disinfect surfaces that are suspected to harbor the virus to kill the virus and offer protection to individuals.
• Clean your hands with alcohol-based hand washes or wash with water and soap. Avoid touching your eyes, mouth and/or noses.
What is a community spread?
• Community spread means people have been infected with the virus in an area, including some who are not sure how or where they became infected.
Can I contract COVID-19 by receiving a package from an affected country such as China?
• No. It is unlikely to catch the virus that causes COVID-19 from a package that has moved, traveled and been exposed to different atmospheric conditions and temperatures.
Can pets be infected with COVID-19?
• Yes and No.
• So far we have only had a single case of a dog getting infected with the COVID-19 from its owner who also tested positive to the disease, in Hong Kong.
• This was first reported and published by the World Organisation for Animal Health (OIE).
• However, besides that, there is no evidence that a dog or cat or any pet can transmit COVID-19. The WHO is continuously monitoring the latest research on this and topics emerging from researches on COVID-19
Are pregnant women at the risk of getting COVID-19?
• Currently, there is no documented report on the susceptibility of pregnant women to COVID-19.
• According to the CDC, pregnant women experience immunological and physiological changes which may make them more susceptible to viral respiratory infections including COVID-19.
• They also might be at risk for severe illness, morbidity or mortality compared to the general population as observed in cases of other related coronavirus infections [including severe acute respiratory syndrome coronavirus (SARS-CoV)* and Middle East respiratory syndrome coronavirus (MERS-CoV)] and other viral respiratory infections, such as influenza, during pregnancy.
• Pregnant women should engage in the usual preventive action to avoid infection like washing hands often and avoiding people who are sick.
Can COVID-19 be passed from pregnant woman to the fetus or newborns and during breastfeeding?
• According to the CDC, there is no report on if a pregnant woman with COVID-19 can pass the virus to her fetus or baby during pregnancy or delivery.
• No infants born to mothers with COVID-19 have tested positive for the COVID-19 virus.
• In these cases, which are a small number, the virus was not found in samples of amniotic fluid or breastmilk.
Diagnosis, Treatment, and Prevention of COVID-19
How is COVID-19 diagnosed?
• The FDA among other laboratories are in coordination to produce standard rapid tests for the COVID-19. Currently, the diagnosis of COVID-19 is:
• The Panther Fusion® SARS-CoV-2 Assay is a real-time RT-PCR- It is an in-vitro diagnostic test for qualitatively detecting RNA from SARS-CoV-2 isolated from the nasopharyngeal (NP) and oropharyngeal (OP) swab specimens obtained from individuals who meet COVID-19 clinical and/or epidemiological criteria.
• Serological testing to confirm immunological responses to the specific virus, SARS-CoV-2 for example, cytokine identification, measurement, and quantification.
• in vitro isolation and cultivation of the virus in Vero cell lines.
Can I test negative for COVID-19 then later test positive?
• Using the CDC-developed diagnostic test, a negative result means that the virus that causes COVID-19 was not found in the person’s sample. In the early stages of infection, it is possible the virus will not be detected.
• For COVID-19, a negative test result for a sample collected while a person has symptoms likely means that the COVID-19 virus is not causing their current illness.
How can I protect myself from COVID-19 and prevent the spread of the infection?
• For protection and prevention of spread, the WHO has stipulated measures which we should practice to reduce and prevent the spread of the disease.
• These measures are intended for everyone to practice and there are continued updates on the website and through public health authorities for every affected country for new developments, to be followed.
• Some countries have seen a decline in the infection spread by taking and practicing these measures, such as China and Indonesia.
• However, the situation is unpredictable therefore regular updates can be monitored from the latest news.
Protection measures for everyone
It involves taking simple precautions:
• Regularly and thoroughly clean your hands with an alcohol-based hand rub or wash them with soap and water.
Why? Washing your hands with soap and water or using alcohol-based hand rub kills viruses that may be on your hands.
• Maintain at least 1 meter (3 feet) distance between yourself and anyone who is coughing or sneezing.
Why? When someone coughs or sneezes they spray small liquid droplets from their nose or mouth which may contain the virus. If you are too close, you can breathe in the droplets, including the COVID-19 virus if the person coughing has the disease.
• Avoid touching eyes, nose and mouth.
Why? Hands touch many surfaces and can pick up viruses. Once contaminated, hands can transfer the virus to your eyes, nose or mouth. From there, the virus can enter your body and can make you sick.
• Make sure you, and the people around you, follow good respiratory hygiene. This means covering your mouth and nose with your bent elbow or tissue when you cough or sneeze. Then dispose of the used tissue immediately.
Why? Droplets spread the virus. By following good respiratory hygiene you protect the people around you from viruses such as cold, flu and COVID-19.
• Stay home if you feel unwell. If you have a fever, cough and difficulty breathing, seek medical attention and call in advance. Follow the directions of your local health authority.
Why? National and local authorities will have the most up to date information on the situation in your area. Calling in advance will allow your health care provider to quickly direct you to the right health facility. This will also protect you and help prevent the spread of viruses and other infections.
• Keep up to date on the latest COVID-19 hotspots (cities or local areas where COVID-19 is spreading widely). If possible, avoid traveling to places – especially if you are an older person or have diabetes, heart or lung disease.
Why? You have a higher chance of catching COVID-19 in one of these areas.
For persons who are in or have visited affected areas in recent times (past 14 days) need to follow the above measures (protection measure for everyone) in addition to:
• Self-isolation (self-quarantine) by staying at home if you develop mild symptoms and you feel unwell with fever, headache and low-grade fever (37.3°C) an a running nose, until you recover or visit a medical facility promptly for a checkup, to identify the cause of the symptoms. Wear a mask to avoid infecting people around you. Why? To avoid contact with others and to also help the facility protect you and others from COVID-19 and spreading it as well as infections from other viruses.
• Share your travel history with the medical or health care provider or any contact with a recent traveler, in case you have developed symptoms such as headaches, low-grade fever, coughing, and runny nose. Why? This will help the medical or health care provider take necessary precautions and also help guide you to the right health facility to prevent the spread of COVID-19 and other viruses. this will also help the authorities to track trace other persons who might have been exposed to COVID-19, by interacting with you.
Do face masks protect against COVID-19?
• Yes and No.
• Wearing of masks is advisable for persons who have symptoms of COVID-19 or are coughing and also for health caregivers, workers and if you are taking care of a patient with COVID-19. Disposable masks can only be used ones. But if you are not ill or not taking care of an ill person, you are simply wasting a mask that can be helpful in preventing the spread of the COVID-19 and other viruses, since there is a worldwide shortage of masks. The WHO advises people to use masks wisely. WHO advises the rational use of medical masks to avoid unnecessary wastage of precious resources and misuse of masks.
• However, for those wearing masks to protect themselves from contracting COVID-19, you need to know that masks are not completely protective measures against COVID-19. This is because COVID-19 is spread by coming into contact with the respiratory droplets on an infected person. The droplets can enter the eyes or nose and mouth of an uninfected person so despite protecting your nose and mouth, the droplets can still enter through the eyes, which means one is not completely safe by wearing a face mask. Although, masks will make some difference if you’re walking around town or taking a bus.
• So masks are crucial for the health and social care workers looking after patients and are also recommended for family members who need to care for someone who is ill – ideally, both the patient and carer should have a mask.
• The most effective ways to protect yourself and others against COVID-19 are to frequently clean your hands, cover your cough with the bend of elbow or tissue and maintain a distance of at least 1 meter (3 feet) from people who are coughing or sneezing
What type of masks are used in protection against COVID-19?
• There are two well-known masks that can be used during the COVID-19 pandemic to protect against its transmission and spread. They are the surgical masks and N95 respirator masks
What protective gear is used by health workers to protect them from contracting COVID-19?
• According to the CDC, the personal protective gear for health workers are gowns, coveralls, gloves, and respirators.
• The gowns are meant to protect against microorganisms and the type of gown is based on the level of risk of contamination. Areas of surgical and isolation are critical zones and therefore surgical gowns and isolation gowns are uses respectively because of direct contact with blood, body fluids and/or other potentially infectious materials. Gowns are easy to put on and take off. they are the most common and most familiar within a health care set up for health workers, and training must be done for correct use. The surgical and isolation gowns do not provide continuous whole-body protection, they have openings on the back and the lower parts of the legs.
• Coveralls provide 360° protection since they are designed to cover the whole body including the back and lower legs, head, and feet as well. However, they generate a lot of heat on the wearer and they are a lot heavier because of the extra fabric added to it.
• Gloves – Nonsterile disposable patient examination gloves, are used for routine patient care in healthcare settings, and they are appropriate for the care of patients with suspected or confirmed COVID-19.
• Respirators – are the personal protective devices that are worn on the face or head and cover at least the nose and mouth. A respirator is used to reduce the wearer’s risk of inhaling hazardous airborne particles (including infectious agents), gases or vapors. Respirators, including those intended for use in healthcare settings, are certified by the CDC/NIOSH. In the wake of the COVID-19, N95 mask respirators are recommended by the CDC and the WHO for use by healthcare workers.
How is social distancing helping in preventing COVID-19 transmission?
• Social distancing is maintaining at least 1 meter (3 feet) between yourself and anyone who is coughing or sneezing, as defined by the WHO.
• Social distancing has reduced and slowed down the spread and transmission of COVID-19, with a notable decrease in the number of new cases in affected countries that have practiced the social distancing measures including China, EU countries, UK and Indonesia.
Is there a COVID-19 Vaccine or drug for the treatment of COVID-19?
• No. To date, there is no vaccine yet nor is there a specific antiviral drug to treat and/or prevent COVID-19.
• However, infected patients’ symptoms by symptomatic management and supportive care, to relieve the pain caused by the symptoms. seriously infected individuals should be hospitalized To date, there is no vaccine and no specific antiviral medicine to prevent or treat COVID-2019.
• Research investigations are ongoing to come up with possible vaccines and drug treatments.
• Some drugs are being tested through clinical trials in coordination with the World Health Organisation with major efforts to prevent and treat COVID-19.
• It is advised that the most effective way to protect yourself and others from the viral infection is to frequently clean hands, cough while covering yourself with a tissue or with the bend of the elbow, and maintain a social distance of about 1 meter (3 feet) from people who are coughing and sneezing.
• The most effective ways to protect yourself and others against COVID-19 are to frequently clean your hands, cover your cough with the bend of elbow or tissue, and maintain a distance of at least 1 meter (3 feet) from people who are coughing or sneezing.
Are antibiotics effective in preventing or treating the COVID-19?
• No. Antibiotics are naturally designed to work against bacterial infections and therefore they do not work against viruses or viral infections. Since COVID-19 is a viral infection, antibiotics can not be used to prevent or treat it. And NOTE, antibiotics should only be taken by a physician’s prescription to treat a bacterial infection.
How can we stop the stigmatization of COVID-19 recovered patients?
• The outbreak of COVID-19 has been a stressful time for people and their communities gripped with fear and anxiety. This may lead to social stigma among the people, places, and things that have been affected. Stigmatization and discrimination can occur when people associated with the disease, COVID-19 within a population or a nation or after a recoveree has been discharged or one who has been released from COVID-19 quarantine, besides not being a risk of spread.
• Stigma affects the emotional and mental health of those affected. Stopping stigma is important in making communities and community members resilient. And we all can stop the stigmatization by knowing the facts and sharing them with the community.
• As documented by the CDC, to stop the stigmatization of these groups, communicators and the public health officials can help counter stigma during the COVID-19 response by:
• Maintain the privacy and confidentiality of the patients they tend to.
• Raising awareness to the people about COVID-19 without causing fear, by educating them with accurate information about how the virus spreads.
• Shun negative behavior such as negative statements on social media about groups of people or the exclusion of people who pose no risk from regular activities.
• Quickly communicate the risk or lack of risk from associations with products, people, and places.
• Be cautious about the images you share ensuring they do not enforce stereotypes.
• Freely engage and interact with the stigmatized groups through the media and social platforms.
• Thank healthcare workers and responders. People who have traveled to areas where the COVID-19 outbreak is happening to help have performed a valuable service to everyone by helping make sure this disease does not spread further.
• Show social support for people, friend and relatives who are in the affected areas and those who have returned from China.
How is SARS-CoV-2 different from SARS-CoV-1, MERS-CoV, and Influenza?
• SARS-CoV-2, Severe Acute Respiratory Syndrome CoronaVirus, type 2 is the novel coronavirus that causes COVID-19, currently, causing the ongoing pandemic. SARS-CoV, Severe Acute Respiratory Syndrome type 1 is another type of Coronavirus that caused the Severe Acute Respiratory Syndrome (SARS) in 2003 and MERS-CoV, Middle East Respiratory Syndrome, also another type of Coronavirus that was responsible for causing the Middle East Respiratory Syndrome, also a respiratory tract illness, in the Middle East originating from Saudia Arabis in 2012. Lastly, the influenza virus is the virus known to cause flu, H1N1 (in 2009).
• These viruses have a genetic relationship but they cause different diseases with different levels of severities, to mean SARS was more deadly but less infectious, while COVID-19 is less deadly but much more contagious and MERS.
Diagnosis of Novel Coronavirus, SARS-CoV-2 (COVID-19)
• Lab diagnosis refers to the identification, examination & confirmation of pathogens in the lab.
• The diagnosis of virus infection can be established in several ways, often used together, namely:
1. Detection of virus particles, viral antigens or viral nucleic acids in specimens taken from the appropriate site.
2. Culture of infectious viruses from the appropriate sites.
3. Serological tests to detect specific antiviral antibodies.
4. Cytological or histological examination of cells from the site of infection in those viral infections in which a characteristics CPE is produced.
Clinical Specimens and Sample Collection
For diagnosis of coronavirus, the following specimens are taken:
1. Respiratory materials including nasopharyngeal swabs, oropharyngeal swabs, sputum, etc.
2. Rectal swab & stool
3. Tissue from biopsies or autopsy including those from lungs
5. Urine sample
6. Serum for serological testing
Transportation and Storage of Specimens
• For storage: Specimens can be stored for 5 days at 4°c and for 6 days at -20°c.
• For transportation: Virus transport media(VTM) are used to transport a small volume of the fluid specimens, small tissues & scrapings & swabs specimens, especially when contaminated with microbial flora is expected.
• Some VTM are Hanks balanced salt solution, Stuart’s medium, Eagle’s tissue culture medium, etc.
Detection of Corona Virus
1. Isolation of Virus
The isolation and cultivation of coronavirus taken from specimens is an important step in the diagnosis of coronavirus. The novel coronavirus (SARS-CoV-2) is mainly cultivated in the Vero cell line which are one of the most common mammalian continuous cell lines used in the culture of SARS-CoV-2. It was extracted from the kidney of an African green monkey.
2. Serological Test
The serological test refers to the test involve virus detection, quantifying viral antigens & confirming the presence of the virus or specific antiviral antibodies. There are various types of serological test done for diagnosis of coronavirus:
Complement Fixation test
3. RNA Detection
As coronavirus is an RNA virus so performing Real-time Reverse transcription PCR (rRT-PCR) confirmed the coronavirus RNA in the respiratory secretions & even in the stool samples of patients.
The use of Real-time Reverse transcription (rRT-PCR) assays for the in-vitro qualitative detection of 2019-Novel coronavirus (SARS-CoV-2) in respiratory specimens and sera.
4. Electron Microscopy
Specimens collected from patients are observed under an electron microscope which shows petal-shaped projections that are widely spaced on the outer surface of the envelope etc, Which indicates the presence of coronavirus.
Novel Coronavirus, SARS-CoV-2 and COVID-19 (Updated 2020)
• A recent cluster of pneumonia cases in Wuhan, China was caused by a novel beta coronavirus, the 2019 novel coronavirus (SARS-CoV-2).
• According to the World Health Organization (WHO), the disease caused by Novel Coronavirus, 2019-nCoV (SARS-CoV-2) is now officially called COVID-19.
• Data collected and analyzed from patients using Real-time PCR and Next Generation Sequencing identified it to be a virus of the family of coronaviridiae, genus, coronavirus, a novel beta coronavirus, SARS-CoV-2.
• Its occurrence has raised questions into the genetic relationship and similarity to SARS-CoV of 2003 considering that they both occurred in China and in areas that are of close proximity. SARS-CoV was first reported in Guangdong province, which borders Hong Kong, and 2019-nCoV in Wahun, Town of China as well.
• From data and reports by various organizations including the CDC and WHO indicate that the difference between these two infections is the severity and contagiousness rates, with SARS-CoV being severe as compared to the SARS-CoV-2, but SARS-CoV-2 being more contagious with high rates of infectivity and spread (https://www.pulselive.co.ke/bi/tech/the-wuhan-coronavirus-and-sars-belong-to-the-same-family-but-experts-say-there-are/mhb8zw9) as compared to SARS-CoV.
• Factors like a transmission from an animal to person and person-to-person and nosocomial spread have been the routes of consideration with more reports leaning to an animal to person transmission considering first sight of infectivity was a wet market and person-person transmissions, but yet to be verified.
• Traveling has enhanced the spread of the virus to various countries including Korea, Japan, Taiwan Malaysia, USA, and Australia with great concern about an epidemic outbreak of this specific virus.
• This occurrence comes after reported cases of the same virus occurrence in Research that has been done from 31st Dec 2019 to 4th Jan 2020 has revealed new data into the pathology of the virus.
• In the past two decades, we have seen three variants of coronavirus emerging causing serious epidemic diseases of the respiratory tract system and this an indication that this virus continues to impose continuous threats to human health and affecting the economy as they continue to emerge unexpectedly, spread easily with catastrophic consequences.
What is Coronavirus?
• Coronaviruses belong to the family coronaviridae and are enveloped, positive-sense, single-stranded RNA viruses. they are round and sometimes pleiomorphic with an 80-120nm diameter
• The coronavirus genome is approximately 31 kb, making these viruses the largest known RNA viruses yet identified.
• They are respiratory viruses classified under family: Coronaviridae and Coronavirus as the genus name.
• There are now 7 types of coronaviruses that have been identified by the CDC, which includes:
• Common human coronaviruses
1. 229E (alpha coronavirus)
2. NL63 (alpha coronavirus)
3. OC43 (beta coronavirus)
4. HKU1 (beta coronavirus)
• Other human coronaviruses
5. MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS)
6. SARS-CoV (the beta coronavirus that causes a severe acute respiratory syndrome, or SARS)
7. 2019 Novel Coronavirus (SARS-CoV-2)
• The most common coronaviruses among humans are 229E, NL63, OC43, and HKU1 and some can evolve and cause human diseases, becoming new human coronaviruses.
• Three recent examples of these are SARS-CoV-2, SARS-CoV, and MERS-CoV.
The Novel Coronavirus, COVID-19
• 2019 Novel Coronavirus (SARS-CoV-2) is a virus (more specifically, a coronavirus) identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China (https://www.cdc.gov/coronavirus/2019-ncov/about/index.html).
• Similarities of clinical features between SARS-CoV-2 and previous betacoronavirus infections have been noted with most patients presented with fever, dry cough, dyspnoea, and bilateral ground-glass opacities on chest CT scans.
• These features of SARS-CoV-2 infection bear some resemblance to SARS-CoV and MERS-CoV infections, in their routes of transmission, pathologies, and manifestations, and even in the forms of treatment that have initially been used to reduce the symptoms of patients.
• The virus has been noted to have a long incubation period of 1-14 days, with patients remaining asymptomatic until the occurrence of the disease, producing severe upper and lower respiratory tract infections.
• The virus though has been greatly associated with SARS-CoV since it has a range of similarities in symptom manifestations and the initial steps taken in detecting and identifying the virus involved those applied during the SARS-CoV outbreak in 2003.
• This is a major factor because the virus is novel and a lot more research is yet to uncover its pathologies, including the immunological responses that increased the hyperproduction of cytokines into the patients’ plasma.
• Cases of patients presented with this viral infection have symptoms ranging from acute illness to progressively severe respiratory illnesses associated with pneumonia.
Risk Factors of COVID-19 caused by SARS-CoV-2
From the data collected by the CDC, the persons at risk are
1. Elderly persons above the age of 50 persons with underlying diseases like diabetes, Parkinson’s disease, cardiovascular diseases.
2. Demographically, it can also be stated that the persons living in China around Wahun town are most at risk, especially those working and shopping from Animal markets within the localities; and persons traveling into and out of Wahun.
3. Hospital-acquired infection- Health care workers caring for patients with the 2019-nCoV (https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30183-5/fulltext)
Clinical Features (Symptoms) of COVID-19 caused by SARS-CoV-2
Figure: Signs and Symptoms of COVID-19 caused by SARS-CoV-2
Manifestations are mild and/or progressive in some cases to severe symptoms that can eventually lead to death. These include
1. Fever associated with flu-like symptoms of coughing, headache
2. Upper or/and lower respiratory tract symptoms associated with shortness of breath and breathing difficulties
3. Diarrhea after the virus colonizes the epithelial lining of the gastrointestinal tract
4. General body weakness and myalgia (fatigue)
5. In severe cases, individuals elicit symptoms of pneumonia with abnormal chest CT, hemoptysis, lymphopenia, associated with complications of severe acute respiratory distress syndrome, acute cardiac injury, kidney failure and eventually, death.
Incubation Period of COVID-19 caused by SARS-CoV-2
• 1-14 days after exposure (Most cases remain asymptomatic during this period)
Transmission of COVID-19 caused by SARS-CoV-2
• Animal to Human transmission (Examples: camels, cattle, cats, and bats)
• Human to Human transmission (Via blood, stool, urine, saliva, semen, etc.)
• Nosocomial transmission from infected patients to caregivers and health care workers
NOTE: The exact way the virus is spread is not fully known. With similar coronaviruses (MERS and SARS) person-to-person spread is thought to have happened mainly via respiratory droplets produced when an infected person coughs or sneezes, similar to how influenza and other viruses that cause respiratory illness spread. There also may be some spread when a person touches a surface or object that has a virus on it and then touches his or her own mouth, nose, or possibly their eyes (www.cdc.gov).
Pathophysiology of COVID-19 caused by SARS-CoV-2
• Initially, coronaviruses remained obscure primarily because there were no severe human diseases that were attributed to it since it was known to cause the common cold.
• But since 2003, after the occurrence of SARS-CoV in 2003, in China and MERS-CoV, in 2012 in Saudi Arabia, and now the outbreak of Pneumonial clustered Novel Coronavirus (2019-nCoV), has put this virus on the map, significantly labeling coronavirus as an ‘Emerging Pathogen’.
• The coronavirus envelope, under an electron microscope, appears to be crowned by a characteristic ring of small bulbous structures.
• This morphology is formed by the viral spike (S) peplomers, which are type 1 glycoproteins that populate the surface of the virus and determine host tropisms, and other structures like the Membrane (M), a protein that spans the membrane three times and has a short N-terminal ectodomain and a cytoplasmic tail; and envelope protein (E), a highly hydrophobic protein and the nucleocapsid.
• These viral spike proteins are known to play a role in the pathogenesis of coronaviruses by inducing neutralizing antibodies and mediating viral fusion of the vial cell envelope with the host cell membrane.
• They are also capable of hemagglutination. this immensely contributes to the infectivity and progressiveness of the virus which spirals to Severe Respiratory illnesses and pneumonia.
• Also, considering the virus’s long incubation period of 1-14 days (according to China’s National Health Commission), the period is contagious thus enhancing the rate of spread and infection to other individuals through contact and exposure to infected aerosols.
• During the incubation period, the virus remains asymptomatic upon which the host immune system responds by activating antibody production which induces cytokine production, causing severe inflammation of the lungs causing inflammatory-lung injury with severe pneumonia and other upper and lower respiratory infections associated with fever, headaches, coughing, hemoptysis, myalgia, and renal failure.
• This increases rapidly the mechanisms of immunopathogenesis and, unfortunately, causes pulmonary tissue damage, functional impairment, and reduced lung capacity.
• Early investigations into the 2019-nCoV, indicated a cascade of cytokines present in plasma of most patients i.e production of cytokines or chemokines in the acute phase of the illness, plasma cytokines and chemokines (IL1B, IL1RA, IL2, IL4, IL5, IL6, IL7, IL8 (also known as CXCL8), IL9, IL10, IL12p70, IL13, IL15, IL17A, Eotaxin (also known as CCL11), basic FGF2, GCSF (CSF3), GMCSF (CSF2), IFNγ, IP10 (CXCL10), MCP1 (CCL2), MIP1A (CCL3), MIP1B (CCL4), PDGFB, RANTES (CCL5), TNFα, and VEGFA, which were measured using Human Cytokine Standard 27-Plex Assays panel and the Bio-Plex 200 system (Bio-Rad, Hercules, CA, USA).
• The pathophysiology of this novel virus(2019-nCoV) along with that of SARS-CoV and MERS-CoV are all yet to be understood.
Diagnosis of COVID-19 caused by SARS-CoV-2
Specimens as per the WHO recommendation:
1. Respiratory materials including Nasopharyngeal and oropharyngeal swabs, sputum and/or endotracheal aspirate or bronchoalveolar lavage in patients with more severe respiratory disease.
2. Tissue from biopsies or autopsy including those from the lungs
3. Whole blood
4. Urine samples
5. Serum for serological testing, acute sample and convalescent sample (2-4 weeks after acute phase)
NB: Collection of the samples should be done with CAUTION and all samples regarded as potentially infectious with regard to strict adherence to Infection Prevention and Control guidelines.
Observing patient symptoms. This includes; fever, headaches, myalgia, sneezing, and coughing. If the patients meet the case definition of the suspected COVID-19, he/she should be screened for the virus with PCR.
Currently, the diagnostic tests available are aiming at conventionally detecting the causes of pneumonia early, to support disease control activities and to work with reference Labs that can perform pan coronavirus detection and directed sequencing. (WHO/2019-nCoV/laboratory/2020.3). The recommended diagnostic methods include;
1. Isolation of the virus in human airway epithelial cells.
2. Use of pan-coronavirus assay for amplification
3. followed by, Real-time Reverse Transcription (RT)-PCR assay has been designed to detect sequences of the virus
4. Whole-genome sequencing and genome analysis by bioinformatics including phylogenic tree construction to distinguish the characteristics of SARS-CoV-2 from other coronaviruses.
5. Serological testing to confirm immunological responses to the specific virus, SARS-CoV-2 for example, cytokine identification, measurement, and quantification.
Click here to view the complete genome of Wuhan seafood market pneumonia virus isolate Wuhan-Hu-1.
Click here to view the Phylogenic Tree of 27 genomes sampled between Dec 2019 and Jan 2020.
Treatment and Prophylaxis of COVID-19 caused by SARS-CoV-2
• Symptomatic treatment of the disease.
• The virus currently has no specific drug of choice for treatment but the first cases reported with severe illnesses were administered with corticosteroids ((methylprednisolone 40–120 mg per day))to reduce inflammatory induced lung injury, low-to-moderate quantities to patients with Acute Respiratory Syndrome (thelancet.com).
• For severe cases, treatment should include care to support vital organ functions.
• Currently, there are no antiviral drugs that have effective treatment for Coronaviruses.
Prevention and Control of COVID-19 caused by SARS-CoV-2
• Maintaining basic hand and respiratory hygiene.
• Avoid close contact, with anyone showing symptoms such as coughing and sneezing.
• Avoid contact with farm or wild animals such as bats.
• The consumption of raw or undercooked animal products should be avoided.
• People can stay at home if they are sick.
• Cleaning and disinfecting frequently touched objects and surfaces.
NOTE WITH CAUTION: Detection of a possible case of an emerging pathogen causing severe acute respiratory disease should be reported immediately to local, sub local and national health care authorities for immediate action. This includes animal and human infections.
Also, handling of such patients should be done with high precaution with safe clothing including gloves and face masks, and possible quarantine and exclusion protocols followed, immediately.