WHAT IS THE CORONAVIRUS?

Medically Reviewed by Dr. Sony Sherpa (MBBS) and Updated on August 17, 2021

This article is continuously updated.

As the COVID-19 pandemic continues to warrant global implementation of prevention measures, much has been gathered about the infectious disease responsible for the deaths of millions. 

Signs, symptoms, complications and mortality risks are discussed below alongside public prevention tips.

What is COVID-19?

COVID-19 stands for ‘coronavirus disease 2019’ and refers to a respiratory disease caused by SARS-COV-2, a virus of the coronavirus family.[1] SARS-COV-2 was discovered at the beginning of 2020 as being the cause of a sudden pneumonia outbreak, which evolved into the current COVID-19 virus pandemic. The virus targets the lower respiratory tract, resulting in a dry cough and shortness of breath.

Scientists are still investigating the characteristics of SARS-COV-2 and how it differs from other coronaviruses. One thing all viral strains in this family have in common is causing respiratory symptoms. Other coronaviruses include the common cold, MERS (Middle Eastern Respiratory Syndrome) and SARS (Severe Acute Respiratory Syndrome) [2]. SARS-COV-2 appears to be most closely related to SARS[3] (SARS-COV-1), sharing up to 79.6% homology[4].

Brief History of the COVID-19 Pandemic

2020 certainly began with a bang; particularly for those in Wuhan, China, where the virus was first discovered. The events leading up to the pandemic are summarized as follows:

• Dec 31^st 2019. The first several cases of ‘pneumonia of unknown origins’ were officially reported, just before the Chinese New Year celebrations[5]. In response to the sudden outbreak, China issued that the large city be locked down and quarantined to prevent the spread of infectious media as much as possible.
• Early January 2020. After much high-speed analysis, it was shortly announced that the pneumonia was caused by a novel coronavirus.
• Jan 11. The WHO announced that it had received genetic sequences from China for the novel coronavirus.
• Jan 30^th. WHO officials declared the outbreak to be a “public health emergency of international concern”[6], placing it in the same risk category as Ebola, Zika virus, H1N1 and poliomyelitis[7].
• Feb 11. The disease caused by the novel coronavirus was named COVID-19 by WHO officials, with the actual virus being named SARS-COV-2.
• COVID-19 virus infections began to crop up in multiple countries outside of China.
• Early March. The World Health Organization (WHO) announced that the viral outbreak was quickly reaching pandemic proportions, with confirmed cases already surpassing 100,000 worldwide. Warning statements, prevention measures and funding were quickly organized and issued on a global scale in response to the rapid spread of the virus.[8]
• Since this time, nearly all countries across the globe have implemented precautionary measures, including lockdowns that restrict travel, facemasks and social distancing.
• A lot of funding went into SARS-COV-2 and COVID-19 research, propelling the development of several vaccines.
• Several SARS-COV-2 strain variants have been isolated, increasing the need for further research and better prevention strategies.

Researchers at Oxford University have been mapping the stringency of lockdowns globally. A world map of the results can be viewed here.

What Caused the Original Coronavirus Outbreak?

Since most other types of coronavirus have been traced back to animals, such as wild cats for SARS and camels for MERS, the COVID-19 virus was long suspected to have an animal origin. This was confirmed to be true; however the precise origins are still a matter of debate.

Bats appear to be natural vectors for coronaviruses. Not surprisingly, genomic analysis of the virus confirms that it was likely to have mutated in horseshoe bats[9]. As these bats are not native to Wuhan, it was likely transmitted to an unknown intermediate animal before encountering humans.[10] 

Officials traced the initial outbreak back to the Huanan Seafood Wholesale Market; a large meat market in Wuhan that sells livestock, poultry and exotic wild animals (in addition to seafood).[11] SARS-COV-2 was identified in animal products being sold at the market. Given the evidence, it is most likely that a person or animal product was exposed to a bat containing the virus at some point prior to the outbreak.

Research is being conducted on animals able to contract the virus to piece together the true viral origins. So far, many animals appear to be possible viral vectors including dogs, cats, fruit bats, ferrets, hamsters, tigers, lions, mink and rhesus monkeys.

The Lab-Leak Hypothesis

Could the pandemic have been caused by a lab leak? Given the evidence, SARS-COV-2 is not considered the result of a lab accident.

A few skeptics have suggested that the virus was accidentally leaked from a lab in Wuhan. Several countries, including the US, took up the investigation of the Wuhan Institute of Virology as being the potential origin[12] [13]. The findings are currently inconclusive.

Many rumors about the institute have been circulating media, referred to collectively as the “lab-leak hypothesis.”

Suspicions initially arose when it was found out that scientists at the institute specialize in the study of coronaviruses and were working on a bat-derived virus similar to SARS-COV-2, known as RaTG13.

RaTG13 and SARS-COV-2 appear to share a genetic overlap of up to 96%. Experts stipulate that it would have taken roughly 50 years for SARS-COV-2 to have evolved from RaTG13. [14] The lab has had RaTG13 stored in freezers since 2013, making the chances of accidental high-speed mutation very slim. The genetic similarity is most likely explained by a common ancestor, rather than rapid viral evolution.

Three lab members have subsequently been suspected to have been infected with the virus in Dec 2019, just before the initial Wuhan outbreak. The Wuhan Institute of Virology asserts that the staff tested negative for SARS-COV-2 antibodies, suggesting that if workers were fighting an infection, it was not likely to be related to the outbreak.[15]

May 2021. Another investigation of the lab-leak hypothesis has been initiated by US President Joe Biden.[16] [17] The scientific community remains divided on whether the virus originated in a lab or not, spurring Biden’s decision to do so[18]. The case is on hold until more evidence comes to light.

Signs, Symptoms & Causes: What We Know So Far About COVID-19

SARS-COV-2 primarily infects the lower respiratory tract. COVID-19 is an acute respiratory disease caused by SARS-COV-2. Infectious material can also be found in the cells along the upper tract, resident macrophages and lymph glands lining the respiratory tract.

Main symptoms of COVID-19 include[19]:

• Pneumonia or shortness of breath
• A dry cough
• Fever
• Fatigue

The initial fever at the time of symptom onset subsided on average in 7 days, with a range of 3-10 days.

96% tested negative for active infection within 30 days after symptom onset.

Not everyone who gets infected experiences symptoms. Asymptomatic individuals are still infectious and capable of spreading COVID-19.

Uncommon Symptoms. Unlike symptoms of SARS and MERS infections, sneezing, a runny nose, a sore throat, headaches and diarrhea were less common in COVID patients. Of these, headaches and digestive issues appear more frequently.

Other Potential Infection Sites. It is likely that COVID has the potential to infect the gut, as evidenced by infectious viral fragments found in stool samples. Preliminary research suggests the virus may infect nearly all human cells through interactions with ACE2 receptors.

Viral Complications

Some individuals may contract severe respiratory complications during active SARS-COV-2 infection, requiring hospitalization and the use of oxygen devices to stabilize their condition. An early report in China of over 72 000 infected patients reveals that up to 14% of those who contract SARS-COV-2 will land in this position, while 81% of cases were classified as mild.[20]

Fibrosis (scarring) of the lungs is a common complication in the majority of those with COVID-19, including asymptomatic or mildly symptomatic individuals. This serves to reduce respiratory function and may be a cause of chronic pneumonia in severe post-COVID cases.

Chronic fatigue, sleep difficulties, and anxiety or depression were other frequent viral complications.[21] Further complications from active infection include severe manifestations of symptoms, such as[22]:

• Rapid weight loss
• Muscle weakness, pain and wasting
• Dehydration
• Migraines
• Dizziness or disorientation
• Heart arrhythmia or palpitations
• Reduced cognition
• Difficulty concentrating
• Chest or stomach pain
• Rash
• Hormonal disruptions resulting in menstrual changes
• Loss of taste and/or smell
• Hair loss

Hospitalization and severe respiratory distress may also induce PTSD in some cases.

Long COVID-19 also referred to as post-COVID-19, is the most common post-viral complication in which symptoms of COVID-19 chronically persist long after the infection has subsided. “Long Haulers” tend to experience combinations of the above symptoms for prolonged periods of time post-infection, with differing degrees of severity. Mild or asymptomatic infections can also precipitate post-COVID syndrome.[23]

According to the current understanding of underlying mechanisms, contracting COVID-19 is very likely to increase the risk for the majority of chronic diseases including:

• Atherosclerosis
• Severe blood clotting (coagulopathy) and heart disease[24]
• Hemolytic anemia[25] [26]
• Mood disorders
• Delirium and dementia
• Autoimmune conditions[27]
• Diabetes or insulin resistance
• Stroke and other ischemic conditions
• Kidney disease

Rare Complications. A tiny percentage of confirmed cases appear prone to cardiac, lung, and kidney damage as a result of contracting the virus. Acute respiratory failure, septic shock, and/or multiple organ damage and failure following a large inflammatory cytokine storm are thought to have caused fatality in the most severe cases.[28]

SARS-CoV-2 Incubation Time

Viral incubation is the time it takes for a virus to replicate until peak infectious symptoms appear. An infected person can be contagious even during the incubation period[29].

The average incubation time of COVID-19 currently recorded seems to be around 5-10 days. Some individuals display symptoms within a day or while in others it may be as long as 14 days before flu-like symptoms emerge.[30]

It typically takes about 8 days after incubation for the patient to begin having trouble with their breathing.

SARS-COV-2 Carrier Types

Since early on in the pandemic, it has been noted that not everyone infected with SARS-COV-2 develops symptoms of COVID-19 and of those that do, the severity of symptoms varies widely.

Accordingly, there are four types of SARS-COV-2 carriers:

1. Asymptomatic carriers. Infected persons who do not display symptoms.
2. Presymptomatic carriers. Infected persons in the viral incubation phase, prior to symptom onset.
3. Paucisymptomatic carriers. Infected persons with only a few symptoms.
4. Symptomatic carriers. Infected persons with symptoms.

All carrier types are able to transmit the virus and spread COVID-19. While the risk may be reduced, all who get infected are prone to viral complications, including organ damage and post-COVID-19 symptoms.

Viral Shedding

Active viral shedding from the respiratory tract averages 17-20 days, depending on infection severity. Nevertheless, viral shedding varies from individual to individual, ranging from 3 to 111 days according to available data.

Infectious particles could be cultured from samples for up to 20 days after symptom onset. Viral RNA from respiratory sources may be present for 1-4 months after symptom onset, however it is unlikely to be infectious after 20 days.[31]

Symptomatic individuals appear to have a higher level of viral shedding than those with mild symptoms or without symptoms. In spite of this, viral shedding may be prolonged in anyone, regardless of the carrier type[32] [33]. The risk of transmission was shown to be low as a result of viral shedding from mildly symptomatic or asymptomatic individuals with late-phase COVID-19.[34]

Sites of viral shedding

• The highest rates of viral shedding have been detected from the respiratory tract so far.
• Feces may also harbor active viral particles. Urinary viral shedding appears low in infected persons, with an increased prevalence in those with moderate to severe chronic disease.[35]
• Sweat and skin may be prone to viral shedding, but are still under investigation.

Factors that may reduce viral shedding time

• Patients with higher albumin levels had reduced viral shedding times of 1-2 days compared to patients with lower levels.
• Starting antiviral treatment within the first 7 days of symptom onset also lowered viral shedding times by as much as 3 days on average.

Factors that may increase viral shedding time

• Coronary Heart Disease may be a risk factor for prolonged viral shedding.
• Viral shedding time increased with age, being roughly 34 days for those over 60 years of age and 22 for those under 40.[36]
• Reduced immune function and white blood cell count may increase disease severity and viral shedding time.[37]
• Studies have confirmed a lower rate of viral clearance in elderly and immune-compromised individuals.

COVID-19 Diagnostics

Currently, available swab tests are unable to accurately assess infectivity, SARS-COV-2 antibody levels, and viral immunity, as they give rise to false positive and false negative results[38].

Blood testing of multiple immunologic and vascular parameters is likely to prove more useful in diagnosing COVID-19. Markers for SARS-COV-2 and COVID-19 have yet to be identified and are a current area of active study.

CT scans may reveal fibrosis of the lungs and may be useful in diagnostics.

COVID-19 Statistics and Mortality: Who is at the Highest Risk?

It’s important to emphasize that all diseases and infections have the potential to be deadly, even the common cold! As of the end of July 2021, there have been over 194 million reported cases of COVID-19 worldwide and more than 4.16 million deaths (viz. Google), averaging a mortality rate of 2.14%.

The chances of mortality in healthy individuals contracting COVID are very slim and likely not a cause for concern. Oxygen administration has been shown to effectively stabilize many in critical condition after having contracted the infection.

The majority of COVID-related deaths have been attributed to those with weaker immune systems, immune complications, and comorbidities. The elderly are the most susceptible. Limited global evidence suggests a higher mortality rate in men as opposed to women, however, infection rates were equal.[39]

Heart disease is one of the worst comorbidities, increasing the risk of mortality in the infected by 5-10 times[40]. Having anemia or low hemoglobin levels may substantially exacerbate the risk of multiple organ failure and COVID-19 mortality.[41] 

COVID-19 itself increases the risk of reinfection with SARS-COV-2[42], particularly with respect to strain variants. In this respect, COVID-19 counts as a comorbidity that may exacerbate infection severity and disease outcomes. Nonetheless, those who successfully recover have increased resistance to infection[43].

Other comorbidities that may increase infection time, disease severity, and complication risk include:

• Anemia
• Obesity
• Hypertension
• Autoimmune diseases
• HIV/AIDS
• TIA’s and other ischemic conditions
• Mental health disorders
• Diabetes and metabolic syndromes
• Hypertension
• Cancer[44]

This list is likely not exhaustive. Research suggests that just about any chronic inflammatory lifestyle disease may worsen prognosis.

COVID-19 versus Influenza

To put the above statistics into perspective, roughly 3-5 million people become infected globally with the common flu (either influenza A or B), and of that, up to 650000 people die every year as a result. The ones who are at risk of fatality are, once again, the immune compromised.[45]

By comparison, COVID-19 has a much lower mortality rate than common types of influenza. However, it appears to be much more infectious. In spite of having a lower mortality rate, COVID-19 has nearly claimed more lives already than the average number of people who contract influenza annually. It is imperative that strict precautionary measures remain until a foolproof treatment has been developed.

6 Tips to Reduce COVID-19 Risk and Lower SARS-COV-2 Viral Spread

The following tips can help to reduce the spread of infections in general, including SARS-COV-2, and may reduce the risk of contracting infectious diseases such as COVID-19.

1. Adhere to Prevention Measures

Compliance is king. Communities that do not adhere to prevention measures such as social distancing and mask-wearing are at a substantially increased risk of transmission. Make sure you are well-acquainted with current prevention measures and do your best to implement them as strictly as possible.

Additionally, getting vaccinated against SARS-COV-2 is highly recommended by health authorities.

When is COVID-19 going to end?

It’s not a secret that most people are fed up with the strict prevention measures being enforced by governments globally. Many are wondering when it will end and when life will go back to “normal.”

Most experts agree that life is likely to never return completely to the pre-COVID era. This pandemic has shaped the outlook for future outbreaks, marking it as a turning point in human history. While restrictions may be eased in response to reaching vaccine targets, they may return at any moment without warning when the next public health crisis hits.

A few prevention measures are also likely to become a part of everyday life moving forward. Many countries and businesses globally are making vaccinations mandatory in an effort to end lockdown restrictions. It is also possible that wearing masks and maintaining stringent hygiene practices will continue to be enforced to reduce the spread of other infectious diseases.

2. Avoid Contact with Bats, Other Wild Animals and Strays

As the virus is suspected to have originated from bats and bats are known to be natural coronavirus vectors (for more than 1000 of these viruses), it is best to avoid them!

Other wild animals are being investigated for their potential to promote SARS-COV-2 mutation. These too ought to be avoided to reduce the risk of spreading the infection.

Cats and dogs, as well as other domestic animals, are also potential vectors for infectious diseases. Keeping your pets healthy and avoiding direct contact with stray animals may help in this regard.

3. Focus on Supporting Your Immune System

Something worth noting about all viral infections is that antibiotics don't work or help. The majority of successful antiviral treatments revolve around enhancing immune function. Therefore, if you want to avoid the common cold or any virulent flu, focus on boosting your immune system!

Here are some great suggestions:

• Make sure you get adequate sleep each night (7-9hours)[46].
• Supplement with Vitamin C and zinc[47].
• Keep hydrated.
• Take advantage of the many herbal teas the East has to offer, with their immune-enhancing properties[48] [49].
• Adequate nutrition is vital for optimal immune function[50]. Ensure to meet your daily nutritional requirements by consuming a wide variety of fresh fruits and vegetables. According to one study, five or more portions per day significantly improves antibody production.[51]
• Evidence suggests that the phytochemicals hesperidin and rutin (including variants quercetin, kaemferol, and luteolin) may possess anti-SARS-COV-2 properties[52]. Foods high in these nutrients are safe to consume and are known to promote wellness. They include citrus fruits, peppermint^[53] and other herbs, berries, black tea, capers, olives, and asparagus.
• Moderate alcohol, sugar, and salt intake.
• Have plenty of fun, rest, and do not stress!
• Keep consistent with exercise at a moderate intensity[54]. Avoid exercise if immune compromised.

4. Keep Clean

This is a prime prevention measure that cannot be stressed enough. Strict hygiene practices are important for slowing the spread of all infectious material. Keeping yourself, your hands and your environment clean will go a long way towards this aim.

Surfaces are often contaminated with a cesspool of different organisms. Do your best to avoid touching surfaces in public places. It can be a good idea to carry around a pack of tissues, gloves or some sort of hand sanitizer in your bag in the event that you need to do so.

If you find yourself coughing or sneezing, do your best to prevent the spread of germs. A spare facemask is ideal in this situation. You also ought to avoid touching your face, mouth, and eyes as well as the faces of other people.

Infectious particles may also be transmitted through plumbing systems. Drains should be kept clean, bathrooms disinfected, and any strange smells, organismal growth, and damp should be dealt with as soon as possible to avoid the potential spread of infection. 

5. Thoroughly Clean and Cook Your Food

Generally, cooking food is safer than consuming raw foods that may have been exposed to viral particles. Nonetheless, raw foods such as fruit are essential for health and therefore ought to be washed properly before consumption.

If you are going to eat animal products, especially wild animal products, make sure they are thoroughly cooked to ensure no potential viral RNA remains intact.

6. Test Yourself if You Suddenly Contract Symptoms

If you suddenly come down with respiratory symptoms and do not feel well, then you need to report yourself to a healthcare provider immediately. Getting tested may help you to receive immediate treatment and get a prompt diagnosis, as well as help officials, to track the course of the pandemic.

Conclusion

While hope is on the horizon with regard to prevention, the world is still far from finding a cure for COVID-19. The current pandemic highlights just how vulnerable we are to infectious diseases and as a result, life is likely to never return to the way it was before.

The efforts of scientists working to resolve the current global health crisis will be carried forward, improving our ability to manage similar events in the future. In the meantime, it is important to maintain prevention measures, practice good hygiene, and do one’s best to support their health and well-being.

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