What to know about coronaviruses
Coronaviruses are types of viruses that typically affect the respiratory tracts of birds and mammals, including humans. Doctors associate them with the common cold, bronchitis, pneumonia, and severe acute respiratory syndrome (SARS), and they can also affect the gut.
These viruses are typically responsible for common colds more than serious diseases. However, coronaviruses are also behind some more severe outbreaks.
Over the last 70 years, scientists have found that coronaviruses can infect mice, rats, dogs, cats, turkeys, horses, pigs, and cattle. Sometimes, these animals can transmit coronaviruses to humans.
Stay informed with live updates on the current COVID-19 outbreak.
Most recently, authorities identified a new coronavirus outbreak in China that has now reached other countries. It has the name coronavirus disease 2019, or COVID-19.
In this article, we explain the different types of human coronaviruses, their symptoms, and how people transmit them. We also focus on three particularly dangerous diseases that have spread due to coronaviruses: COVID-19, SARS, and MERS.
What is a coronavirus?
Share on PinterestCovering the mouth when sneezing may help stop the spread of coronaviruses.
Researchers first isolated a coronavirus in 1937. They found a coronavirus responsible for an infectious bronchitis virus in birds that had the ability to devastate poultry stocks.
Scientists first found evidence of human coronaviruses (HCoV) in the 1960s in the noses of people with the common cold. Two human coronaviruses are responsible for a large proportion of common colds: OC43 and 229E.
The name “coronavirus” comes from the crown-like projections on their surfaces. “Corona” in Latin means “halo” or “crown.”
Among humans, coronavirus infections most often occur during the winter months and early spring. People regularly become ill with a cold due to a coronavirus and may catch the same one about 4 months later.
This is because coronavirus antibodies do not last for a long time. Also, the antibodies for one strain of coronavirus may be ineffective against another one.
Cold- or flu-like symptoms usually set in from 2–4 days after a coronavirus infection and are typically mild. However, symptoms vary from person-to-person, and some forms of the virus can be fatal.
Sneezing, runny nose, fatigue, cough, fever in rare cases sore throat exacerbated asthma Scientists cannot easily cultivate human coronaviruses in the laboratory unlike the rhinovirus, which is another cause of the common cold. This makes it difficult to gauge the impact of the coronavirus on national economies and public health.
There is no cure, so treatments include self-care and over-the-counter (OTC) medication. People can take several steps, including:
resting and avoiding
drinking enough water
avoiding smoking and
ibuprofen, or naproxen for
pain and fever
using a clean humidifier
or cool mist vaporizer
A doctor can diagnose the virus responsible by taking a sample of respiratory fluids, such as mucus from the nose, or blood.
Coronaviruses belong to the subfamily Coronavirinae in the family Coronaviridae.
Different types of human coronaviruses vary in how severe the resulting disease becomes, and how far they can spread.
Doctors currently recognize seven types of coronavirus that can infect humans.
Common types include:
229E (alpha coronavirus)
NL63 (alpha coronavirus)
OC43 (beta coronavirus)
HKU1 (beta coronavirus)
Rarer strains that cause more severe complications include MERS-CoV, which causes Middle East respiratory syndrome (MERS), and SARS-CoV, the virus responsible for severe acute respiratory syndrome (SARS).
In 2019, a dangerous new strain called SARS-CoV-2 started circulating, causing the disease COVID-19.
Limited research is available on how HCoV spreads from one person to the next.
However, researchers believe that the viruses transmit via fluids in the respiratory system, such as mucus.
Coronaviruses can spread in the following ways:
Coughing and sneezing without covering the mouth can disperse droplets into the air.
Touching or shaking hands with a person who has the virus can pass the virus between individuals.
Making contact with a surface or object that has the virus and then touching the nose, eyes, or mouth.
Some animal coronaviruses, such as feline coronavirus (FCoV), may spread through contact with feces. However, it is unclear whether this also applies to human coronaviruses.
The National Institutes of Health (NIH) suggest that several groups of people have the highest risk of developing complications due to COVID-19. These groups include:
people aged 65 years or older
women who are pregnant
Coronaviruses will infect
most people at some time
during their lifetime.
Coronaviruses can mutate effectively, which makes them so contagious.
To prevent transmission, people should stay at home and rest while symptoms are active. They should also avoid close contact with other people.
Covering the mouth and nose with a tissue or handkerchief while coughing or sneezing can also help prevent transmission. It is important to dispose of any tissues after use and maintain hygiene around the home.
Basic protective measures against the new coronavirus
Stay aware of the latest information on the COVID-19 outbreak, available on the WHO website and through your national and local public health authority. COVID-19 is still affecting mostly people in China with some outbreaks in other countries. Most people who become infected experience mild illness and recover, but it can be more severe for others. Take care of your health and protect others by doing the following:
Wash your hands frequently
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 social distancing
Maintain at least 1 metre (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 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.
Practice respiratory hygiene
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 virus. By following good respiratory hygiene you protect the people around you from viruses such as cold, flu and COVID-19.
If you have fever, cough and difficulty breathing, seek medical care early
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 spread of viruses and other infections.
Stay informed and follow
advice given by your healthcare provider
Stay informed on the latest developments about COVID-19. Follow advice given by your healthcare provider, your national and local public health authority or your employer on how to protect yourself and others from COVID-19.
Why? National and local authorities will have the most up to date information on whether COVID-19 is spreading in your area. They are best placed to advise on what people in your area should be doing to protect themselves.
Protection measures for persons who are in or have recently visited (past 14 days) areas where COVID-19 is spreading
sFollow the guidance outlined above.
sStay at home if you begin to feel unwell, even with mild symptoms such as headache and slight runny nose, until you recover. Why? Av oiding contact with others and visits to medical facilities will allow these facilities to operate more effectively and help protect you and others from possible COVID-19 and other viruses.
sIf you develop fever, cough and difficulty breathing, seek medical advice promptly as this may be due to a respiratory infection or other serious condition. Call in advance and tell your provider of any recent travel or contact with travelers. Why? Calling in advance will allow your health care provider to quickly direct you to the right health facility. This will also help to prevent possible spread of COVID-19 and other viruses.
In 2019, the Centers for Disease Control and Prevention (CDC) started monitoring the outbreak of a new coronavirus, SARS-CoV-2, which causes the respiratory illness now known as COVID-19. Authorities first identified the virus in Wuhan, China.
More than 74,000 people have contracted the virus in China. Health authorities have identified many other people with COVID-19 around the world, including many in the United States. On January 31, 2020, the virus passed from one person to another in the U.S.
The World Health Organization (WHO) have declared a public health emergency relating to COVID-19.
Since then, this strain has been diagnosed in several U.S. residents. The CDC have advised that it is likely to spread to more people. COVID-19 has started causing disruption in at least 25 other countries.
The first people with COVID-19 had links to an animal and seafood market. This fact suggested that animals initially transmitted the virus to humans. However, people with a more recent diagnosis had no connections with or exposure to the market, confirming that humans can pass the virus to each other.
Information on the virus is scarce at present. In the past, respiratory conditions that develop from coronaviruses, such as SARS and MERS, have spread through close contacts.
On February 17, 2020, the Director-General of the WHO presented at a media briefing the following updates on how often the symptoms of COVID-19 are severe or fatal, using data from 44,000 people with a confirmed diagnosis:
The Director-General also noted that the risk of serious complications increases with age. According to the WHO, few children get COVID-19, although they are still investigating the reasons for this.
However, while some viruses are highly contagious, it is less clear how rapidly coronaviruses will spread.
Symptoms vary from person-to-person with COVID-19. It may produce few or no symptoms. However, it can also lead to severe illness and may be fatal. Common symptoms include:
fever, breathlessness, cough
It may take 2–14 days for a person to notice symptoms after infection.
No vaccine is currently available for COVID-19. However, scientists have now replicated the virus. This could allow for early detection and treatment in people who have the virus but are not yet showing symptoms.
UN releases US$15 million to help vulnerable countries battle the spread of the coronavirus
UN Humanitarian Chief Mark Lowcock today released US$15 million from the Central Emergency Response Fund (CERF) to help fund global efforts to contain the COVID-19 virus.
The announcement came as the World Health Organization (WHO) upgraded the global risk of the coronavirus outbreak to “very high” – its top level of risk assessment. The WHO has said there is still a chance of containing the virus if its chain of transmission is broken.
The sudden increases of cases in Italy, the Islamic Republic of Iran and the Republic of Korea are deeply concerning. There are now cases linked to Iran in Bahrain, Iraq, Kuwait and Oman, along with cases linked to Italy in Algeria, Austria, Croatia, Germany, Spain and Switzerland.
The UN funding has been released to the WHO and the United Nations Children’s Fund (UNICEF). It will fund essential activities including monitoring the spread of the virus, investigating cases, and the operation of national laboratories.
The WHO has called for US$675 million to fund the fight against coronavirus. There is a window of opportunity to contain the spread of the virus if countries take robust measures to detect cases early, isolate and care for patients, and trace contacts.
Emergency Relief Coordinator and Under-Secretary-General for Humanitarian Affairs, Mark Lowcock said: “We do not yet see evidence that the virus is spreading freely. As long as that’s the case, we still have a chance of containing it.
“But swift and robust action must be taken to detect cases early, isolate and care for patients, and trace contacts. We must act now to stop this virus from putting more lives at risk.
“This grant from the UN’s Emergency Fund will help countries with fragile health systems boost their detection and response operations. It has the potential to save the lives of millions of vulnerable people.”
This is a critical juncture in the outbreak. The focus is on containing COVID-19 by strengthening surveillance, conducting thorough outbreak investigations to identify contacts and applying appropriate measures to prevent further spread.
Tedros Adhanom Ghebreyesus, WHO Director-General, said: “The potential spread of the virus to countries with weaker health systems is one of our biggest concerns. These funds will help support these countries get ready for detecting and isolating cases, protecting their health workers, and treating patients with dignity and appropriate care. This will help us save lives and push back the virus”
UNICEF is leading on preventative actions in communities across the affected countries with risk communication, providing hygiene and medical kits to schools and health clinics and monitoring the impact of the outbreak to support continuity of care, education and social services.
“At this pivotal moment, every effort must be made to push back against the outbreak,” said UNICEF Executive Director Henrietta Fore. “These crucial funds will support our global efforts to bolster weaker health systems and inform children, pregnant women and families about how to protect themselves.”
Since it was launched in 2006, CERF has provided more than $6 billion to over 100 countries and helped hundreds of millions of people.
SARS was a contagious disease that developed after infection by the SARS-CoV coronavirus. Typically, it led to a life threatening form of pneumonia.
During November 2002, the virus started in the Guangdong Province in southern China, eventually reaching Hong Kong. From there, it rapidly spread around the world, causing infections in more than 24 countries.
SARS-CoV can infect both the upper and lower respiratory tracts.
The symptoms of SARS develop over the course of a week and start with a fever. Early on in the condition, people develop flu-like symptoms, such as:
Pneumonia, a severe lung infection, usually develops. At its most advanced stage, SARS causes failure of the lungs, heart, or liver.
According to the CDC, authorities marked 8,098 people as having contracted SARS. Of these, 774 infections were fatal. This equates to a mortality rate of 9.6%.
Complications were more likely in older adults, and half of all people over 65 years of age who became ill did not survive. Authorities eventually controlled SARS in July 2003.
MERS spread due to the coronavirus known as MERS-CoV. Scientists first recognized this severe respiratory illness in 2012 after it surfaced in Saudi Arabia. Since then, it has spread to other countries.
The virus has reached the U.S., while the largest outbreak outside the Arabian Peninsula occurred in South Korea in 2015.
Symptoms of MERS include fever, breathlessness, and coughing. The illness spreads through close contact with people who already have an infection. However, all cases of MERS have links to individuals recently returning from travel to the Arabian Peninsula.