Typically, coronaviruses affect birds and mammals’ respiratory tracts, including humans. Physicians identify them with the common cold, bronchitis, pneumonia, severe acute respiratory syndrome (SARS), and coronavirus disease 2019 (COVID-19) (COVID-19). The gut may also be infected by these viruses.
The common cold is typically caused by coronaviruses, but they may be responsible for more severe diseases.
Over the past 80 years, scientists have found that mice, rats, dogs, cats, turkeys, horses, pigs, and cattle may be infected by these viruses. These animals also transfer viruses to humans.
Most recently, authorities detected a coronavirus outbreak in China at the end of 2019 that went on to hit other nations. The virus is called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it causes the illness COVID-19.
We explain the various forms of human coronavirus in this article, the symptoms of the health problems they cause, and how they are transmitted from person to person.
We concentrate on 3 particularly deadly diseases caused by coronaviruses: COVID-19, SARS, and Middle East respiratory syndrome (MERS) (MERS).
What is a coronavirus?
In 1937, researchers first identified a coronavirus, isolating one that was responsible for a form of bronchitis in birds that could devastate stocks of poultry.
In the 1960s, in the noses of people with the common cold, scientists discovered signs of human coronaviruses.
Human coronaviruses include 229E, NL63, OC43, and HKU1, which are especially prevalent.
The word “coronavirus” originates from the crown-like projections on the surfaces of the virus. “Corona” means “halo” in Latin or “crown.”
In humans, in the winter and early spring, coronavirus infections most frequently occur.
COVID-19
The Centers for Disease Control and Prevention (CDC) began tracking the outbreak of SARS-CoV-2, a new coronavirus that causes COVID-19, in 2019. They first detected the virus in Wuhan, China.
The virus has spread to almost every nation since then, prompting the World Health Organization (WHO) to announce a pandemic.
Tens of millions of infections worldwide have been caused by the current coronavirus, causing over a million deaths. Of these infections and deaths, the United States has seen the largest number.
The first individuals with COVID-19 had links to a market for live animals and seafood. This indicates that the virus was originally transmitted to humans by animals. Then, individuals with no links to the market developed the disease, verifying that the virus can pass from person to person.
The majority of individuals who experience COVID-19 have a relatively mild type of the illness. Around 80 percent of people who get COVID-19 recover without having to be admitted to a hospital, according to the WHO.
The remaining 20% get seriously ill and have trouble breathing.
Some individuals, including older adults and people with chronic medical conditions, including high blood pressure, heart and lung disorders, diabetes and cancer, have a greater risk of serious disease and death.
The rate of mortality differs from country to country. The death rate is around 2.8 percent in the U.S. .
Most kids with COVID-19 have slight symptoms or none at all according to the CDC. Fewer children have developed COVID-19 than adults. That said, there may be an increased risk of serious illness and death from COVID-19 among infants and children with certain medical conditions.
Also the current evidence indicates that pregnant women may have a higher risk of severe illness from COVID-19. Although it is unknown if this is due to the virus itself, they may also have an increased risk of issues such as preterm birth.
Symptoms of COVID-19
Individuals can begin to experience COVID-19 symptoms 2–14 days after SARS-CoV-2 exposure, according to the CDC. Symptoms may include:
- a fever
- chills
- a cough
- shortness of breath or difficulty breathing
- a sore throat
- congestion or a runny nose
- fatigue
- a headache
- muscle pain
- a new loss of taste or smell
- nausea, vomiting, or both
- diarrhea
There is currently no vaccine available for COVID-19, although there are many in progress. Even if a person is not having symptoms, tests will detect the infection early on.
According to the CDC, the following groups have a greater chance of developing extreme COVID-19 disease:
- older adults
- people of any age with underlying health conditions, including heart disease, stroke, diabetes, cancer, high blood pressure, and obesity
- pregnant people
Systemic healthcare disparities have placed many people from marginalized racial and ethnic groups at a higher risk of COVID-19 sickness and death.
General symptoms of coronavirus infections
Coronaviruses appear to cause symptoms that are cold or flu-like. The symptoms are usually mild, but they differ from person to person.
Symptoms of coronavirus infections may include:
- a runny nose
- a headache
- a cough
- a fever
- a sore throat
- generally feeling unwell
If it results from a coronavirus infection, there is actually no cure for the common cold. Treatments include self-care and over-the-counter medications.
Taking the following steps may help:
- resting and avoiding overexertion
- drinking plenty of water
- avoiding smoking and smoky areas
- taking acetaminophen (Tylenol) to reduce any pain and a fever
- using a clean humidifier or cool mist vaporizer
In a sample of fluid from the body of an individual, such as a sample of blood or mucus from the nose, the virus responsible for infection may also be detected by a doctor.
Types
In the Coronaviridae family, coronaviruses belong to the subfamily Coronavirinae.
Various forms of coronavirus cause diseases of varying severity. Others spread more easily than others as well.
Seven kinds of coronavirus which can infect humans are currently recognized by physicians. Four common types are:
- 229E (alpha coronavirus) (alpha coronavirus)
- NL63 (alpha coronavirus) (alpha coronavirus)
- OC43 (beta coronavirus) (beta coronavirus)
- HKU1 (beta coronavirus) (beta coronavirus)
MERS-CoV, which causes the disease MERS, and SARS-CoV, the virus responsible for SARS, are rarer strains that cause more serious diseases.
A new strain, named SARS-CoV-2, began circulating and causing the disease COVID-19 in 2019.
Transmission
In public places where physical distance is difficult to maintain, the CDC suggests that individuals wear fabric face masks. This would help delay the spread of the virus through persons, particularly those who are asymptomatic, who do not know that they have contracted it. When continuing to practice physical distancing, individuals should wear cloth face masks. Instructions are available here for making masks at home. Note: It is important that surgical masks are reserved for healthcare staff and N95 respirators.
Researchers assume that viruses, such as mucus, are transmitted through fluids in the respiratory system.
For instance, a coronavirus can spread when a person:
- coughs or sneezes without covering their mouth, dispersing droplets into the air
- has physical contact with someone who has the infection
- touches a surface that contains the virus, then touches their nose, eyes, or mouth
It is still uncertain if human coronaviruses may spread in the same way, although some animal coronaviruses can spread to humans through contact with feces.
At some stage, coronaviruses infect most individuals.
People with symptoms should remain at home, relax, and avoid coming into close contact with others in order to prevent transmission.
Covering the mouth and nose when coughing or sneezing with a tissue or handkerchief can also help avoid transmission. Disposing of used tissues right away and maintaining high levels of hygiene, particularly around the home is important.
SARS
SARS is an infectious disease that is caused by the SARS-CoV coronavirus infection. It leads to a life-threatening type of pneumonia in many cases.
In February 2003, the first mentions of SARS came from Asia. Then the virus spread to over two dozen nations.
Experts don’t consider SARS a risk anymore. The last confirmed human cases of SARS were reported in a laboratory-related outbreak in China in 2004.
Both the upper and lower respiratory tract are affected by SARS-CoV.
SARS symptoms progress over a period of 1 week and begin with a fever. People experience flu-like symptoms early on, like:
- a dry cough
- chills
- diarrhea
- breathlessness
- aches
Usually, pneumonia, a serious lung infection, occurs. SARS causes failure of the lungs, heart, or liver at its most advanced level.
The CDC estimates that during the epidemic, 8,098 people contracted SARS. 774 of them died of the illness. SARS was finally regulated by the authorities in July 2003.
Among older adults, complications were more prevalent. Over half of those who died from the disease were over the age of 65, according to one source.
MERS
MERS is caused by the coronavirus MERS-CoV. After reports arose in Saudi Arabia, scientists first identified this extreme respiratory disorder in 2012. It has spread to other countries since then.
The virus reached the U.S. in 2014. Two individuals in the country tested positive for MERS-CoV. The CDC reports that there is a very low risk of developing MERS within the region.
Symptoms of MERS include:
- a fever
- breathlessness
- coughing
Through close contact with individuals that have the infection, the disease spreads.
A 2019 research into MERS discovered that the disease is fatal in 35.2% of people who develop it.
