What to know about coronaviruses

 Coronaviruses cause a range of illnesses, including COVID-19. They typically affect the respiratory tract, but their effects can extend well beyond the respiratory system.

At the end of 2019, scientists identified a coronavirus outbreak in China. Experts named the newly identified virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the illness that it causes coronavirus disease 19 (COVID-19).

There are many types of coronavirus. Some causeTrusted Source mild illnesses, such as the common cold. Others can cause severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), which can be life threatening.

Many coronaviruses are present in animals but do not affect humans. Sometimes, however, a virus mutates in a way that allows it to infect humans. Scientists call these human coronaviruses, or “HCoVs.”

This article looks at a few coronaviruses that can infect humans, the illnesses they cause, and how they transmit. Specifically, we focus on three dangerous diseases caused by coronaviruses: COVID-19, SARS, and MERS.

What is a coronavirus?

Researchers first identified a coronavirus in 1937. They isolated one that was responsible for a type of bronchitis in birds and had the potential to devastate poultry stocks.

Scientists found evidence of human coronaviruses in the 1960sTrusted Source, in the noses of people with the common cold. SeveralTrusted Source human coronaviruses cause mild illnesses, including colds.

The name “coronavirus” refers to the crown-like projections on the pathogen’s surface. “Corona” in Latin means “halo” or “crown.”

In humans, coronavirus infections most often occur in the winter and early spring, but they can happen at any time.

COVID-19

Late in 2019, scientists started monitoring the outbreak of a new coronavirus, SARS-CoV-2, which causes COVID-19. They first identified the virus in Wuhan, China.

The virus spread rapidly around the world, and the World Health Organization (WHO) declared a pandemic in March 2020Trusted Source.

The new coronavirus has been responsible for millions of infections globally, and it has caused more than 2 million deaths. The mortality rate varies from country to country. In the United States, it is around 1.7%.

Many researchersTrusted Source believe SARS-CoV-2 first infected bats before spreading to other animals, including humans. Some of the first people with COVID-19 had links to a live animal and seafood market. Overall, however, there is little conclusive information about the origins of the virus. Scientists are still investigating its source and initial pattern of spreading.

Many people with COVID-19 experience a relatively mild form of the disease that does not require specialist treatment. Others develop severe breathing problems and need to spend time in the hospital. In some cases, it is fatal.

Some people who do not have severe symptoms initially go on to develop health issues that continue for weeks or months, according to the Centers for Disease Control and Prevention (CDC)Trusted Source.

People with a higher risk of severe COVID-19 symptoms includeTrusted Source older adults and those with underlying medical conditions, including high blood pressure, heart and lung problems, diabetes, and cancer.

According to the CDCTrusted Source, most children with COVID-19 have mild or no symptoms. Fewer children have developed COVID-19 than adults. That said, infants and children with certain medical conditions may have an increased risk of severe illness and death.

There may also be a higher riskTrusted Source of severe COVID-19 during pregnancy, as well as an increased risk of issues such as preterm birth. However, the role of the virus in these circumstances remains unclear.

Symptoms of COVID-19

People may start to experience COVID-19 symptoms 2–14 daysTrusted Source after exposure to SARS-CoV-2.

Symptoms of COVID-19 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

Tests can detect the infection, even if there are no symptoms.

As the virus progresses, severe complications can arise. COVID-19 can affectTrusted Source a wide range of body systems and lead to multiple organ failure.

Source: Medical News Today