What’s to know about coronaviruses?

Coronaviruses are types of viruses that typically affect the respiratory tract of mammals, including humans. They are associated with the common cold, pneumonia, and severe acute respiratory syndrome (SARS) and can also affect the gut.

A coronavirus was first isolated in 1937 from an infectious bronchitis virus in birds that has the ability to seriously devastate poultry stocks.

These viruses are responsible for between 15 and 30 percent of common colds.

Over the last 70 years, scientists have found that coronaviruses can infect mice, rats, dogs, cats, turkeys, horses, pigs, and cattle. Most recently, authorities identified a coronavirus outbreak in China that has now reached other countries.

This MNT Knowledge Center article will focus on the different types of human coronaviruses, their symptoms, how they are transmitted, and two particularly dangerous diseases that can be caused by coronaviruses: SARS and MERS.

Fast facts on coronaviruses

  • There is no cure for the common cold.
  • A coronavirus causes both SARS and MERS.
  • Coronaviruses infect many different species.
  • There are seven known human coronaviruses.
  • SARS spread from China to cause infection in 37 countries, killing 774 people.

What are coronaviruses?

Human coronaviruses (HCoV) were first identified in the 1960s in the noses of patients with the common cold. Two human coronaviruses are responsible for a large proportion of common colds OC43 and 229E.

Coronaviruses were given their name based on the crown-like projections on their surfaces. “Corona” in Latin means “halo” or “crown.”

Among humans, infection most often occurs during the winter months as well as early spring. It is not uncommon for a person to become ill with a cold that is caused by a coronavirus and then catch it again about four months later.

This is because coronavirus antibodies do not last for a very long time. Also, the antibodies for one strain of coronavirus may be useless against other strains.

Symptoms

Cold- or flu-like symptoms usually set in from two to four days after coronavirus infection, and they are typically mild. However, symptoms vary from person to person, and some forms of the virus can be fatal.

Symptoms include:

  • sneezing
  • a runny nose
  • fatigue
  • a cough
  • in rare cases, fever
  • a sore throat
  • exacerbated asthma

Human coronaviruses cannot be cultivated in the laboratory easily, unlike the rhinovirus, another cause of the common cold. This makes it difficult to gauge the coronavirus’ impact on national economies and public health.

There is no cure, so treatments include taking care of yourself and over-the-counter (OTC) medication:

  • Rest and avoid overexertion.
  • Drink enough water.
  • Avoid smoking and smoky areas.
  • Take acetaminophen, ibuprofen or naproxen to reduce pain and fever.
  • Use a clean humidifier or cool mist vaporizer.

The virus responsible can be diagnosed by taking a sample of respiratory fluids, such as mucus from the nose, or blood.