There has not been a great deal of research on how a human coronavirus spreads from one person to the next.

However, it is believed that the viruses transmit using secreted fluid from the respiratory system.

Coronaviruses can spread in the following ways:

Coughing and sneezing without covering the mouth can disperse droplets into the air, spreading the virus.
Touching or shaking hands with a person that has the virus can pass the virus from one person to another.
Making contact with a surface or object that has the virus and then touching your nose, eyes, or mouth.
On rare occasions, a coronavirus may spread through contact with feces.

People in the U.S. are more likely to contract the disease in the winter or fall. The disease is still active during the rest of the year. Young people are most likely to contract a coronavirus, and people can contract more than one infection over the course of a lifetime. Most people will become infected with at least one coronavirus in their life.

It is said that the mutating abilities of the coronavirus are what make it so contagious.

To prevent transmission, be sure to stay at home and rest while experiencing symptoms and avoid close contact with other people. Covering the mouth and nose with a tissue or handkerchief while coughing or sneezing can also help prevent the spread of a coronavirus. Be sure to dispose of any used tissues and maintain hygiene around the home.
2019-nCov

In 2019, the Centers for Disease Control and Prevention (CDC) started monitoring the outbreak of a new coronavirus. Authorities first identified the virus in Wuhan, China. They have named it 2019 Novel Coronavirus (2019-nCov).

More than 1,000 people have contracted the virus in China. Health authorities have identified several other people with 2019-nCov around the world, including five individuals 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 2019-nCov.

Some of the first people with 2019-nCov had links to an animal and seafood market. This initially suggested that animals transmit the virus to humans. However, people with a more recent diagnosis had no connections with or exposure to the market, suggesting 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.

However, while some viruses are highly contagious, it is less clear with coronaviruses as to how rapidly they will spread.

Symptoms vary from person to person with a 2019-nCov infection. 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. As of January 31, 2020, the virus carries a death rate of 10%, according to a study of 99 people with 2019-nCov.

No vaccine is currently available for 2019-nCov. However, scientists in China and now Australia have replicated the virus. This could allow for early detection and treatment in people who have the virus but are not yet showing symptoms.

soure medicalnewstoday.com