Coronaviruses are a large group of viruses that cause diseases in animals and humans. They often circulate among camels, cats, and bats, and can sometimes evolve and infect people.
In animals, coronaviruses can cause diarrhea in cows and pigs, and upper respiratory disease in chickens. In humans, the viruses can cause mild respiratory infections, like the common cold, but can lead to serious illnesses, like pneumonia.
Coronaviruses are named for the crown-like spikes on their surface. Human coronaviruses were first identified in the mid-1960s. They are closely monitored by public health officials.
Novel Coronavirus (COVID-19)
A novel coronavirus (COVID-19, previously referred to as 2019-nCoV) emerged in a seafood and poultry market in the Chinese city of Wuhan in 2019. Cases have been detected in most countries worldwide, and on March 11, 2020, the World Health Organization characterized the outbreak as a pandemic. Human-to-human transmission occurs through close contact.
Middle East Respiratory Syndrome (MERS)
Middle East Respiratory Syndrome (MERS) was first reported in 2012 in Saudi Arabia and spread to more than 25 other countries. MERS originated in camels and emerged to infect people. Symptoms usually include fever, cough, and shortness of breath, and often progress to pneumonia. About 3 or 4 out of every 10 patients reported with MERS have died. MERS cases continue to occur, primarily in the Arabian Peninsula; however, as of 2019, there have been only two confirmed cases of MERS in the US, both in 2014.
Severe Acute Respiratory Syndrome (SARS)
Severe Acute Respiratory Syndrome (SARS) originated in small mammal and emerged to infect people. SARS was first reported in Southern China in 2002 and the illness spread to more than two dozen countries in North America, South America, Europe, and Asia. Symptoms include fever, chills, and body aches, and may progress to pneumonia. Infection with the SARS virus causes acute respiratory distress (severe breathing difficulty), with a mortality rate of about 10 percent. No human cases of SARS have been reported anywhere in the world since 2004.
Most people get infected with human strains of coronaviruses at some point in their lives. These illnesses usually last for a short amount of time, and symptoms may include:
- runny nose
- sore throat
Human coronaviruses can cause other illnesses, such as pneumonia or bronchitis. This is more common in individuals with heart and lung disease, those with weakened immune systems, infants, and older adults.
There are laboratory tests to detect human coronaviruses. Laboratory testing is more likely to be used for patients who have severe disease. If you think you may have a coronavirus, talk to a healthcare professional about any recent travel or contact with animals.
Human coronaviruses can spread through:
- coughing and sneezing
- close personal contact, such as touching or shaking hands
- touching an object or surface with the virus on it, then touching your mouth, nose, or eyes
- rarely, fecal contamination
There are currently no vaccines available to protect against human coronaviruses, but there are steps you can take to help prevent infection:
- wash your hands often with soap and water for at least 20 seconds
- avoid touching your eyes, nose, or mouth
- cover your mouth and nose when you cough or sneeze
- clean and disinfect objects and surfaces
- avoid close contact with people who are sick and stay home while you are sick
There is currently no specific treatment, other than good supportive care:
- take pain and fever medications
- use a humidifier or take a hot shower
- drink plenty of liquids
- stay home and rest
If you are concerned about symptoms, call a healthcare professional and tell them about recent overseas travel. Do not go directly to the doctor’s office or hospital, where you may infect other people.
Updated March 19, 2020
The National Foundation for Infectious Diseases and the Alliance for Aging Research developed this resource on COVID-19 for older adults and people with underlying health conditions.
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