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About COVID-19

The Illinois Department of Public Health, local health departments, and public health partners throughout Illinois, and federal agencies, including the Centers for Disease Control and Prevention (CDC), began responding to an outbreak of respiratory illness caused by a novel coronavirus called COVID-19 that was first identified in December 2019 during an outbreak in Wuhan, China. COVID-19 has spread throughout the world, including the United States, since it was detected and was declared a public health emergency for the U.S. on January 31, 2020 to aid the nation’s health care community in responding to the threat.  The World Health Organization announced March 11, 2020 that the spread of coronavirus qualifies as a global pandemic.

In addition, Gov. JB Pritzker issued a disaster proclamation March 9, 2020 regarding COVID-19 that gives the state access to federal and state resources to combat the spread of this newly emerged virus.

The first case of COVID-19 in the United States was reported January 21, 2020 and the first confirmed case in Illinois was announced January 24, 2020 (a Chicago resident). The first cases outside Chicago and Cook County were reported March 11, 2020 in Kane and McHenry counties. The current count of cases of COVID-19 in the United States is available on the CDC webpage at Illinois case totals and test results are listed here.

Coronaviruses are a large family of viruses, some causing illness in people, and others that circulate among animals, including camels, cats, and bats.  Rarely animal coronaviruses can evolve and infect people and then spread between people.

Human coronaviruses are common throughout the world and commonly cause mild to moderate illness in people worldwide. However, the emergence of novel (new) coronaviruses, such as SARS and MERS, have been associated with more severe respiratory illness.


People with COVID-19 have had a wide range of symptoms reported - ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus.  People with COVID-19 may have these symptoms:

  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea

When to seek emergency medical attention

If someone is showing any of these signs, seek medical care immediately:

  • Trouble breathing
  • Persistent pain or pressure in the chest
  • New confusion
  • Inability to wake or stay awake
  • Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

This list is not all possible symptoms. Please call your medical provider for any other symptoms that are severe or concerning to you.


COVID-19 spreads when an infected person breathes out droplets and very small particles that contain the virus. These droplets and particles can be breathed in by other people or land on their eyes, noses, or mouth. In some circumstances, they may contaminate surfaces they touch.

Factors that lower or increase risk of transmission include:

  • Length of time you were with the infected person
  • If the infected person was coughing, singing, shouting, or breathing heavily
  • If the infected person had symptoms at the time of the exposure
  • If you or the infected person was wearing a mask during the exposure
  • How well the space was ventilated, and the air filtered
  • How close you were to the infected person


The following can help prevent the spread of coronaviruses and protect you, your household, and your community from severe illness from COVID-19:

  • Stay up-to-date with COVID-19 vaccination
  • Improve ventilation in your home
  • Wear a mask - cover your mouth and nose with a mask when in indoor and crowded outdoor public settings when Community Transmission Levels are high
  • Stay home if you are sick
  • Get tested for COVID-19 if needed
  • Talk to your provider about treatment if you have COVID-19 and are at high risk of getting very sick
  • If exposed to someone with COVID-19, wear a mask for 10 days and get tested
  • Wash your hands often with soap and water for at least 20 seconds especially after you have been in a public place, or after blowing your nose, coughing, or sneezing

If you test positive for COVID-19, take the following steps to care for yourself and protect other people in your home and community:

  • Contract your provider to discus treatment options if you are at high risk for severe disease
  • Stay home for at least 5 days
  • Separate yourself from other people and inform your close contacts
  • Monitor your symptoms and keep in touch with your medical provider, especially if your symptoms worsen
  • Call ahead before visiting your provider
  • Wear a well-fitting mask if you must be around others and pets, even in your home
  • Cover your coughs and sneezes
  • Clean your hands often
  • Avoid sharing personal household items
  • Clean surfaces in your home regularly
  • Take steps to improve ventilation in your home

For additional information, visit CDC’s What to Do If You Are Sick page.