COVID-19 The Coronavirus Disease 2019

Background on COVID-19

Background on COVID-19

Background on COVID-19

 

CDC is responding to an outbreak of respiratory disease caused by a  novel (new) coronavirus that was first detected in China and which has  now been detected in almost 90 locations internationally, including in  the United States. The virus has been named “SARS-CoV-2” and the disease  it causes has been named “coronavirus disease 2019” (abbreviated  “COVID-19”).


On January 30, 2020, the International Health Regulations Emergency  Committee of the World Health Organization declared the outbreak a “public health emergency of international concernexternal icon”  (PHEIC). 


On January 31, 2020, Health and Human Services Secretary Alex  M. Azar II declared a public health emergency (PHE) for the United  States to aid the nation’s healthcare community in responding to  COVID-19.

The Virus

Background on COVID-19

Background on COVID-19

 

There is much to learn about the novel coronavirus (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). Based on what is currently known about COVID-19, spread from person-to-person of this virus happens most frequently among close contacts (within about 6 feet). This type of transmission occurs via respiratory droplets. On the other hand, transmission of novel coronavirus to persons from surfaces contaminated with the virus has not been documented. Recent studies indicate that people who are infected but do not have symptoms likely also play a role in the spread of COVID-19. Transmission of coronavirus occurs much more commonly through respiratory droplets than through fomites. Current evidence suggests that SARS-CoV-2 may remain viable for hours to days on surfaces made from a variety of materials. Cleaning of visibly dirty surfaces followed by disinfection is a best practice measure for prevention of COVID-19 and other viral respiratory illnesses in households and community settings.

It is unknown how long the air inside a room occupied by someone with confirmed COVID-19 remains potentially infectious. Facilities will need to consider factors such as the size of the room and the ventilation system design (including flowrate [air changes per hour] and location of supply and exhaust vents) when deciding how long to close off rooms or areas used by ill persons before beginning disinfection.  Taking measures to improve ventilation in an area or room where someone was ill or suspected to be ill with COVID-19 will help shorten the time it takes respiratory droplets to be removed from the air.

Illness Severity

Background on COVID-19

Illness Severity

 

The complete clinical picture with regard to COVID-19 is not fully  known. Reported illnesses have ranged from very mild (including some  with no reported symptoms) to severe, including illness resulting in  death. While information so far suggests that most COVID-19 illness is  mild, a reportexternal icon out of China suggests serious illness occurs in 16% of cases. Older  people and people of all ages with severe underlying health conditions —  like heart disease, lung disease and diabetes, for example — seem to be  at higher risk of developing serious COVID-19 illness.

Learn more about the symptoms associated with COVID-19.

There are ongoing investigations to learn more. This is a rapidly  evolving situation and information will be updated as it becomes  available.

Risk Assessment

Risk Assessment

Illness Severity

 

Outbreaks of novel virus infections among people are always of public  health concern. The risk to the general public from these outbreaks  depends on characteristics of the virus, including how well it spreads  between people; the severity of resulting illness; and the medical or  other measures available to control the impact of the virus (for  example, vaccines or medications that can treat the illness). That this  disease has caused severe illness, including illness resulting in death  is concerning, especially since it has also shown sustained  person-to-person spread in several places. These factors meet two of the  criteria of a pandemic. As community spread is detected in more and  more countries, the world moves closer toward meeting the third  criteria, worldwide spread of the new virus.

It is important to note that current circumstances suggest it is  likely that this virus will cause a pandemic. This is a rapidly evolving  situation and CDC’s risk assessment will be updated as needed.

Current risk assessment:

  • For most people, the immediate risk of being exposed to the virus  that causes COVID-19 is thought to be low. This virus is not currently  widespread in the United States.
  • People in places where ongoing community spread of the virus that  causes COVID-19 has been reported are at elevated risk of exposure, with  increase in risk dependent on the location.
  • Healthcare workers caring for patients with COVID-19 are at elevated risk of exposure.
  • Close contacts of persons with COVID-19 also are at elevated risk of exposure.
  • Travelers returning from affected international locations where community spread is occurring also are at elevated risk of exposure, with increase in risk dependent on the location.

CDC has developed guidance to help in the risk assessment and management of people with potential exposures to COVID-19.

What May Happen

Risk Assessment

What May Happen

 

More cases of COVID-19 are likely to be identified in the coming  days, including more cases in the United States. It’s also likely that  sustained person-to-person spread will continue to occur, including  throughout communities in the United States. It’s likely that at some  point, widespread transmission of COVID-19 in the United States will  occur.

Widespread transmission of COVID-19 would translate into large  numbers of people needing medical care at the same time. Schools,  childcare centers, and workplaces, may experience more absenteeism. Mass  gatherings may be sparsely attended or postponed. Public health and  healthcare systems may become overloaded, with elevated rates of  hospitalizations and deaths. Other critical infrastructure, such as law  enforcement, emergency medical services, and sectors of the  transportation industry may also be affected. Healthcare providers and  hospitals may be overwhelmed. At this time, there is no vaccine to  protect against COVID-19 and no medications approved to treat it. Nonpharmaceutical interventions would be the most important response strategy.

Symptoms

Risk Assessment

What May Happen

 

Watch for symptoms

Reported illnesses have ranged from mild symptoms to severe illness and death for confirmed coronavirus disease 2019 (COVID-19) cases.

These symptoms may appear 2-14 days after exposure (based on the incubation period of MERS-CoV viruses).

  • Fever
  • Cough
  • Shortness of breath