Worldwide spread of the new coronavirus led the World Health Organization (WHO) to designate COVID-19 as a pandemic on March 11, 2020. On March 13, 2020, the President of the United States declared the COVID-19 pandemic a national emergency. The latest situation summary updates are available on the CDC's coronavirus webpage.

There is an ongoing effort to better understand disease transmissibility, infectivity, and severity associated with this pandemic. According to the CDC:

  • Person-to-person spread most likely occurs during close (within 6 feet) contact with an infected person.
  • Person-to-person spread is thought to occur mainly via droplets of respiratory secretions produced when an infected person coughs or sneezes, similar to how influenza and other respiratory diseases spread. These droplets are believed to enter the mouths and noses of people nearby, and can be inhaled into the nose and lungs.
  • COVID-19 can also be transmitted by touching surfaces or objects contaminated with SARS-CoV-2 (the virus that causes the disease), then touching their mouth, nose, or possibly the eyes.

In many areas, the virus that causes COVID-19 is spreading very easily and sustainably between people. This is referred to as community transmission, which means that people in certain areas are being infected with the virus and transmission cannot be traced to a single infected person. Infected people may not be sure how, when, or where they became infected. Exposure may occur in community, home, and workplace settings. As the pandemic evolves, different parts of the United States are experiencing different levels of COVID-19 disease.

Risk factors for worker exposure to SARS-CoV-2 include:

  • Job duties involving close (within 6 feet) contact with infected people or other sources of the virus. This includes close contact with suspected or confirmed COVID-19 patients or their infectious body fluids in the healthcare, postmortem care, and laboratory sectors.
  • In almost all sectors, job duties involving either sustained close contact (within 6 feet) or frequent close contact with coworkers, customers, and/or members of the general public who may be infected with the virus without knowing it. Infected people can spread the virus even if they do not have signs and/or symptoms of COVID-19.
  • Social conditions conducive to transmission, including in areas of high population density or where people have frequent and/or prolonged close contact, either in the community or in the workplace. This includes situations in which workers live in shared housing or gather in groups, especially without maintaining social distancing.

Many workers, even those who do not encounter infectious people in the course of their job duties, can have similar exposure risks as the general American public in a pandemic. Exposure risks can increase for workers interacting with individuals with higher risks of contracting COVID-19 and for workers who have exposure to other sources of the virus in the course of their job duties. OSHA has developed guidance for classifying worker exposure risks into lower (caution), medium, high, and very high risk categories and provides guidance and resources for protecting workers who perform job tasks in each risk level; see the Control and Prevention page of this Safety and Health Topics page.

In addition to this webpage and other OSHA guidance, employers and workers should consult interim CDC guidance specific to COVID-19, including information for businesses. CDC also provides tips on what the general public should do during the ongoing pandemic.