Anju Goel, MD, is board-certified in internal medicine. She has over 10 years of experience in the California public health system addressing communicable disease, health policy, and disaster preparedness.
The novel coronavirus, widely referred to as COVID-19, is a disease that surfaced in Wuhan, China at the end of 2019. The virus that causes COVID-19 is called SARS-CoV-2, and belongs to the family of coronaviruses, several of which cause the common cold.
While COVID-19 is not exclusively a respiratory disease, the most common symptoms are respiratory in nature, including dry cough, congestion, and loss of taste or smell. But other reported symptoms are more systemic, ranging from fever and fatigue to muscle aches and gastrointestinal issues.
COVID-19 is primarily transmitted between people who are in close contact with one another. It spreads via respiratory droplets emitted when someone coughs, sneezes, sings, talks, or breathes. Because of the way COVID-19 spreads, wearing a mask, washing your hands, and practicing social distancing are currently the best methods to prevent infection.
A mild to moderate case of coronavirus will typically last about two weeks. According to the Centers for Disease Control and Prevention (CDC), research shows the virus is no longer capable of infecting cells and replicating after about 10 days following the onset of symptoms. In more severe cases, it might take the virus 10 to 20 days to stop replicating and being infectious. In rare instances, people experience lingering, systemic symptoms months after their bodies have cleared the virus.
COVID-19 can be airborne, although that’s not the primary way the virus spreads. Most infections are caused by heavier respiratory droplets spread between people in close contact when they cough, sneeze, talk, sing, or breathe. However, smaller droplets can linger in the air for minutes or hours, especially in poorly-ventilated and enclosed spaces.
It is possible to get COVID-19 twice, though there are very few documented cases. This is because the SARS-CoV-2 virus mutates over time. In the known cases of reinfection, people were infected with different strains of the virus as a result of those mutations. Mutations are normal and do not usually create more virulent strains of a virus. Experts say a SARS-CoV-2 infection may be protective against later infections, but not completely preventative.
COVID-19 is easily spread between people in close contact who transmit respiratory droplets: particles emitted when we cough, sneeze, talk, sing, and breathe. Airborne transmission is possible when smaller versions of these droplets linger in the air, but it’s less common and more limited to poorly-ventilated spaces. Surface transmission is also possible when surfaces are contaminated with COVID-19, but is not a major driver of infections.
The symptoms of COVID-19 appear two to 14 days after exposure. While there are many symptoms of the disease, the CDC lists the most common as:
Rare symptoms include (but are not limited to) delirium, pink eye, deep vein thrombosis, stroke, and discolored toes. If you have significant trouble breathing, persistent chest pain, new confusion, bluish lips or face, and are having trouble staying awake, seek emergency medical attention.
While it’s uncommon to become infected from surfaces, research from Australia shows that the SARS-CoV-2 virus remains on some non-porous surfaces for up to 28 days. At room temperature (68°F), the virus can live on stainless steel, vinyl, glass, and paper currency for 28 days. On cotton, the virus is undetectable after day 14. At higher temperatures, the SARS-CoV-2 survives for a shorter period of time. At 104°F, the virus becomes undetectable on non-porous surfaces after 48 hours, and on cotton, after 24 hours.
You can have coronavirus without experiencing fever. However, research shows COVID-19 symptoms may appear in a specific order, usually starting with fever. After looking at data from 57,000 patients, researchers think the most common symptom trajectory is fever, cough, nausea/vomiting, and diarrhea.
Results of RT-PCR COVID-19 tests, which are considered to be the most accurate, typically take one to five days. The FDA says it is possible to get same-day results, but a week or more wait time is possible depending on lab capacity.
World Health Organization. Coronavirus disease (COVID-19) Q&A. October 12, 2020.
Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19): How COVID-19 Spreads. October 28, 2020.
Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19). Duration of Isolation and Precautions for Adults with COVID-19. October 19, 2020.
Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19). How COVID-19 Spreads. October 28, 2020.
Food and Drug Administration. Coronavirus Disease 2019 Testing Basics. Updated November 6, 2020.