CORONAVIRUS UPDATE: As experts learn more about the novel coronavirus, news and information changes. For the latest on the COVID-19 pandemic, please visit the Centers for Disease Control and Prevention.

In December 2019, an outbreak of a deadly mystery respiratory disease (which would come to be known as COVID-19) spread rapidly throughout Wuhan, China, before crossing borders and being named a pandemic by the World Health Organization. But if you can remember back to February 2003, SARS (severe acute respiratory syndrome) became the first pandemic of the 21st century.

Just over 17 years ago, SARS was reported in Asia and a global outbreak infected a total of 8,098 people worldwide. Of these, 774 died, according to WHO. Later, it was found that SARS was caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). Sound familiar? While there are similarities, these two respiratory illnesses are quite distinct. Learn the differences between COVID-19 and SARS and the best practices to prevent infection.

What causes SARS and COVID-19?

Both SARS and COVID-19 are respiratory illnesses that are caused by a specific human coronavirus. But the important fact to note here is that they are caused by different specific coronaviruses. COVID-19 is caused by a novel coronavirus called SARS-CoV-2, according to the Centers of Disease Prevention. SARS is caused by a coronavirus called SARS-associated coronavirus, or SARS-CoV. So what’s a coronavirus?

“Coronaviruses are a large family of viruses that are defined by the lipid envelope that surrounds them,” says Andrew Pavia, MD, the chief of division of pediatric infectious diseases at the University of Utah. “This casing of fats protects the virus—and that’s how they survive on surfaces for a variable length of time.”

What are the symptoms of SARS and COVID-19?

SARS can be difficult to recognize because it mimics other respiratory diseases, such as influenza, according to John Hopkins Medicine. Symptoms of SARS are flu-like, beginning with a fever higher than 100.4° F (38° C). SARS symptoms progress to include:

Headache
Overall feeling of discomfort
Body aches and chills
Sore throat
Cough
Pneumonia
Difficulty breathing
Shortness of breath
Hypoxia (insufficient oxygen in the blood)
Diarrhea (for 10% to 20% of patients)

There is currently no test to diagnose SARS.

As for the symptoms of COVID-19, they are similar—but people can also carry the disease while asymptomatic. Meaning, people who don’t feel sick could still spread the disease and those infected can carry the virus for two days or even up to two weeks before symptoms present. The CDC lists the following symptoms of COVID:

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

Summary: Differences between SARs and COVID-19
	SARS	COVID-19
Virus	Coronavirus	Coronavirus
Symptoms	Fever Head and body aches Cough Shortness of breath Diarrhea Sore throat	Fever Head and body aches Cough Shortness of breath Diarrhea Fatigue, Loss of taste or smell Nausea
Fatality rate	10%	Evolving; see latest stats here
Treatment	OTC meds	OTC meds
Most at risk	Adults over 60 and people with health conditions	Older adults, people who are immunocompromised or have health conditions

How serious are these illnesses?

Both SARS and COVID-19 are contagious and sometimes fatal respiratory illnesses. The death rate for SARS is 10%. According to Mayo Clinic, people older than 60—especially those with underlying conditions such as diabetes or hepatitis—are at the highest risk of serious complications.

As COVID-19 is new and still being studied, there is not a definitive death rate and it seems to differ by country. The Johns Hopkins COVID-19 tracker counts the latest confirmed cases and deaths. Those most seriously affected are:

Older adults
People who are immunocompromised
People with other health conditions like heart disease, lung disease, or diabetes

What are the treatments for these illnesses?

According to the latest research, there is no specific antiviral treatment recommended for COVID-19, and no vaccine is currently available. Treatment for those who are diagnosed is medications for symptom relief, such as ibuprofen and cough suppressants. Oxygen therapy is the main treatment intervention for patients with severe infection. Mechanical ventilation may be necessary in cases of respiratory failure refractory to oxygen therapy, whereas hemodynamic support is essential for managing septic shock.

Similarly, there is currently no treatment to cure SARS. The CDC recommends that patients with SARS receive the same treatment that would be used for a patient with any serious community-acquired atypical pneumonia. SARS-CoV is being tested against various antiviral drugs to see if an effective treatment can be found. Additionally, there has been research for a SARS vaccine, but no vaccine has proven effective or is available.

How do SARS and COVID-19 spread?

SARS-CoV and SARS-CoV-2 spread by close person-to-person contact and are thought to be transmitted most readily by respiratory droplets (droplet spread) produced when an infected person coughs or sneezes. According to the CDC, droplet spread can happen when droplets from the cough or sneeze of an infected person are propelled a short distance (generally up to 3 feet) through the air and deposited on the mucous membranes of the mouth, nose, or eyes of persons who are nearby. The virus also can spread when a person touches a surface or object contaminated with infectious droplets and then touches his or her mouth, nose, or eyes.

How can you prevent these illnesses?

While it is recommended to avoid all unnecessary travel and contact with others during a pandemic, practicing good hygiene is the number one way to prevent contracting illnesses in both times of pandemic and all other times. Therefore, we cannot emphasize enough how important it is to wash your hands to prevent both SARS and COVID-19.

“Cleaning products and good hygiene are very effective and should be the front line,” Dr. Pavia says. “Soap removes superficial contamination and breaks down the fatty envelope that protects coronaviruses—just like it does with grease on our dishes—and removes any contamination from our skin. Soap removes the virus and the mucous associated with the virus from your skin and if it’s not on your skin, it’s not going to get inside of you.”

Dr. Pavia recommends singing “Happy Birthday” in your head twice while washing your hands carefully with soap (he says any kind—whether it’s natural, dish soap, bar soap, or liquid antibacterial soap works) and warm water. Additionally, it’s important to keep the surfaces that you come into contact with often clean as well. “I recommend regularly cleaning bannisters, door knobs, faucets, computer keyboards, phones, and other daily items clean—either by washing them with soap and water or wiping them down with Clorox wipes or something similar. When was the last time most people cleaned their phones? You don’t need to wash these things every hour compulsively, but it’s reasonable—and smart—to give your phone a quick wipe once or twice a day.”

Additionally, health professionals are recommending that you try and keep your face touching to an absolute minimum, as this is how these viruses are most often transported from contaminated surfaces to our membranes (aka mouths, noses, eyes).

Other ways to prevent the spread of COVID-19 and the very-similar disease, SARS, is to always “catch” your coughs and sneezes in the crook of your elbow, stay at home when possible, and avoid large crowds. And when you are in public, wear a mask or face covering.