CHEARS

COVID-19 has always been tricky to identify because the symptoms easily overlap with the common cold, flu, and even allergies. Even more confusing? Some people experience no symptoms at all.

To better understand how COVID-19 manifests and progresses, a team of researchers at the University of Southern California attempted to figure out the most common order in which symptoms appear.

Their study, which was recently published in the journal Frontiers in Public Health, analyzed the rates of COVID-19 symptom incidences. They used data collected from the World Health Organization of more than 55,000 novel coronavirus cases in China, as well as a dataset of nearly 1,100 cases collected by the National Health Commission of China.

Based on their findings, the researchers determined that this is the most likely order that someone will experience COVID-19 symptoms:

Fever
Cough
Nausea and/or vomiting
Diarrhea
When they expanded their analysis to include additional symptoms, the order still looked similar:

Fever
Cough
Sore throat, muscle pain, or headache
Nausea and/or vomiting
Diarrhea
The researchers also compared the likely progression of COVID-19 symptoms against the flu and found that the flu was more likely to start with a cough instead of a fever. People with the flu were also more likely to have body aches, headache, and a sore throat before developing a fever, they discovered.

In turn, these results “support the notion” that fever should be used to screen people for COVID-19 before they’re allowed into buildings. “Additionally, our findings suggest that good clinical practice should involve recording the order of symptom occurrence in COVID-19 and other diseases,” the authors wrote.