Scientists have now discovered what is the most likely order in which coronavirus symptoms first appear.

According to the study, published in the journal Frontiers in Public Health, the earliest signs of COVID-19 are fever and then cough and muscle pain.

The infected individuals will then likely experience nausea or vomiting and diarrhea.

The researchers noted that an improved understanding of the order of COVID-19’s symptoms would help ill patients decide whether to seek care promptly or self-isolate.

“This order is especially important to know when we have overlapping cycles of illnesses like the flu that coincide with infections of COVID-19,” the study’s co-author Peter Kuhn, professor of medicine, biomedical engineering, and aerospace and mechanical engineering at the USC Dornsife College of Letters, Arts and Sciences, said in a news release.

“Doctors can determine what steps to take to care for the patient, and they may prevent the patient’s condition from worsening.”

The study’s findings could assist doctors in putting together appropriate treatment plans.

Fever and cough are frequently associated with a variety of respiratory illnesses, including Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS).

However, what sets the novel coronavirus apart is the timing and certain symptoms in the upper and lower gastrointestinal tract.

“The upper GI tract (i.e., nausea/vomiting) seems to be affected before the lower GI tract (i.e., diarrhea) in COVID-19, which is the opposite from MERS and SARS,” the scientists wrote in the study.

“Given that there are now better approaches to treatments for COVID-19, identifying patients earlier could reduce hospitalization time,” Joseph Larsen, the study’s lead author and USC Dornsife professor, said in a news release.

“The order of the symptoms matter. Knowing that each illness progresses differently means that doctors can identify sooner whether someone likely has COVID-19, or another illness, which can help them make better treatment decisions.”

The researchers examined data collected by the World Health Organization between February 16 and 24 from more than 55,000 confirmed coronavirus cases in China.

They also studied a dataset of nearly 1,100 cases collected from December 11 to January 29 by the China Medical Treatment Expert Group via the National Health Commission of China.

To compare the order of COVID-19 symptoms to influenza, the researchers analyzed data from roughly 2,500 cases in North America, Europe and the Southern Hemisphere.

There are now more than 21.7 million confirmed cases of coronavirus worldwide, including at least 776,000 deaths, according to the latest data from Johns Hopkins University.

Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV. Follow or contact him on LinkedIn.

Image: Reuters.