Covid-19 symptoms: Does fever come first or cough?

A new research claims to have found the likely order in which covid-19 symptoms begin to appear. This advancement can help clinicians rule out other diseases, and help patients seek proper care promptly and go into self-isolation sooner.

Published in the journal Frontiers in Public Health, the study suggests that the likely order of symptoms in covid-19 patients is fever, followed by cough, muscle pain, and then nausea and/or vomiting, and diarrhoea.

Co-author of the study and a professor of medicine and biomedical engineering at the University of Southern California (USC) in the US, Peter Kuhn explains that, "This order is especially important to know when we have overlapping cycles of illnesses like the flu that coincide with infections of covid-19."

Kuhn believes that with this new information doctors can determine the steps to be taken for taking care of the patients and prevent their conditions from worsening.

According to the researchers if the patients can be identified earlier, it may reduce the hospitalisation time since better approaches to treatments for covid-19 have emerged from what we had when the pandemic first began.

The scientists have predicted the order of symptoms from data of more than 55,000 confirmed coronavirus cases in China on the rates of symptom incidence. All of these data were collected within February 16 to 24 by the World Health Organization (WHO).

A dataset of nearly 1,100 cases collected from December 11, 2019 through January 29, 2020, by the China Medical Treatment Expert Group via the National Health Commission of China, was also studied for this research.

The scientists examined influenza data for comparison. They derived that from 2,470 cases in North America, Europe and the Southern Hemisphere, which were reported to health authorities from 1994 to 1998.

"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," said the lead author from USC, Joseph Larsen.

Fever and cough happen to be very frequently associated with a variety of respiratory illnesses. However, it is the timing and symptoms in the upper and lower gastrointestinal tract that set covid-19 apart.

"The first two symptoms of covid-19, SARS, and MERS are fever and cough. However, the upper GI tract (nausea/vomiting) seems to be affected before the lower GI tract (diarrhoea) in covid-19, which is the opposite from MERS and SARS," the scientists wrote in the study.

The research claims that not many of the patients experienced diarrhoea as an initial symptom.

"This report suggests that diarrhoea as an early symptom indicates a more aggressive disease, because each patient in this dataset that initially experienced diarrhoea had pneumonia or respiratory failure eventually," they added.

"The highest reported symptom is fever, followed by cough or dyspnoea, and then finally, a small percent of patients reported diarrhoea. This order confirms the most likely paths that we have determined."