COVID-19

  • A study from the University of Southern California was able to determine that COVID-19 symptoms often start in a certain order.
  • According to the study, while influenza typically begins with a cough, the first symptom of COVID-19 is fever.
  • However, physicians working with patients with COVID-19 said that in their experience the symptoms aren’t as predictable.

The symptoms of COVID-19, including fever and cough, are similar to the symptoms in a host of other common diseases, including the seasonal flu.

With flu season in full swing, how can you tell if a fever is a symptom of the flu or COVID-19? A new study has shed light on how COVID-19 symptoms present, which may help people trying to figure out if their cough is just a cough or something worse.

The research from the University of Southern California (USC) was able to determine that COVID-19 symptoms often start in a certain order.

This finding might help people with COVID-19 self-isolate and get treatment sooner, which could significantly improve patient outcomes.

“This order is especially important to know when we have overlapping cycles of illnesses like the flu that coincide with infections of COVID-19,” said Peter Kuhn, PhD, one of the study authors and professor of medicine, biomedical engineering, and aerospace and mechanical engineering at USC. “Doctors can determine what steps to take to care for the patient, and they may prevent the patient’s condition from worsening.”

Scientists used Chinese data

To predict the order of symptoms, researchers analyzed rates of symptom incidence collected by the World Health Organization (WHO) for over 55,000 confirmed COVID-19 cases in China.

They also looked at a data set of almost 1,100 cases collected between December 2019 and January 2020 by the China Medical Treatment Expert Group for COVID-19 and provided by the National Health Commission of China.

To compare the order of COVID-19 symptoms to influenza, the researchers analyzed data from over 2,000 influenza cases in North America, Europe, and the Southern Hemisphere reported to health authorities between 1994 and 1998.

“The order of the symptoms matter,” said Joseph Larsen, lead study author and USC Dornsife doctoral candidate. “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.”

COVID-19 symptoms timeline

According to the study’s findings, this is the order of symptoms that people with COVID-19 can experience:

  1. fever
  2. cough and muscle pain
  3. nausea or vomiting
  4. diarrhea

“The study found that patients with seasonal flu more commonly developed a cough before the onset of fever,” Dr. Robert Glatter, emergency physician at Lenox Hill Hospital in New York, told Healthline. “In reality, this may be difficult to discern since the flu often begins abruptly with a triad of symptoms, including back pain, chills, along with a dry cough.”

Glatter said that the findings are potentially useful “when evaluating multiple patients in a busy clinical setting.”

According to the study, while influenza typically begins with a cough, the first symptom of COVID-19 is fever.

“Our results support the notion that fever should be used to screen for entry into facilities as regions begin to reopen after the outbreak of Spring 2020,” the study authors wrote.