Cough or fever, the order of COVID-19 symptoms changes depending on the variant

The order of symptoms manifested by patients with COVID-19 It is not always the same, but differs depending on the variant, according to a study published in the journal PLOS Computational Biology.

The objective of the study was to determine if the order of the symptoms of COVID-19 changed according to the geographical region or the characteristics of each patient.

To find out, the researchers developed a mathematical model that predicts the order of symptoms based on the initial 2020 outbreak in Wuhan, China, and applied it to a set of 373,883 cases detected in the United States between January and May 2020.

Surprisingly, the order of symptoms had changed between the two countries: in the initial outbreak in China, fever most often preceded coughing, nausea, and vomiting – which were a third symptom – but in the United States, coughing was ranked as the first symptom, followed by fever and diarrhea.

By analyzing additional data from Brazil, Hong Kong, and Japan, the team showed that the differences in the order of symptoms were not related to geographic region, climate, or patient characteristics, but rather to SARS-CoV-2 variants. .

The presence of the D614G variant in one area, which was predominant in the United States in early 2020, was associated with an increased likelihood of cough as the first symptom of COVID-19 manifested by patients.

As Japan moved from the original Wuhan reference strain to the D614G variant, the order of symptoms changed as well.

“These findings indicate that the order of symptoms may change with the mutation in the viral disease and raise the possibility that the D614G variant is more transmissible because infected people are more likely to cough in public before becoming incapacitated with a fever.” the authors conclude.