Tracker App Reveals Six Types of COVID-19 Infection

A new study of data from a COVID-19 symptom-tracking app finds there are six distinct types of the disease, each with its own cluster of symptoms.

Researchers at King’s College London (KCL; United Kingdom), Lund University (Sweden), Massachusetts General Hospital (MGH; Boston, USA), and other institutions conducted a study that examined time series clustering of symptom presentation that was performed on data derived from a training dataset of completed cases, as collected from the COVID Symptom Study Smartphone application, developed by Zoe Global.

The study, which was published on June 12, 2020, in medRxiv, identified six types of COVID-19:

• 'Flu-like' with no fever: Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever.

• 'Flu-like' with fever: Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite.

• Gastrointestinal: Headache, loss of smell, loss of appetite, diarrhea, sore throat, chest pain, no cough.

• Severe level one, fatigue: Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue.

• Severe level two, confusion: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain.

• Severe level three, abdominal and respiratory: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain, shortness of breath, diarrhea, abdominal pain.

“Patients with level four, five, and six types were more likely to be admitted to hospital and more likely to need respiratory support,” concluded co-lead author Claire Steves, MD, of KCL, and colleagues. “If you can predict who these people are at day five, you have time to give them support and early interventions such as monitoring blood oxygen and sugar levels, and ensuring they are properly hydrated.”

Besides cough, fever, and loss of smell, often highlighted as three key symptoms of COVID-19, app data showed others symptoms, including headaches, muscle pains, fatigue, diarrhea, confusion, loss of appetite, and shortness of breath.