Researchers culling data from coronavirus patients in the UK and US have identified six distinct “types” of COVID-19 infections that come with particular clusters of symptoms.
The new study, which has not been peer reviewed, found that while continuous cough, fever and loss of smell remain the hallmark symptoms of COVID-19, other associated symptoms such as headaches, chest pains, fatigue, diarrhea, confusion, loss of appetite and shortness of breath can help predict various outcomes.
The researchers at King’s College London say some of the clusters appear to be more closely associated with hospitalization than others, raising the hope that early identification of a patient’s “type” of infection could help those most at risk of life-threatening complications.
Focusing on 1,600 COVID-19 patients in the UK and US who regularly logged their symptoms on an app in March and April, the researchers identified these six clusters.
1. Flu-like with no fever: Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever.
2. Flu-like with fever: Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite.
3. Gastrointestinal: Headache, loss of smell, loss of appetite, diarrhea, sore throat, chest pain, no cough.
4. Severe level one, fatigue: Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue.
5. Severe level two, confusion: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain.
6. 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.
When the team looked at which symptom clusters were more likely to require oxygen treatment or ventilation, they found that only 1.5% of people with cluster 1, 4.4% of people with cluster 2 and 3.3% of people with cluster 3 COVID-19 required breathing support.
These figures were 8.6%, 9.9% and 19.8% for clusters 4, 5 and 6 respectively, the researchers said.
Nearly half of the patients in cluster 6 ended up in the hospital, compared with just 16% of those in cluster 1, they said.
Broadly, people who fell into clusters 4, 5 or 6 tended to be older and frailer, and were more likely to be overweight and have pre-existing conditions such as diabetes or lung disease, they said.
“These findings have important implications for care and monitoring of people who are most vulnerable to severe COVID-19,” Dr. Claire Steves, one of the study leads, said in a press statement.
“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 – simple care that could be given at home, preventing hospitalizations and saving lives,” she said.