There are six distinct types of the novel coronavirus, each with a particular cluster of symptoms, concluded UK-based scientists in a new study on COVID-19 published Friday.
Researchers analyzed data collected by the COVID Symptom Study, a voluntary app used by 4 million people in the UK that allows people to log their symptoms of coronavirus. The data revealed people infected with COVID-19 reported additional symptoms on top of the previously recognized cough, fever, and loss of smell.
These symptoms can be grouped into six distinct clusters, according to a statement published by the COVID Symptom Study after researchers on the project from technology company Zoe Global Limited and King’s College London analyzed the results.
Here are the six clusters, or types of COVID-19 listed:
1. Flu-like with no fever
Additional symptoms: Headache, muscle pains, loss of smell, sore throat, cough, chest pain, no fever.
2. Flu-like with fever
Headache, loss of smell, sore throat, cough, hoarseness, loss of appetite, fever.
Headache, loss of smell, loss of appetite, sore throat, chest pain, no cough, diarrhea.
4. Severe level one, fatigue
Headache, loss of smell, cough, chest pain, fever, hoarseness, fatigue.
5. Severe level two, confusion
Headache, loss of smell, loss of appetite, cough, sore throat, chest pain, fever, hoarseness, fatigue, muscle pain, confusion.
6. Severe level three, abdominal and respiratory
Headache, loss of smell, loss of appetite, cough, sore throat, chest pain, fever, hoarseness, fatigue, muscle pain, confusion, diarrhea, shortness of breath, abdominal pain.
COVID-19 flu symptoms unlikely to require hospitalization
The researchers found that some of the ‘types’ of COVID-19 were more prevalent than others, and that certain types more strongly correlated with hospitalization of the patient.
Broadly, COVID-19 patients whose symptoms were mainly flu-like or gastrointestinal were less likely to require hospitalization than those with muscle pain, confusion, fatigue and other symptoms.
People reporting clusters 1, 2 and 3 were found to be much less likely to require breathing support, with only 1.5, 4.4 and 3.3 percent of each cluster respectively requiring help, the study said.
However, people in clusters 4, 5 and 6 were significantly more likely to require breathing support. Almost 20 percent of cluster 6 patients required breathing support, as did 8.6 and 9.9 percent of clusters 4 and 5 respectively.
Patients in cluster 6 were the most at risk, with nearly half ending up in hospital, compared to just 16 percent in cluster 1.
“These findings have important implications for care and monitoring of people who are most vulnerable to severe COVID-19,” Dr. Claire Steves, a consultant geriatrician and a member of the team working on the study said, according to the statement.
Old people experience more severe symptoms
The study also reported differences in symptoms based on age and pre-existing conditions.
People in clusters 4, 5 and 6 were also older, frailer and likely had pre-existing conditions such as diabetes, lung disease or were overweight, compared to clusters 1, 2 and 3, the study showed.
“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,” Steves added.
Using the cluster approach could allow for hospitals to better predict which patients are likely to require support sooner, and lead to greater health outcomes, the researchers said.
The COVID Symptom Study is run by Zoe Global Limited and King’s College London in collaboration with Guy’s and St Thomas’ Hospitals.