Findings of a latest study from the UK suggest that early Covid-19 symptoms vary among various age groups. Also, men and women report different symptoms in the early stage of Covid-19.

Researchers at Kings College London analysed data from the ZOE Covid-19 Symptom Study App from April 20 to October 15, 2020 and published their findings July 29, 2021 in The Lancet Digital Health.¹

The App collected self-reported data on 19 symptoms and COVID-19 PCR test results. But for this study, 18 of these self-reported symptoms were examined and evaluated for their ability to predict early detection of Covid-19.

Overall, loss of smell, chest pain, persistent cough, shortness of breath, abdominal pain, blisters on the feet, eye soreness and unusual muscle pain were the most relevant symptoms to detect Covid-19. Heart disease, followed by kidney disease, and lung disease were the comorbidities that had the highest relevance to the detection of the infection.

Men were more likely to report shortness of breath, fatigue, chills or shivers, whereas women were more likely to report loss of smell, chest pain and a persistent cough. Loss of smell, chest pain and abdominal pain were highly predictive of a positive COVID-19 test for both men and women.

Significant differences in the relevance of all symptoms between different age groups (16–39 years, 40–59 years, 60–79 years, ≥80 years) were noted.

The most significant symptoms in 16–39 year age group in order of relevance were loss of smell, chest pain, abdominal pain, shortness of breath and soreness in eye. Persistent cough was more relevant to the diagnosis of Covid-19 in the 40–59 year age group. In persons aged 60-79 years, the important symptoms were chest pain, unusual muscle pain, shortness of breath and loss of smell.

The most relevant symptoms in individuals aged ≥80 years were diarrhea, sore throat, chest pain, unusual muscle pain, eye soreness and chills or shivers.

This shows that loss of smell as a symptom predictive of Covid-19 was more important in the younger age group. Loss of smell was not so significant in ≥60 years and was not relevant for those aged 80 years or older. Diarrhea was an important early symptom in ≥80 year age group, but not in others. What is also interesting to note is that fever was not an early symptom in any of the age groups.

Data was also analysed for healthcare workers and non-healthcare workers. Results showed that the early symptoms in healthcare workers were chills or shivers, persistent cough, headache, and chest pain as highly relevant symptoms followed by unusual muscle pain, diarrhoea, fatigue, and skipped meals. In non-healthcare workers, the most relevant early symptoms were chest pain, persistent cough and blisters on the feet. Loss of smell was found to be the most relevant feature for early diagnosis of Covid-19 common to both groups.

A wide variety of presenting symptoms of Covid-19 have been reported in the last one and half years of the pandemic. But, early symptoms can vary even amongst family members as shown in this study.

While, this study has taken into consideration 18 symptoms, any new and even unusual symptom particularly during Covid time should be thought of as due to Covid-19 unless proved otherwise. Not all patients present with the classical symptoms of dry cough, fever or breathlessness. It is therefore important to be alert and watchful. This will help in early detection of cases and timely management, including self-isolation and prevent further transmission of infection.

Reference: Canas LS, et al. Early detection of COVID-19 in the UK using self-reported symptoms: a large-scale, prospective, epidemiological surveillance study. Lancet Digit Health. Published: July 29, 2021. DOI:https://doi.org/10.1016/S2589-7500(21)00131-X