A persistent cough and fever have been confirmed as the most prevalent symptoms associated with COVID-19, according to a major international review of patient data. Other major symptoms include fatigue, losing the ability to smell and difficulty in breathing. The study ratifies the list of symptoms compiled by the World Health Organisation at the start of the pandemic.

A team of researchers including a final year medical student from the University of Sheffield combined data from 148 separate studies, to identify the common symptoms experienced by more than 24,000 patients from nine countries including the UK, China and the U.S.

The study -- published in the online journal PLoS One -- is one of the biggest reviews, or meta analysis, ever conducted into COVID-19 symptoms.

Of the 24,410 cases, the study found:

• 78 percent had a fever. Although this tended to vary across countries, with 72 percent of fever reported by patients in Singapore and 32 per cent in Korea.
• 57 percent reported a cough. Again, this varied across countries, with 76 percent of patients reporting a cough in the Netherlands compared to 18 percent in Korea.
• 31 percent said they had suffered fatigue.
• 25 percent lost the ability to smell.
• 23 percent reported difficulty breathing.

The researchers believe the variation in the prevalence of symptoms between countries is due, in part, to the way data was collected.

Of those patients who needed hospital treatment, 17 percent needed non-invasive ventilation; 19 percent had to be looked after in an intensive care unit, 9 percent required invasive ventilation and 2 percent needed extracorporeal membrane oxygenation (an artificial lung).

Michael Grant, a final year medical student from the University of Sheffield, said, “The impact of COVID-19 on daily activities has been immense. An accurate estimation of symptom prevalence, as provided by this study, is essential to combat COVID-19. As a medical student, it has been a tremendous opportunity and a great privilege to contribute to research that will be used to inform public health opinion.”

Ryckie Wade, a surgeon and clinical research fellow at the Leeds Institute of Medical Research, who supervised the research, said, "This analysis confirms that a cough and fever were the most common symptoms in people who tested positive with COVID-19. This is important because it ensures that people who are symptomatic can be quarantined. The study gives confidence to the fact that we have been right in identifying the main symptoms and it can help determine who should get tested."

The study involved academics from the University of Leeds with colleagues from the University of Sheffield, University of Bristol, Imperial College, London, and the Belgium Cancer Centre. The research was funded by the UK's National Institute for Health Research and VALCOR, in Belgium. The researchers acknowledge there are people who had the virus but did not display any symptoms.

Source: University of Sheffield