Older age, being male and underlying conditions such as cardiovascular diseases are already known risk factors associated for Covid-19. But now, the scientists have identified, deprivation, living in a densely populated area, ethnicity, obesity, and chronic kidney disease as also likely risks associated with the Coronavirus. These observations have been published in The Lancet Infectious Diseases journal.
Moreover, previous studies have focused on the risk of severe COVID-19 in hospital cases; this new study, however, identifies risk factors for testing positive for COVID-19 using electronic health record data from General Practitioners .
Older age, being male, deprivation, living in a densely populated area, ethnicity, obesity, and chronic kidney disease (CKD) are seven factors associated with a positive test for COVID-19, according to results from 3,802 people tested for SARS-CoV-2 (including 587 positive tests) in the UK.
The study holds importance in the context of India too where a large number of cases have started pouring from slum areas like Dharavi in Mumbai which are heavily populated. Dharavi has already reported over 1,200 positive cases so far. Covid-19 positive cases are being reported from other slums too from various States. Moreover, India has a large number of people suffering with CKD.
Study author Professor Simon de Lusignan from the University of Oxford, and Director of the Royal College of GPs Surveillance Centre, UK, said: "While clear trends have emerged from hospital data for the people with severe symptoms, the risk of infection among the general population remains a grey area. It's important to know which groups in the wider community are most at risk of infection so that we can better understand SARS-CoV-2 transmission and how to prevent new cases."
The authors noted that other socio-economic factors, which were not measured in this study, may also be linked with SARS-CoV-2 infection, such as employment in high risk jobs, education, income, and differences in access to healthcare and testing among ethnic groups. Further research is needed to understand these associations.
Professor de Lusignan said: "This result does not indicate that smoking protects against infection, and there are many potential alternative explanations - such as smoking hampering the sensitivity of the SARS-CoV-2 test, or people who smoke being more likely to have an ongoing cough so being more likely to be tested despite not having the virus.
“As well as the well-documented harms to overall health from smoking, there is potential for smoking to increase the severity of COVID-19 disease, and so our findings should not be used to conclude that smoking prevents SARS-CoV-2 infection, or to encourage ongoing smoking."
The authors analysed data from 587 people with positive results and 3,215 with negative results, collated by GP practices in England who are part of the Royal College of General Practitioners Research and Surveillance Centre primary care network.
Among adults, those aged 40 to 64 years were at the greatest risk of testing positive for SARS-CoV-2 (18.5 per cent tested positive, 243 out of 1,316 people), compared with children aged up to 17 years (4.6 per cent, 23 of 499). Among 1,612 men, 18.4 per cent (296) tested positive, compared with 13.3 per cent (291/2,190) of women, said the study funded by Wellcome Trust.
There was a large difference between people living in the most and least deprived areas too as well in urban vs rural areas. Co-author Dr Gayatri Amirthalingam, from Public Health England, said: "With each day that passes our knowledge of COVID-19 improves.
This analysis of primary care outcomes of individuals testing positive for virus is an important contribution to our wider understanding of how COVID-19 is affecting people of different demographic groups.”
The authors suggested that a larger population survey is urgently needed to confirm which groups are most at risk.
