Previous studies have shown that certain people are at a higher risk of contracting the coronavirus disease (COVID-19), while others are more likely to develop severe illness. People with underlying health conditions and the elderly are the most affected populations amid the coronavirus pandemic. Now, as the pandemic evolves, more information is available on who is at risk.
Now, a new study by researchers at AncestryDNA, a company that provides DNA testing services that use modern autosomal testing technology, shows that some people are more susceptible to COVID-19 infection, and they may experience more severe outcomes, including males, the elderly, and those with comorbidities.
Published as a preprint in the open-source journal medRxiv*, the study also highlights the importance of self-reported epidemiological data at scale to provide public health insights into the evolving COVID-19 pandemic.
The researchers aimed to assess the susceptibility and severity patterns in large datasets since the growing toll of the pandemic has increased the urgency of identifying those who are at most risk of severe illness.
The team collected data through the AncestryDNA COVID-19 Study’s self-reported survey on symptoms, outcomes, risk factors, and exposures for more than 500,000 adults in the United States, the hardest-hit country of the pandemic, topping a case toll of more than 7.80 million.
Of these adults, there were more than 4,700 COVID-19 cases as measured by a self-reported nasal swab test. Self-reported survey data, which can be easily collected at home, provide a convenient way to monitor the evolving pandemic. It also allows for real-time estimation of individual-level COVID-19 risk.
After collecting the survey data from more than half a million participants in the country, the team has found that known exposure differences account for many linkages for a positive COVID-19 test result. The team also revealed that males might be more susceptible to COVID-19 infection than females, even after adjusting for known exposures and age.
Further, the team noted that their findings mirror previous studies that link certain medical conditions, age, and COVID-19 severity.
Susceptibility and severity
Interestingly, the team also revealed that younger individuals are more likely to test positive for COVID-19 than older people. Perhaps it may be because this age group is part of the workforce, while older adults were advised to isolate themselves and stay at home to prevent infection.
They further said that people who reported that they have pre-existing medical conditions such as cardiovascular disease, diabetes, hypertension, cancer, and chronic kidney disease were less likely to test positive for COVID-19. They found that there were decreased odds of a known “direct” exposure to COVID-19.
However, though they have a decreased risk of being infected, once they contract the virus, they have a higher risk of developing a critical illness.
Specific underlying medical diseases that were tied to hospitalization or critical case progression included chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), diabetes, hypertension, and cardiovascular disease. Aside from these individuals, older adults were more likely to be hospitalized than those who are between 50 and 64 years old.
Symptoms and COVID-19
Lastly, the team said that the symptoms present most strongly tied to a positive test result are different from the symptoms most strongly associated with disease severity.
Among the adults who developed symptoms, those who reported moderate to a severe change in smell and taste, fever, and fatigue were more likely to test positive for COVID-19. On the other hand, those who reported moderate to a severe runny nose or sore throat were more likely to test negative, indicating that these symptoms are due to common colds or influenza infection.
The hallmark symptom of COVID-19 infection, the change in smell or taste, was not tied to hospitalization. Meanwhile, shortness of breath or dyspnea was the most predictive of hospitalization and eventually critical case progression, but was not linked to a positive test result.
“The study highlights the exposure burden as the primary risk factor for COVID-19 susceptibility, and the importance of accounting for known exposures when assessing differences in susceptibility to COVID-19,” the researchers wrote in the paper.
The researchers underline the importance of self-reported datasets in gaining more understanding of the COVID-19 pandemic. The AncestryDNA COVID-19 Study provides a highly complete, self-reported dataset that provides information on risk factors, susceptibility, and severity outcomes in those infected with the virus.
“The large AncestryDNA network, well-established data collection mechanisms, and willingness of AncestryDNA customers to participate in COVID-19 research have rapidly come together in this study to elucidate more details about susceptibility and severe disease risk factors and help point the way to minimizing disease burden,” the researchers concluded.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.