COVID-19: Over 80% of young people may show no symptoms

A preliminary study suggests that more than 80% of people aged 20 and under may show no symptoms after contracting SARS-CoV-2. This may have important implications for virus transmission.

Experts from the Bruno Kessler Foundation in Trento, Italy, in collaboration with colleagues affiliated to the ATS Lombardy COVID-19 Task Force and various research institutions, conducted a study assessing what percentage of people who have contracted SARS-CoV-2 are likely to experience any symptoms.

This preliminary study does not yet appear in a peer-reviewed journal, but its authors have made their findings available online, on the preprint platform arXiv.

The rate of likely asymptomatic carriers of the coronavirus could have important implications for viral transmission, the study authors point out.

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“This work allows us to clearly show the difficulties in identifying infections with surveillance since the majority of these are not associated with respiratory symptoms or fever,” says study co-author Stefano Merler, who specializes in mathematical modeling of infectious disease transmission.

The researchers analyzed data on 5,484 individuals from the Lombardy region of Italy who had been in contact with people with a new coronavirus infection. Of these, 2,824 individuals had laboratory-confirmed SARS-CoV-2 infections.

Looking at the data, the investigators found that, of the 2,824 individuals with known coronavirus infections, only 876 (31%) had presented any symptoms.

Looking at data on age, the researchers calculated that, among people aged 20 years and under, a probable 81.9% would present no symptoms following infection with the coronavirus.

Among those 80 years of age or over, the investigators estimate that only 35.4% are likely to show no symptoms following infection with the new coronavirus.

Among individuals with a confirmed SARS-CoV-2 infection who were 60 years old and under, 73.9% were likely not to experience fever — body temperature of at least 37.5oC — or respiratory symptoms, the study authors noted.

In terms of general trends, the researchers concluded that the likelihood of experiencing SARS-CoV-2 infection symptoms increased with age.

They also noted that 6.6% of people aged 60 years and older had a severe form of COVID-19 as a result of contracting the new coronavirus, and males had a “significantly higher risk” than females of experiencing a critical state.

Part of what makes the current study important, according to Merler, is that it “also represents a useful piece of information to better understand the role of children in the epidemiology of COVID-19, which we still know very little about.”

“Everyone knows that few positive children were identified during the pandemic,” he says, “but this study allows us to determine the contribution of a possible lower susceptibility to infection in children, which we had identified in a previous study conducted in China, compared to the probability of developing clinical symptoms once infected.”

Source: MedicalNews Today

35% of excess deaths from pandemic not caused by COVID-19

New research suggests that in the United States, around 35% of excess deaths during the early phase of the pandemic were not directly caused by COVID-19.

A new study has found that in the U.S., up to 35% of excess deaths during the early phase of the pandemic may not have been directly due to COVID-19.

The research, which now appears in the journal JAMA, suggests that experts may have underestimated the pandemic’s death toll in publicly reported deaths.

COVID-19 and mortality

In severe cases, COVID-19 can cause pneumonia: The body’s inflammatory response overcompensates for the presence of the virus in the lungs, reducing the lungs’ ability to get oxygen into the blood.

This can, in turn, lead to organ failure or serious cardiovascular events and, ultimately, death.

However, as well as the direct effects of COVID-19 on a person’s body, the virus can also cause death by exacerbating underlying health issues; the body’s immune system is weakened while fighting off the illness.

Furthermore, the sudden emergence and rapid spread of the disease overwhelmed critical care units when the virus was at its peak, reducing the amount of care any individual patient could receive. This affected not only COVID-19 patients but all those who may have needed critical care.

Consequently, the effect of the pandemic on excess deaths — that is, the number of additional deaths beyond what experts expect of a country during a given time — may be greater than what experts have typically reported, particularly if those reports relied on deaths directly attributed to COVID-19.

Excess deaths

This was the finding of a new study that explored the attribution of cause of death for the excess deaths in the U.S. during the early phase of the COVID-19 pandemic.

The study found that death toll reports attributed only 65% of the excess deaths in the U.S. to COVID-19.

Furthermore, in 14 states — including California and Texas, which have large populations — reports linked less than 50% of excess deaths directly to COVID-19.

For lead study author Prof. Steven Woolf, director emeritus of Virginia Commonwealth University’s Center on Society and Health in Richmond, this may mean that experts have underestimated the death toll of the pandemic.

According to Prof. Woolf: “There are several potential reasons for this under-count. Some of it may reflect under-reporting; it takes a while for some of these data to come in. Some cases might involve patients with COVID-19 who died from related complications, such as heart disease, and those complications may have been listed as the cause of death rather than COVID-19.”

“But a third possibility, the one we’re quite concerned about, is indirect mortality — deaths caused by the response to the pandemic. People who never had the virus may have died from other causes because of the spillover effects of the pandemic, such as delayed medical care, economic hardship, or emotional distress.”

– Prof. Steven Woolf

The study also found that excess deaths not linked to COVID-19 rose significantly in states that had the largest outbreaks of the disease during the virus’s peak in early April. These included Massachusetts, Michigan, New Jersey, New York, and Pennsylvania.

For example, in these states, there were 96% more diabetes-related deaths than experts predicted. For heart disease, the figure was 89%; for Alzheimer’s disease, it was 64%; and for stroke, it was 35%.

As well as people not being able to get the necessary treatment due to hospitals being overloaded, the study authors also speculate that people may have stayed at home due to the virus despite experiencing worsening symptoms of another condition they may have had.

They also believe that the pandemic’s effects on people’s mental health may have played a part.

As Prof. Woolf notes: “We can’t forget about mental health. A number of people struggling with depression, addiction, and very difficult economic conditions caused by lockdowns may have become increasingly desperate, and some may have died by suicide. People addicted to opioids and other drugs may have overdosed.”

“All told, what we’re seeing is a death count well beyond what we would normally expect for this time of year, and it’s only partially explained by COVID-19.”

These findings are particularly important, as new cases of the virus are beginning to surge after the relaxation of physical distancing rules in various states across the U.S.

For Prof. Woolf, “[p]ublic officials need to be thinking about behavioral healthcare and ramping up their services for those patients in need. The absence of systems to deal with these kinds of other health issues will only increase this number of excess deaths.”

Source: MedicalNews Today