Young Americans in 20s now account for 1 in 5 Covid-19 cases, CDC says they likely contribute to transmission
Health experts have been warning that coronavirus cases are rising among the young and a new analysis reveals that young adults in their 20s now represent 1 in every 5 cases in the US. During June-August, Covid-19 incidence was highest in persons aged 20-29 years, who accounted for more than 20% of all confirmed cases, according to the US Centers for Disease Control and Prevention (CDC). The findings indicate that younger adults likely contribute to community transmission of Covid-19, write authors. They suggest that strict adherence to community mitigation strategies and personal preventive behaviors by younger adults is needed to help reduce their infection and minimize subsequent transmission to persons at higher risk for severe illness.
“The new report shows why young adults should take steps to slow the spread, such as wearing masks and avoiding in-person gatherings. From June to August, adults in their 20s had the highest rate of Covid-19 infections, accounting for 1 of every 5 cases. Increased prevalence of SARS-CoV-2 (the virus that causes Covid-19) infection among younger adults likely contributes to community transmission of Covid-19, including to persons at higher risk for severe illness, such as older adults,” says the report.
Cases are also rising among children (age ranges vary from 0 to 20 years) in the US. While children represented 10.3% of all cases in states reporting cases by age as of September 17, over 587,000 children have tested positive for Covid-19 since the onset of the pandemic. An estimated 74,553 new child cases were reported between September 3 to September 17 (513,415 to 587,948), which is a 15% increase over two weeks, according to the American Academy of Pediatrics and the Children’s Hospital Association. “At this time, it appears that severe illness due to Covid-19 is rare among children. However, states should continue to provide detailed reports on Covid-19 cases, testing, hospitalizations, and mortality by age and race/ethnicity so that the effects of coronavirus on children’s health can be documented and monitored,” suggest experts.
The findings come even as the CDC is warning that a majority of the US remains susceptible to coronavirus infection. During a recent hearing, CDC director, Dr Robert Redfield, said, “The preliminary results in the first round show that a majority of our nation more than 90% of the population remains susceptible. It varies in different geographic parts from states that have less than one percent with evidence of previous infection, to some that have more than 15, 20, and one as high as 24%.”
The analysis
Early in the pandemic, Covid-19 incidence was highest among older adults. The CDC examined the changing age distribution of the Covid-19 pandemic in the US during May-August by analyzing coronavirus-like illness-related emergency department (ED) visits, positive test results for SARS-CoV-2, and confirmed Covid-19 cases.
The team found that the national incidence of confirmed coronavirus increased from 185 cases per 100,000 persons in May to 316 in July, then declined to 275 in August. During May-July, incidence increased among persons in all age groups less than 80 years of age, with the largest increases in persons aged less than 30 years. As a result, the median age of confirmed Covid-19 cases decreased from 46 years in May to 37 years in July and 38 years in August. Similar patterns were seen for Covid-19-like illness-related ED visits and positive SARS-CoV-2 test results in all US Census regions. During June-August, persons aged 20-29 years accounted for the largest proportion of total cases. Similar age shifts were observed nationwide, say authors.
“During June-August, the Covid-19 pandemic in the US affected a larger proportion of younger persons than during January-May. The shift toward younger ages occurred in all four US Census regions, regardless of changes in incidence during this period. A similar age shift occurred in Europe, where the median age of Covid-19-19 cases declined from 54 years during January-May to 39 years during June-July, during which time persons aged 20-29 years constituted the largest proportion of cases (19.5%),” the findings state.
The investigators further say that during the study period, the southern US experienced regional outbreaks of Covid-19 in June. In these regions, increases in the percentage of positive SARS-CoV-2 test results among adults aged 20-39 years preceded increases among adults aged 60 years and above by an average of 8.7 days (range of 4-15 days), providing “preliminary evidence that younger adults contributed to community transmission of Covid-19 to older adults”.
What are the implications?
According to the research team, occupational and behavioral factors might put younger adults at higher risk for exposure to Covid-19. They argue that younger adults make up a large proportion of workers in frontline occupations — such as retail stores, public transit, child care, and social services — and highly exposed industries (restaurants/bars, entertainment and personal services), where the consistent implementation of prevention strategies might be difficult or not possible. Besides, younger adults might be less likely to follow community mitigation strategies, such as social distancing and avoiding group gatherings, they add.
The study also warns that younger adults, who are more likely to have mild or no symptoms can unknowingly contribute to presymptomatic or asymptomatic transmission to others, including to persons at higher risk for severe illness. The experts caution SARS-CoV-2 infection is not benign in younger adults, especially among those with underlying medical conditions, who are at risk for hospitalization, severe illness, and death.
“Emphasis should be placed on targeted mitigation strategies to reduce infection and transmission among younger adults. This includes age-appropriate prevention messages, restricting in-person gatherings and events, recommending mask use and social distancing in settings where persons socialize, implementing safe practices at on-site eating and drinking venues, and enforcing protection measures for essential and service industry workers,” the researchers recommend. “Given the role of asymptomatic and presymptomatic transmission, all persons, including young adults, should take extra precautions to avoid transmission to family and community members who are older or who have underlying medical conditions,” they conclude.