Study: 20-to-49 Age Group a ‘Main Driver’ of COVID-19 Spread Across the U.S.
Public health officials have said for months that young adults seem to be fueling much of the COVID-19 transmission. Now, researchers have pinpointed a certain age group. Adults aged 20 to 49 represent a “main driver” of the COVID-19 pandemic in the U.S., and account for nearly two-thirds of new cases nationwide, says a study published in Science  by researchers from the Imperial College London.
Researchers based their findings on aggregated, age-specific mobility data from more than 10 million individuals in the U.S. They then compared that location data to COVID-19 case and mortality rates by age.
“We believe this study is important because we demonstrate that adults aged 20 to 49 are the only age groups that have consistently sustained COVID-19 spread across the U.S., despite large variations in the scale and timing of local epidemics,” said Oliver Ratmann, M.D., a co-author of the study, in a news release from Imperial College London.
The mobility data, which tracks the location and movement of people based on information from cellphones and other mobile devices, revealed that 65 of every 100 COVID-19 U.S. infections in the country through the end of October originated in adults aged 20 to 49. The most significant spikes in coronavirus spread were among adults aged 35 to 49 after the reopening of schools in many states, researchers said.
As of October 2020, persons aged 20 to 49 represented the only group “sustaining COVID-19 transmission with reproduction numbers well above 1 in the U.S.,” the researchers said in a statement. A reproduction number refers to the average number of persons to whom an infected person spreads COVID-19.
“Targeting interventions – including transmission-blocking vaccines – to adults aged 20-49 is an important consideration in halting resurgent epidemics and preventing COVID-19-attributable deaths,” the study states.
CDC Issues Mandatory Mask-Wearing Order for Everyone Taking Public Transportation
The U.S. Centers for Disease Control and Prevention has issued an order  requiring everyone to wear masks while using public transportation to enter the U.S. and travel throughout the country. The order, which took effect at midnight Monday, applies to both passengers and workers on public forms of transport, such as airplanes, ships, ferries, trains, subways, buses, taxies and ride shares.
“People must wear masks that completely cover both the mouth and nose while awaiting, boarding, disembarking, or traveling on airplanes, ships, ferries, trains, subways, buses, taxis, and ride-shares as they are traveling into, within, or out of the United States and U.S. territories,” the CDC states.
The order covers required mask-wearing at airports, bus and ferry terminals, seaports, and train and subway stations, states the CDC. The CDC issued the order based on President Joe Biden’s executive action requiring mask-wearing on public transportation.
Exceptions to the order include children under 2 and people who cannot safely wear a mask due to a disability. Face masks can be removed while eating, drinking or taking medication. A mask is not required when communicating with a person who is hearing impaired. Masks can be either “manufactured or homemade,” and can be “reusable or disposable,” the CDC said.
Face shields or goggles “may be worn to supplement a mask that meets … required attributes,” the agency said.
U.S. airlines had already established their own mandatory mask requirements.
“Requiring masks on our transportation systems will protect Americans and provide confidence that we can once again travel safely even during this pandemic,” states the order, signed by Martin Cetron, M.D., director of the CDC’s Division of Global Migration and Quarantine. “Therefore, requiring masks will help us control this pandemic and aid in re-opening America’s economy.”
Pandemic’s Impact on Heart Surgery Volume in U.S. was Substantial, Researchers Find
The COVID-19 pandemic in the U.S. resulted in a significant decline in heart surgeries last year, and “an unexplained increase in deaths” after coronary artery procedures, according to research presented at the 57th Annual Meeting of The Society of Thoracic Surgeons.
The researchers reviewed data from 717,103 adult cardiac surgery patients from January 1, 2018 to the end of 2020. The study found an overall 53 percent decrease nationwide in all adult cardiac surgery volume when compared to 2019, and 65 percent fewer elective cases in the U.S.
The research did not directly address the cause of increased mortality, but many surgeons said that operating only on the most urgent coronary bypass cases — and on patients who tend to be sicker — likely contributed to the increase in deaths last year.
Many planned surgical procedures were postponed early in the pandemic to protect vulnerable patients from infection. When these procedures resumed later in the year, their numbers never quite reached the pre-COVID levels, researchers said.
“These numbers should not serve as a deterrent to patients seeking care for chest pain or other cardiac symptoms,” said Robbin G. Cohen, M.D, from Keck School of Medicine of the University of Southern California in Los Angeles, who was not directly involved with this study. “If anything, they are a warning to get into the system as soon as possible.”