COVID-19 Scan for Jun 23, 2021

News brief

US COVID-19 cases in first pandemic wave may have been 5 times higher

During the first US wave of the COVID-19 pandemic, there may have been almost 17 million undiagnosed COVID-19 infections in addition to the known 3 million cases, or about five times more than officially reported, according to a study in Science Translational Medicine yesterday.

The researchers conducted enzyme-linked immunoassay serologic tests for COVID-19 antibodies on 8,058 undiagnosed US adults from May 10 to Jul 31, 2020, and found that 304 (4.6%) had COVID-19 antibodies. This indicates that there were 4.8 undiagnosed infections for every diagnosed case during this period, the researchers say, adding about 16.8 million infections to the country's total.

The cohort was designed to reflect the US population.

Data showed that 14.2% of Black people had COVID-19 antibodies, compared with 2.5% of White people and 2.0% of Asian people. The mid-Atlantic region had the highest rate of people with COVID-19 antibodies (8.6%); higher rates were also found among city dwellers (5.3% vs 1.1% in the country), those under 45 (5.9%), and women (5.5% vs 3.5% in men). Those who worked from home (3%) and those with chronic conditions had the lowest levels of antibodies in their blood.

"Our data suggest a larger spread of the COVID-19 pandemic in the United States during the first six months than originally thought," the researchers write. "Our findings have implications for understanding SARS-CoV-2 spread, epidemiological characteristics of spread and prevalence in different communities, and could have a potential impact on decisions involved in vaccine rollout."
Jun 22 Sci Transl Med study

Young adults with mild acute infection may be at risk for long COVID

More than 60% of 312 COVID-19 patients had symptoms persisting after 6 months, including 52% of older teens and young adults with mild acute infections, according to a Nature Medicine study today.

The cohort consisted of 312 patients from Bergen, Norway, identified from Feb 28 to Apr 4, 2020, or about 82% of the city's total cases. About 80% were outpatients and the remaining were hospitalized; the median age was 46 years. Those hospitalized tended to be older, have a higher body mass index, and have more comorbidities.

At 6 months follow-up, 61% still experienced symptoms, which were independently associated with pre-existing chronic lung disease (eg, asthma; adjusted risk ratio [aRR], 1.14), female sex (aRR, 1.09), higher antibody titers at 2 months (aRR, 1.07), and severity of the acute illness (aRR, 1.06). Younger patients were less likely to have long COVID symptoms, but the researchers say that 52% of 61 outpatients from 16 to 30 years experienced some sort of symptom, most commonly loss of taste and/or smell (17), fatigue (13), shortness of breath (8), impaired concentration (8), and memory problems (7).

"It is worrying that non-hospitalized, young people (16–30 years old) suffer potentially severe symptoms, such as concentration and memory problems, dyspnea and fatigue, half a year after infection," the researchers write. "Particularly for students, such symptoms might interfere with their learning and study progress."
Jun 23 Nature Med study

News Scan for Jun 23, 2021

News brief

CWD detected in a deer from another Wisconsin county

Chronic wasting disease (CWD) has been detected in an adult deer found dead in early May in the Wisconsin city of Brooklyn, marking the state's first such case in Green Lake County, the Wisconsin Department of Natural Resources (WDNR) said late last week.

Green Lake County is in central Wisconsin, and the location of the deer is within 10 miles of neighboring Fond du Lac, Winnebago, and Waushara counties. The new detection makes Winnebago County a CWD-affected county, triggering a 2-year ban on baiting and feeding deer that takes effect on Jul 1. Green Lake, Fond du Lac, and Waushara counties—being in a 10-mile radius of an earlier CWD or tuberculosis case—already have baiting and feeding bans in place.

CWD is a fatal prion disease that affects deer, elk, and other cervids, and has affected 26 US states and 3 Canadian provinces. No cases have yet been reported in people, but some experts fear that it could jump to humans and cause a disease similar to bovine spongiform encephalopathy (BSE, or "mad cow" disease). Health officials urge people avoid eating meat from infected animals.
Jun 18 WDNR press release

Texas expands CWD movement ban to more deer breeders

Texas wildlife officials yesterday announced an emergency order imposing more movement restrictions on deer-breeding facilities linked to six breeders where CWD was detected. Current rules already limit deer movement from 264 sites in 95 counties with direct links to the facilities. In a statement, Texas Parks and Wildlife (TPW) said further measures are needed because of the seriousness of the situation.

The emergency order also comes with enhanced testing requirements for facilities with close epidemiologic links to the CWD-positive facilities and antemortem (live-deer) testing of all movement-qualified deer breeding farms before transfer to a release site. Officials said the steps are needed to reduce the risk of CWD spreading into the state's free-range whitetail deer population and to protect the captive deer-breeding industry.

CWD was first detected in Texas in 2012 in mule deer and has now been detected in 228 captive or free-range cervids, including white-tailed deer, red deer, and elk in 13 of the state's counties.

In May, CWD was found for the first time in Matagorda and Mason counties, both in deer-breeding facilities. Both that had received animals from a breeder in Uvalde County.
Jun 22 TPW statement
May 18 CIDRAP News scan