September 29, 2020 by John Fernandez
COVID-19 Roundup: Actual Cases 6 to 24 Times Higher (CDC); Older Kids Can Spread Virus; and ‘Sample Pooling’ Approved
Actual COVID-19 Positive Count is Likely 6 to 24 Times Higher Than Official Estimates, CDC Says
The actual number of COVID-19 cases in the U.S. could be from six to 24 times higher than the official number, according to a government study that used data from 10 U.S. cities and states.
The true number of cases depends on the region and the time period, according to an analysis of the findings released by the U.S. Centers for Disease Control and Prevention (CDC). In seven of the 10 regions, the estimated number of cases was at least 10 times higher than the number of reported cases.
The study, published this week in JAMA Internal Medicine, relied on serological tests — blood screens that search for antibodies to the coronavirus to determine whether someone was previously infected. Diagnostic tests only detect people who are currently infected with COVID-19.
The study’s findings are based on serological tests from more than 16,000 people across the 10 regions, but most of the samples were taken in late March, April or May.
In South Florida, researchers estimated that 2 percent of the population had antibodies to the corona virus — meaning that actual positive cases were 11 times higher than the official count. But the samples used for the study were taken in early April, before the spike in cases over the past several weeks — so the percentage would certainly be higher now, researchers says. In New York, the CDC estimates indicated that 642,000 people were infected by April 1. However, at that time only 53,803 cases were reported by New York officials.
The study’s authors conclude: “The findings may reflect the number of persons who had mild or no illness, or who did not seek medical care or undergo testing but who still may have contributed to ongoing virus transmission in the population.”
New Study: Children, 10-19 Years of Age, Can Spread Coronavirus as Much as Adults
Children and teenagers between the ages of 10 and 19 can spread the coronavirus at least as well as adults can, according to a large-scale new study from South Korea published by the U.S. Centers for Disease Control and Prevention (CDC).
Researchers also found that children younger than 10 can transmit the virus to others much less often than adults do — but there’s still a risk of spreading COVID-19 among these younger kids.
Data from contact tracing in South Korea was studied by researchers. They analyzed thousands of contacts of about 5,700 coronavirus patients (from January through March of 2020). They focused on the age of the first infected person in a household. In homes where the first person infected in a cluster was 10 to 19 years of age, about 19 percent of their household contacts got COVID-19. In contrast, only 5 percent of the household contacts of younger children, up to 9 years of age, were known to be infected. Schools were closed in South Korea during the period of the study.
The first person in a household to experience symptoms is not necessarily the first to have been infected, researchers conceded. Moreover, kids are also less likely than adults to show symptoms. So experts say the number of children who started the chain of transmission within their households may be underestimated.
“Given the high infection rate within families, personal protective measures should be used at home to reduce the risk for transmission — if feasible,” the study concludes. Despite the study’s findings, kids overall tend to get infected with the coronavirus less often and have milder symptoms, compared to adults.
FDA Authorizes ‘Sample Pooling’ in Diagnostic Testing for COVID-19
The U.S. Food and Drug Administration has given “emergency use authorization” to Quest Diagnostics to use pooled samples containing up to four individual swab specimens collected from persons being tested for COVID-19.
The test is the first COVID-19 diagnostic test to be approved for use with pooled samples. The FDA states that “sample pooling” is an important public health tool. “It allows for more people to be tested quickly using fewer testing resources. Sample pooling does this by allowing multiple people – in this case four individuals – to be tested at once,” the FDA said in a news release.
The samples collected from the four individuals are then tested in a pool or “batch” using one test, rather than running each individual sample on its own test.
If the pool is “positive” — meaning that one or more of the individuals tested in that pool may be infected — then each of the samples in that pool are tested again individually, the FDA explained. Because the samples are pooled, fewer testing supplies are used and more tests can be run at the same time — allowing patients to receive their results more quickly in most cases, the FDA says.
This testing strategy is “most efficient in areas with low prevalence, meaning most results are expected to be negative,” the agency said.