White House Chief Medical Advisor Anthony Fauci told reporters on Tuesday that the Omicron variant has yet to be detected in the United States.
The US surveillance system is in a much stronger position than when the Covid-19 Alpha variant appeared last year. At the start of this year, less than 1% of positive tests were sequenced and then reported to the Centers for Disease Control and Prevention before the agency pushed to expand its network of public, private and academic laboratories providing data.
The current surveillance effort in the United States is comparable to that of the European Union, said Phil Febbo, chief medical officer at DNA sequencing company Illumina, which works with the CDC.
“What we need to watch is consistency and make sure there are no pockets where we don’t get any input,” Febbo said.
The United States is now sequencing between 5 and 10 percent of positive cases – a level that can detect any variant that is one-hundredth of a percent of total cases, according to Becker. CDC director Rochelle Walensky told reporters that the number of sequenced positive tests – about 80,000 samples per week – represents one in seven positive cases by laboratory PCR.
The popularity of home antigen testing poses a challenge to public health officials struggling to understand the emergence of new variants, as many of the the results are not reported to the authorities.
“Unfortunately, we don’t yet have a system in place in our country to automatically sort some of these rapid tests – positive samples – to be sequenced,” the former director of the Biomedical Advanced Research and Development Authority told POLITICO, Rick Bright.
Another challenge is to ensure that the country tests and sequences a representative number of positive results from patients with mild or no symptoms.
“We might find that this variant of Omicron has been around for some time just under the radar because it wasn’t causing such severe disease, and we weren’t sequencing or monitoring these populations enough,” he said. said Bright, who is now the CEO of the Rockefeller Foundation’s Pandemic Prevention Institute.
The CDC is expanding a surveillance effort to test travelers at select international airports to more quickly detect cases of Covid-19 among those arriving in the United States, according to Walensky.
“The CDC is evaluating how to make international travel as safe as possible, including pre-departure testing closer to the time of flight and considerations for additional post-arrival testing and self-quarantine,” said Walensky.