|
 The U.S. Food and Drug Administration has expressed concerns over
the safety of self throat swabbing.
People can already transmit Omicron to others when it has infected
their throat and saliva but before the virus reaches their nose, so
swabbing the nostrils too early in the course of infection will not
pick it up, Dr. Michael Mina, formerly of the Harvard T.H. Chan
School of Public Health and now chief science officer at eMed, said
during a news conference on Thursday.
A study released on Wednesday on medRxiv ahead of peer review looked
at 29 Omicron-infected workers in high-risk professions who had PCR
and antigen tests done simultaneously on multiple days. The PCR
tests of saliva detected the virus on average three days before the
rapid nose-swab samples became positive.
"When people test negative by rapid antigen, they can still have
very infectious viral loads and transmit to other people," said
study leader Blythe Adamson of New York-based risk reduction company
Infectious Economics LLC.
A positive antigen test is very reliable, Mina noted.
On social media, some experts have advised antigen-test users to
swab the throat before swabbing the nose. The FDA, however, said
users should follow manufacturers' instructions.
The agency said there are safety concerns regarding self-collection
of throat swabs, "as they are more complicated than nasal swabs, and
if used incorrectly, can cause harm to the patient."
[to top of second column] |
 "The CDC recommends that throat
swabs be collected by a trained healthcare
provider," the FDA said.
Before the FDA would approve at-home throat
swabbing, manufacturers would need to conduct
studies to show that consumers could safely
perform the tests, and provide detailed
instructions with each test kit, Mina said,
adding that people go against the FDA's advice
"at their own risk."
He noted that testing kits provided to consumers
in the UK do include instructions for swabbing
the throat. While it is important to follow the
FDA's guidance, he said, "we also need to follow
the science."
Research shows that COVID-19 symptoms appear
earlier with Omicron than with other variants.
"When you feel symptoms, assume you're
positive," but wait to use the antigen tests
until a few days have passed, advised Mina,
whose company develops technology to verify
antigen test results.
The tests "are detecting Omicron just fine" once
it has invaded the nose, he said.
(Reporting by Nancy Lapid; Editing by Michele
Gershberg and Bill Berkrot)
[© 2022 Thomson Reuters. All rights
reserved.]
This material may not be published,
broadcast, rewritten or redistributed.
Thompson Reuters is solely responsible for this content. |
