People are sharing Covid tests amid Omicron and experts want you to stop

Families sharing dwindling supplies of at-home rapid Covid test kits amid the Omicron surge are being warned of unreliable results.

Sticking swabs up multiple noses before placing samples on the test cards could produce false-negative results by diluting a virus sample, Susan Butler-Wu, a clinical microbiologist at the University of Southern California’s Keck School of Medicine, told The Atlantic.

The warnings come as families are reportedly using a single kit to test multiple people before going to group events. A positive result would let the families know at least one person has Covid, if not being able to determine the exact person infected.

The issue is, Ms Butler-Wu told writer Rachel Gutman, that false negatives can occur when too many human cells from more than one nose can dilute the positive sample from a person that is infected.

It can also spread Covid to someone who may not have had the virus to begin with and could have otherwise avoided contracting it from within the family.

Jennifer Nuzzo, a senior scholar at the Johns Hopkins Center for Health Security, told the outlet that batch testing in groups up to 10, using their own swabs, does work with PCR testing.

But the rapid test kits are designed to test just one sample from one swab, and there isn’t any data to determine how reliable any results actually are when taken from the off-label "pool" testing.

A study by E25 Bio tried to answer that question and found its rapid test kit could detect a positive, symptomatic sample among 19 negative samples.

Bobby Brooke Herrera, the chief science officer at E25Bio, told the outlet that families shouldn’t "go rogue" and stick multiple swabs into a vial with buffer solution measured for just one.

“By the time you put the fourth swab in the buffer, you’re probably going to have no buffer left,” he said.

Read the full piece, Families Are Going Rogue With Rapid Tests, at The Atlantic.