Wait 3 days, then swab throat and nose when using antigen test, Health Ministry says

The Health Ministry published new recommendations on how to use the at-home kits, amid criticism for their lack of accuracy.

JANUARY 10, 2022 11:21

Updated: JANUARY 10, 2022 22:39

Meuhedet Health care worker wearing protective gear takes swab samples from a woman, at Meuhedet coronavirus testing center in Jerusalem, January 6, 2022. (photo credit: YONATAN SINDEL/FLASH90) — Meuhedet Health care worker wearing protective gear takes swab samples from a woman, at Meuhedet coronavirus testing center in Jerusalem, January 6, 2022.

(photo credit: YONATAN SINDEL/FLASH90)

The best way to use an at-home antigen test is to wait three days after being exposed to a verified case, read the instructions well and swab both the throat and the nose, the Health Ministry said Monday in a post circulated on social media.

Last week, Israel changed its testing policy, reserving PCRs – the most accurate type of tests, which need to be processed in a lab – to individuals over 60 and other at-risk groups. Since then, there has been a lot of criticism because antigen tests are less sensitive, and therefore people risk being misdiagnosed.

Earlier in the day, Dr. Sharon Alroy-Preis, head of the Health Ministry’s Public Health Service, made a similar recommendation in an interview with Army Radio.

“In order to increase their sensitivity, we will from now on recommend swabbing the throat and the nose,” she said. “It’s not what the manufacturer instructs, but we are instructing this.”

However, the recommendation goes against the advice of the US Food and Drug Administration, which has said manufacturers’ instructions should still be followed and that any incorrect use of throat swabs could pose a safety risk.

People pose with syringe with needle in front of displayed words ''OMICRON SARS-COV-2'' in this illustration taken, December 11, 2021 (credit: REUTERS/DADO RUVIC/ILLUSTRATION/FILE PHOTO)

During a press briefing, coronavirus commissioner Prof. Salman Zarka said they had checked the issue, and a similar policy was already applied in the UK. The ministry was also in contact with the manufacturers, he said.

Some infectious-disease experts have advocated throat swabbing with antigen tests because people can already transmit Omicron to others when it has infected their throat and saliva but before the virus reaches their nose.

A non-peer-reviewed study released on Wednesday on medRxiv.org 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 rapid nose-swab samples became positive.

However, the FDA tweeted on Friday, “When it comes to at-home rapid antigen COVID-19 tests, those swabs are for your nose and not your throat.”

FACT: When it comes to at-home rapid antigen #COVID19 tests, those swabs are for your nose and not your throat. https://t.co/WpgTKrGV4q pic.twitter.com/eyZHADezYB
— U.S. FDA (@US_FDA) January 7, 2022