A medical staff member takes a nasal swab from a visitor (right) to test for the Covid-19 coronavirus at a virus testing centre in Seoul on February 9, 2022. ( AFP / Jung Yeon-je)

Korean posts share misleading advice on using Covid self-test kits

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Korean-language Facebook posts have repeatedly shared a graphic advising users of Covid-19 self-test kits to swab from the back of the throat to guarantee accurate results. However, health experts told AFP only trained professionals should collect swab samples from the back of the throat to avoid injury. South Korea's health officials advise that swabbing from just inside the nostrils is sufficient for self-test kits.

The graphic -- showing the anatomy of the nose and throat -- was shared here on Facebook on March 16, 2022.

Korean-language text superimposed on the image translates in part as: "How to use a self-test kit. How to guarantee 99% accuracy with the test. You must take samples from the oropharynx. The common way of using it is to take samples from 1.5 to 2 cm inside the nostril, but the accuracy is not that great."

The oropharynx refers to the part of the throat at the back of the mouth.

A screenshot of the misleading Facebook post, taken on March 30, 2022.

The post circulated in South Korea as the country battled record daily Covid-19 cases fuelled by the Omicron variant.

Demand for self-test kits surged, leading to shortages and price hikes, The Korea Herald newspaper reported.

Facebook posts featuring the same graphic were also published here, here and here.

However, the advice given in the graphic is misleading.

Health experts at Meedan, a global nonprofit that supports journalists in covering the pandemic, told AFP that swab samples from the back of the throat should only be taken by trained professionals to avoid injury.

They said this could include "piercing the back of the throat when pushed too hard, gagging, or swabbing in incorrect locations."

"The swab shouldn't punch the tongue, cheeks, gums, or teeth, which can be difficult for patients to see on their own," the experts added.

This information sheet published by the US Food and Drug Administration similarly states swab samples from the oropharynx should only be obtained by trained healthcare providers.

'Just inside the nostrils'

In guidance released on February 24, 2022, South Korea's Ministry of Food and Drug Safety said that "swab samples should be taken from 1.5 to 2 cm inside of the nostril" for self-test kits.

The World Health Organization has said rapid tests that people can use at home are generally less accurate than reverse transcription polymerase chain reaction (RT-PCR) tests, which it describes as the "gold standard".

But self-testing at home is useful when there is a surge in demand for testing or where delays in delivering results are mounting, the agency said.