Nasopharyngeal samples are the most common in France, whether for antigen tests or PCR. But their effectiveness against the Omicron variant is undermined compared to saliva tests.
According to American experts, nasopharyngeal tests would be more likely to present false negative results when faced with the Omicron variant. While in France antigen and PCR tests are exclusively done by passing a swab into the nostrils, the situation could perhaps change. Saliva tests, the use of which has been extended in France since February 2021 at the request of the Haute Autorité de Santé and which consists of spitting into a jar in order to analyze saliva, would better detect the Omicron variant if we believe it New York Times.
Saliva or nasopharyngeal test: what weapon against Omicron?
As reported by JDD, the American journal echoes a preliminary study published this week in the medical journal MedRxiv.
In the latter, we learn that “The reliability of the type of sample would vary depending on the variant: with Delta, the nasal test is 100% reliable compared to 71% with a saliva test. Conversely, with the Omicron variant, the saliva test is 100% reliable compared to 86% with a nasopharyngeal swab. »
Figures that could help countries better detect patients carrying the Omicron variant. The HAS says it is looking into this study and could give new instructions soon. On the waves of South Radio this morning, Gilles Bonnefond, pharmacist in Montélimar and spokesperson for the Syndicate Union of Community Pharmacists said he was mixed in the face of these results.
“It’s just a pre-study. There have been many studies on the Covid-19 and big disappointments (…) I am cautious about saliva tests. The sampling conditions are not obvious. The saliva must not be too thick, otherwise it will not work. The retention period must be short enough for the result to be achieved, “ said the pharmacist.