The nasal test—antigen, PCR, or self-test—has become routine for spotting COVID-19. Vaccinated or not, many in France test daily to check for infection. But are they reliable enough for "stealth" variants like Omicron?
When contacts test positive, we head to the pharmacy for an antigen test. In China, however, anal swabs are favored under the "zero COVID" policy. After spotting a potential Omicron cluster in Beijing, authorities tested 27 residents from the infected woman's building. These swabs are highly accurate, especially for asymptomatic or mild cases where the virus lingers in the gut.
Dr. Li Tongzeng of Beijing's You'an Hospital notes: "After three to five days, asymptomatic people may clear the virus from their throat. In some patients, it survives longer in the digestive tract or feces than the respiratory tract."
China increasingly uses anal swabs, even for inbound travelers. Yet foreign governments resist, sticking with nasal tests for now.
