Covid 19 coronavirus: China denies subjecting US diplomats to anal tests

China has denied subjecting US diplomats to Covid-19 anal tests following reports from Washington that some of its personnel were being made to undergo the procedure.

Chinese Foreign Ministry spokesperson Zhao Lijian told reporters at a daily briefing: "China has never asked US diplomats in China to go through anal swab tests."

A US State Department spokesperson said Washington was "committed to guaranteeing the safety and security of American diplomats and their families while preserving their dignity, consistent with the Vienna Convention on Diplomatic Relations as well as other relevant diplomatic law provisions".

The Washington Post reported last week that some US personnel had told the department they had been subjected to the anal tests.

The procedure has been applied in China because it is reportedly more accurate than nasal or mouth swabs.

China has not reported a new local case of Covid-19 in more than a week, but has maintained strict testing, especially for people arriving from abroad. Diplomats and other foreigners with special status are exempted from a ban on most foreigners entering the country.

Anal swabs have been used in China to test for Covid-19 since last year, but the method is mainly used in key groups at quarantine centres because of its inconvenience, according to a Chinese disease control expert.

To collect the nucleic acid samples, the swab needs to be inserted about three to five centimetres and rotated several times. Photo / Supplied

Speaking to state broadcaster CCTV, Li Tongzeng from Beijing You'an Hospital said that traces of the virus linger longer in the anus or excrement than those samples taken from throat and nasal swabs.

"We found that some asymptomatic patients tend to recover quickly. It's possible that there will be no trace of the virus in their throat after three to five days," Li noted.

"But the virus lasts longer from the samples taken from the patient's digestive tract and excrement, compared to the ones taken from the respiratory tract.

"If we conduct anal swabs for nucleic acid testing, it would increase the detection rates of patients and lower the chance of a missed diagnosis," the expert claimed.

- AP, additional reporting from NZ Herald