Scientists and researchers have confirmed the effectiveness of the anal swab in detecting COVID-19, despite the growing criticism.

The anal swab has become mandatory for all international arrivals to China, according to The Times newspaper.

A report by the 'The Mirror' indicated that the anal swab tests, which were used widely in areas of China that suffered from severe outbreaks of the coronavirus, are now used in airports in Beijing and Shanghai, after scientists confirmed their efficacy and accuracy in comparison to the other types of examinations.

According to an infectious diseases Doctor, Li Tongzeng, "the effects of the virus in anal swabs and stool samples can remain detectable for a longer period than samples taken from the upper respiratory tract." He indicated that rectal smaples are necessary, especially for those in quarantine.

Additionally, the Chief Doctor of Yuan Hospital in Beijing indicated that rectal swabs "could increase the rate of detection of those infected with the coronavirus."

In turn, researchers at the Hong Kong Chinese University said that the swab tests may be more effective in identifying COVID-19 in children.

- Protest and anger -

Countries protested China's adoption of the anal swab test, as Tokyo demanded Beijing to reverse this measure, which it said would cause great psychological distress for citizens.

Allegedly, US diplomats were subjected to an anal swab, which Beijing later denied. In February however, the Chinese government denied that it had “forced” US diplomats on its soil to take an anal swab test.

A Chinese Foreign Ministry spokesman, Zhao Lijian, responded to US media reports that had reported the aforementioned claims, stating that no such tests have been conducted to the best of his knowledge.

He stressed that "China is committed to ensuring the safety and security of US diplomats and their families, while preserving their dignity."

- Questioning effectiveness -

Researchers questioned the accuracy of this type of test to detect coronavirus infections, with US health experts from 'Healthline' claiming that these swabs are inaccurate.

An Associate Clinical Professor and Director of Clinical Microbiology in the UCLA Health System Omai Garner, indicated that the reports on this swab are incorrect, pointing out that he was surprised by the existence of such swabs to detect the coronavirus.

He stressed that it is well established that the most accurate sample is taken from the upper respiratory system, adding that scientists had already dismissed the consideration of adopting anal swab tests or stool examinations during the first months of the pandemic.

He pointed out that positive PCR tests in feces does not constitute to the presence of a live virus.