Covid: China enforces anal swab testing ahead of Lunar New Year rush

China has begun carrying out strict coronavirus testing requirements in anticipation of the Lunar New Year holiday, as it grapples with a new surge in infections.

The festive season is the busiest time of the year in China and health authorities in Beijing said they were aiming to screen more than two million people in 48 hours using antibody tests and throat, nasal and anal swab tests.

According to reports, more than a million residents in Beijing have already undergone anal swabs as part of the screening. An infectious disease specialist, Li Tongzeng, from the You’an Hospital, told state broadcaster CCTV that anal swabs are more accurate and “reduce the return of false positives”.

He was quoted as saying: “In some asymptomatic cases or in individuals with mild symptoms, they tend to recover from the illness very quickly. It’s possible that there will be no trace of the virus in their throat after three to five days.

“What we’ve found is that in some infected patients, the coronavirus survives for a longer period of time in their digestive tract or excrement than in their respiratory tract.

“Of course, anal swabs aren’t as convenient as throat swabs, so they’re only being used on individuals in key quarantine areas. This will reduce the return of false positives,” he added.

However, the use of anal swabs in Covid testing has sparked some controversy among experts. Yang Zhanqiu, a deputy director of the pathogen biology department at Wuhan University, told state-run newspaper Global Times that the virus is a respiratory disease, therefore making nasal and throat swabs more efficient methods of testing.

He said that while there have been cases in which a person’s excrement has tested positive for coronavirus, there was no evidence to suggest the virus could be transmitted through one’s digestive system.

Last week, Beijing announced it would conduct antibody tests on all travellers arriving in the capital from overseas since 10 December as part of rigorous contact tracing for the latest cluster of infections found in the Daxing district.

Foreign arrivals are also facing up to 28 days of quarantine in a few Chinese cities. Beijing authorities announced a “14+7+7” quarantine system which involves 14 days of hotel quarantine, seven days of home quarantine and seven days of health monitoring, which means they are not allowed to join group activities.

Dalian and Nanjing cities have also introduced similar measures, as well as the provinces of Heilongjiang, Jilin and Zhejiang.

China’s National Health Commission also announced in a notice posted online that people returning to rural areas from other provinces over the Lunar New Year period would have to produce a negative Covid-19 test taken within seven days.

The aggressive new infection control measures come after a nine-year-old boy tested positive for the UK variant of coronavirus that is more transmissible and potentially more deadly than the original strain.

On Wednesday, China recorded its lowest daily increase in Covid-19 cases in more than two weeks with 75 new cases reported on 26 January. This is down from 82 new cases a day earlier and is the lowest single-day rise since 11 January.

The total number of confirmed coronavirus cases in mainland China now stands at 88,701, with the death toll remaining unchanged at 4,635.