Anal Swab Tests Being Used in China

China Using Anal Swab Tests
A medical worker collects a throat swab from a child in Beijing. Source: Getty Images

With the approach of the Lunar New Year, China is adopting an inconvenient method for detecting the novel coronavirus – anal swab test.

China is currently battling its worst wave of COVID-19 infections since July of last year. As a result, the country of almost 1.4 billion is not only conducting mass testing but also implementing extreme lockdown measures. These strict measures are a result of recent outbreaks in multiple cities in northern China. Moreover, with the advent of the Lunar New Year, the country is adopting new strategies to control the spread of infection. However, one particular tactic has raised quite a few eyebrows: the anal swab tests.

Last week, a single asymptomatic case in a school in Beijing led to 1,000 schoolchildren and teachers undergoing anal, throat and nose swabs. Along with antibody testing. Later on, a man in northern Shaanxi province tested negative on a throat swab, despite showing symptoms. It was only after conducting nose and anal swabs that the man tested positive. Local authorities hope that anal swab tests will help detect infections and reduce missed diagnosis.

If we add anal swab testing, it can raise our rate of identifying infected patients. But of course, considering that collecting anal swabs is not as convenient as throat swabs, at the moment only key groups such as those in quarantine receive both.

Li Tongzeng, infectious-disease specialist at Beijing You’an Hospital

What Does the Research Say?

As the name implies, anal swab tests are taken from the anus. A saline-soaked cotton swab is inserted 3 to 5 centimeters into the anus and gently rotated. The sample is then tested for traces of the virus.

The controversial new test has divided doctors regarding its accuracy. Li Tongzeng believes the virus can survive longer in the anus as compared to the respiratory tract. Thus, making it more accurate than oral and nasal swabs. Moreover, research has shown that stool tests are more effective than respiratory tests for detecting COVID-19 in children and infants.

There have been cases concerning the coronavirus testing positive in a patient’s excrement, but no evidence has suggested it had been transmitted through one’s digestive system.

Yang Zhanqiu, a deputy director of the pathogen biology department at Wuhan University

However, there is currently no evidence whether those who test positive with anal swabs are capable of transmitting the virus. Due to its unconventionality, the technique is currently only being conducted on those in quarantine. And those at high risk of contracting the disease.

China plans to vaccinate 50 million people by the start of the Lunar New Year, that is mid-February. Moreover, travelers arriving in Beijing are required to undergo serum antibody tests. With a combination of vaccination drives, anal swab tests, and serum antibody tests; China hopes to curb the rising number of infections in the country.

I am appealing to the public that people should try their best not to travel during the holiday. If they have to … please consider off-peak travel, and pay attention to personal hygiene during the trip, and try to avoid crowded places.

Zijian Feng, deputy director of the Chinese Centre for Disease Control and Prevention


Fan Q, Pan Y, Wu Q, Liu S, Song X, et al. 2020. Anal swab findings in an infant with COVID‐19. Pediatric Investigation, 4 (1),


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