Coronavirus anal swab tests unreliable – State of the experts

The recent coronavirus outbreaks around the world have urged countries to take drastic measures to prevent further spread. As the UK re-imposed a full lockdown, China has found other ways to control transmission rates of the virus, including mass testing with anal swab testing.

Currently, China is experiencing its worst virus outbreak since it first began in Wuhan, with most of the new cases linked to international travel. Although standard testing is already underway, the use of anal swabs has been recommended by some experts in China to avoid false negatives.

There is some limited evidence that anal swabs may be useful in detecting the coronavirus to a similar extent to the virus in cases where its respiratory symptoms go away but the infection persists.

Additionally, the same study also concludes that people have active gastrointestinal infections while carrying the virus, even in the absence of infections. Therefore, in order to diagnose coronavirus, it is reliable to take swabs from the rectal opening.

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However, American experts do not share the same views. Not only are anal swabs not as reliable, they can be uncomfortable as they require the insertion of a two-inch swab which may also require rotating several times.

Since COVID-19 is primarily a respiratory infection, US experts say the nose and throat are better than the rest. It took a long time to find an accurate test for the virus.

At the start of the pandemic, the United States Centers for Disease Control and Prevention used several samples from people ranging from blood to stool to find the right accurate diagnostic method.

This is why many of the tests that were used in the spring of 2020 were not as reliable and gave a lot of false positives and negatives. After a full year, there is enough data and research to show that swabs from the mouth and nose are the best for diagnosing coronavirus infection.

Replacing the standard test for anal swabs may not be the best decision as there is a lack of research on this. On the other hand, there is ample evidence that supports the effectiveness of tests used in the United States and elsewhere in the world.

In China, the use of anal swabs is not very recent. The use of swabs along with stool screening has been used to diagnose coronavirus in the country since March of last year.

Initially, these two methods were only used in infants and children at high risk as well as in those living in areas where the number of cases was increasing.

Since both methods are non-invasive and easier to collect than sputum samples in some areas, they are useful in detecting the virus and preventing it from spreading further.

Through these two tests, six people in Hong Kong were also infected a week after recovering from their respiratory symptoms, as reported by CU Medicine.

Although experts in the United States do not support the complete elimination of anal swab testing, they do say the gold standard should be used especially when testing in adults.