Photo:Xinhua

Chinese coronavirus test kit manufacturer Guangzhou Wondfo Biotech Co said on Wednesday that it had not yet received feedback from the UK health department about its products, but its exports comply with the regulations of China and the EU. 

The company's comment followed UK media reports on the quality of test kits from China.

Experts said that inaccurate results may reflect testing methods rather than the technology itself, as similar manufacturing techniques are used by Chinese companies and their foreign counterparts.

The Daily Mail reported on Monday that the test kits the UK government ordered from China were not sufficiently accurate for public use, citing Oxford University professor John Bell, a scientist evaluating coronavirus antibody tests for the government. 

"We see many false negatives… and we also see false positives. This is not a good result for test suppliers or for us," the professor said, according to the newspaper.

The report claimed that the UK government would seek refunds from companies that could not improve the tests.

The UK bought 2 million coronavirus antibody tests from two Chinese manufacturers — Hangzhou AllTest Biotech Co and Wondfo — according to the Daily Mail. The latter said on Wednesday that the first batch of 500,000 antibody test kits arrived in the UK on April 2 and April 5 (UK time), and the kits are waiting to be tested for accuracy and specificity by the UK health department.

"The instructions for use included with the test make it clear that the test kit is for rapid, qualitative detection of SARS-CoV-2 IgG/IgM antibody. The test is to be used as an aid in the diagnosis of COVID-19," the company said.

"The test provides preliminary test results. It cannot be used as the sole basis for treatment or other management decision. This antibody test should be used within medical institutions and it is for professional use only," it added.

As COVID-19 rages in the UK, the country is urgently seeking a way to determine how many people have recovered from the virus and are immune. However, given the wide range of antibody responses to the new coronavirus, it is a challenge to make a simple, reliable test that works for everyone, the Guardian reported on Sunday.

A respiratory disease expert told the Global Times that an antibody test result has much to do with the time at which the sample is taken, as antibodies can only be detected some time after an individual has recovered from the virus.

"If it's a test for IgM antibodies, the result may come faster, whereas it could take seven to 10 days before a result is seen when testing for IgG antibodies," the expert said, noting that tests can be inaccurate if antibody levels are low.

According to the Daily Mail's report, Public Health England has not revealed what the UK government considers an acceptable level of accuracy.

Yang Zhanqiu, a virologist at Wuhan University, told the Global Times there is little possibility that test kit manufacturers' technologies led to "inaccuracy" as the Chinese manufacturing techniques are similar to those of foreign enterprises. "Many Chinese producers use imported equipment for manufacturing," he said.

Being one of the first enterprises to develop coronavirus test kits in China, Wondfo has been exporting its antibody test kits since receiving approval to do so in China and the EU, the company said, noting that its exports comply with the new regulations from the Ministry of Commerce, the General Administration of Customs and the National Medical Products Administration (NMPA).

To ensure the quality of exported supplies, China on April 1 started to require all medical products to obtain a certificate from Chinese regulators before the items could be exported, according to a statement released by the NMPA.