A recent study by Danish scientists found that three out of four Chinese test kits had a 90% accuracy rate in detecting Covid-19.

In their findings, which were published on the preprint website Medrxiv.org on April 10, meaning they have yet to be peer-reviewed, the researchers said that the study was based on samples taken from people infected with the coronavirus who had been admitted to the intensive care unit at North Zealand Hospital in Hillerod.

The three Chinese subjects – an antibody test known as an enzyme-linked immunosorbent assay and two point-of-care tests – also had a 100% accuracy rate in detecting patients who did not have the Covid-19 virus, the report said.

“Accurate diagnosis of Covid-19 is essential not only to ensure appropriate patient care but also to facilitate identification of SARS-CoV-2 infected people, including asymptomatic carriers, who need to be isolated to limit virus spread,” the report said.

A Danish study returned positive results for Chinese manufacturers of Covid-19 test kits. (Picture: AFP)

The fourth Chinese test kit in the study was eliminated from the full test process after performing badly (along with one of the American subjects) in an initial round of testing, it said.

The study, which also looked at kits made in the United States, Germany and Canada, is yet to be verified by the wider scientific community. However, the results of the Danish study will doubtless come as a relief to Chinese test kit manufacturers after a succession of allegations about poor product quality.

Last month, a Spanish research institute found Covid-19 rapid test kits made by a Chinese biotech company had an accuracy rate of just 30%. The manufacturer replaced the consignment but denied the kits were substandard.

Turkey and the Czech Republic also complained of being sold substandard products, as did the Philippines, though the health department in Manila later apologized for doing so.

Meanwhile, a British study led by Derrick Crook, a microbiology professor at John Radcliffe Hospital in Oxford, said that while enzyme-linked immunosorbent assays were highly effective at detecting the antibody known as immunoglobulin G – which helps in diagnosing Covid-19 – commercially available test kits were not always accurate.

The researchers looked at nine different test kits and found them to have an accuracy rate of just 55% to 70%.