Health Ministry: Covid-19 'rapid test kit' not recommended for early detection

[beijingwalker]

Health Ministry: Covid-19 'rapid test kit' not recommended for early detection
By Nor Ain Mohamed Radhi
March 24, 2020 @ 7:37pm

PUTRAJAYA: Health director-general Datuk Dr Noor Hisham Abdullah today cautioned that a 'rapid test kit' (RTK) being sold in the market could not help with the early detection of Covid-19.

He said this was because human antibodies only appear after five to eight days following the coronavirus infection.

“Hence, the test kit, which is currently available in the market to detect antibodies produced due to infection, cannot detect the virus or confirm infection quickly.

“Therefore, RTK is not recommended for the purpose of diagnosing Covid-19,” he said during a daily press conference on Covid-19.

He also urged member of the public not to take the RTK test without first consulting the medical practitioners, as it may cause misunderstanding and create worry over the outcome of the test.

Dr Noor Hisham said laboratory tests conducted at government health facilities for Covid-19 infection are using the Real-Time Reverse Transcription-Polymerase Chain Reaction (rRT-PCR) technique.

“The rRT-PCR test will detect the presence of the Covid-19 virus in the patient’s body.

“Therefore, a positive Covid-19 rRT-PCR test means that the individual has been infected with the Covid-19 virus.”

Dr Noor Hisham added that accurate test results through rRT-PCR techniques are crucial in the effective management of Covid-19 patients.

Yesterday, it was reported that a company was set to bring in a Covid-19 test kit for the Malaysian market, pending approval from the government.

The company claimed that the test kit has fulfilled regulatory requirements in the United States, clearing the way for the sale of the devices there.

The company said the test kits, developed by a reputable Chinese biomedical company, has qualified for emergency use authorisation granted by the US Food and Drug Administration (FDA) under a policy to accelerate detection and diagnosis during public health emergencies.

The test kit enables the early detection of the Covid-19 virus through the use of blood samples obtained from finger-pricking, specifically by detecting the presence of antibodies.
https://www.nst.com.my/news/nation/...apid-test-kit-not-recommended-early-detection

 

[beijingwalker]

‘10-minute diagnostic tests not recommended due to inaccuracy’

• By Song Soo-youn
• Published 2020.03.19 15:49

As the world is grappling with the new coronavirus pandemic, many have called for the introduction of rapid diagnostic tests (RDTs), which can produce results in around 10 minutes.

Healthcare experts, however, did not recommend using them due to inaccuracy, at a YouTube show Tuesday by K-Healthlog, a channel operated by The Korea Doctors’ Weekly.

RDT results come out quickly, compared to real-time polymerase chain reaction (PCR) tests now used in Korea, which take about six hours to screen out COVID-19 patients. However, RDTs have 50 to 70 percent of sensitivity, compared to PCR tests, meaning that a COVID-19 patient could test false-negative, or a healthy person could test false-positive. Such inaccuracy will add confusion, experts said.

Diagnostic testing for viral infections includes molecular diagnosis, cell culture, and antigen/antibody testing. RDTs use antigens or antibodies. Usually, it takes about two to four weeks for a human body to develop an antibody against infectious disease, antigen detection is used more for RDTs than antibody detection.

Lee Hyuk-min, director of infection control affairs at the Korean Society for Laboratory Medicine, said it was too early to introduce RDTs during a YouTube live show, K-Healthlog, hosted by The Korean Doctors’ Weekly, on Tuesday.

“Antibody testing can check the viral infection by targeting an antibody that develops after a virus gets into a human body. But the entry of a virus does not create an antibody right away,” Lee said. “So, we use antibody testing in the late-stage viral infection to look at epidemiologic linkage rather than in the early-stage infection.”

Antigen testing, often used in RDTs, is also inaccurate, compared to molecular diagnostics, he noted.

“Antigen testing amplifies a signal using various methods. So, their sensitivity is lower than the PCR tests. In clinical settings, the sensitivity of antigen testing for influenza infection is 50-70 percent of that of PCR tests,” Lee explained.

Antigen testing requires several conditions, and the most important condition would be persuading the public to tolerate inaccuracy of the test, Lee went on to say.

“If a diagnosis of flu goes wrong, a patient might get angry, but it won’t be a serious problem. But if COVID-19 testing gets wrong, it will be more than that,” Lee said.

On the condition that a treatment is available and quick diagnosis is necessary, antigen testing could help, he said. However, the nation has to mitigate the spread of COVID-19 as much as possible, so physicians are doing PCR tests, not antigen testing, he added.

Shin Hyun-young, a professor of family medicine at Myongji Hospital, said flu offers many other options for physicians because doctors could still prescribe Tamiflu at their discretion despite a wrong diagnosis.

‘Korea capable of 20,000 daily PCR tests, no need for RDTs’

In a joint statement, six diagnostics societies in Korea said, “It is very dangerous to introduce rapid diagnostic tests to detect COVID-19 during this global pandemic.”

RDTs using antigen or antibody can quickly yield results within about 10 minutes. Still, their accuracy is significantly low at 50-70 percent of that of molecular genetic tests, they said.

“Due to false results, an infected patient could freely move around without a diagnosis and transmit the virus to others, or a healthy person could be hospitalized for no reason, waste medical supplies, and become vulnerable to unnecessary infection risks, causing grave social confusion,” they said.

Korea has already established a system for massive molecular genetic tests, capable of conducting 15,000 to 25,000 PCR tests, and the accurate testing needs only about six hours, the statement said. “At this moment, Korea does not need to introduce RDTs.”

http://www.koreabiomed.com/news/articleView.html?idxno=7762

 

[beijingwalker]

"However, according to seznamzpravy.cz, doctors and hygienists were informed that this might happen. Indeed, the rapid tests that arrived from China a few days ago do not reliably detect the infection at an early stage.
According to a document of the National Institute of Public Health, rapid tests have only a “supporting role” in testing.

The institute explained that these tests cannot detect the virus in the first five to seven days after being infected as the person has yet to start producing coronavirus antibodies in the blood. The rapid tests are based on detecting these antibodies, though.

“The test is not a diagnostic test,” the National Institute of Public Health stated.

In other words, it is better to use these tests at the end of the 14- days quarantine period to confirm if the person suspected of having coronavirus is indeed infected.

Hygienists in Ostrava have already announced that they will introduce such a system, using the tests on people who were placed under preventive quarantine but not tested."

https://www.praguemorning.cz/80-of-...e-czech-republic-bought-from-china-are-wrong/

As suggested by the manufacturer, RTK are only for supporting and emergency use, not a standard way to diagnose patients. When do have too many patients but not much time, they help you catch at least some infected quick and fast.

 

[Mista]

I read that Singapore has just invented a test which can detect Covid-19 in 5 minutes, and the researchers are going to submit for approval in the next month.

https://mothership.sg/2020/03/covid-19-test-how-long/
https://www.straitstimes.com/singap...-on-the-front-lines-of-fight-against-covid-19