WHO no longer recommends widespread COVID-19 testing of asymptomatic cases

In updated guidance on COVID-19 screening strategies, the World Health Organization (WHO) states that it does not currently recommend widespread screening of asymptomatic individuals, citing the cost of such a strategy and its ineffectiveness.

“Widespread testing of asymptomatic populations, including through self-testing, is not currently recommended because of the lack of evidence on the impact and cost-effectiveness of such approaches and concern that this approach risks diverting resources from higher-priority testing indications,” it says in guidance.

However, “countries with the resources and desire to expand testing to the general public (regardless of symptoms) must demonstrate that they have the public health infrastructure in place to respond to positive results and that resources are not being taken away from testing of suspected cases, which are the highest priority,” WHO told The Epoch Times by email.

Testing should be targeted “where it is expected to have the greatest public health impact,” WHO said, adding that “this means that all persons suspected [as defined by WHO] of having COVID-19 on the basis of symptoms should be prioritized for testing,” regardless of their vaccination status or history of the disease.

But in areas with ongoing community transmission, anyone who has been in contact with a probable or confirmed case should be quarantined for 14 days, regardless of whether they are asymptomatic and have not been confirmed positive.

The headquarters of the Centers for Disease Control (CDC), in Atlanta, Georgia, on April 23, 2020. (Tami Chappell/Getty Images)
The Centers for Disease Control and Prevention (CDC) notes in its most current guidance that asymptomatic, unvaccinated individuals should be quarantined and tested if they were in close contact with a COVID-19-positive individual.

“Viral testing is recommended for unvaccinated individuals who are in close contact with persons with COVID-19,” CDC says. “These individuals should be tested immediately upon identification and, if negative, retested within 5-7 days of the last exposure or immediately if symptoms develop during quarantine.”

In contrast, fully vaccinated persons do not need to be quarantined, tested, “or have work restrictions” after close contact with persons with suspected or confirmed COVID-19 if they do not have COVID-like symptoms, “as their risk of infection is low,” according to the CDC. However, self-monitoring for COVID-19 symptoms is recommended for 14 days after exposure.

CDC says testing is still recommended for “fully vaccinated residents and employees of correctional and detention facilities and homeless shelters.”

Individuals are considered fully vaccinated two weeks after their second dose of a messenger RNA vaccine or a single dose of Johnson & Johnson vaccine.

WHO’s current guidance on prioritizing testing for people with symptoms is consistent with what had been its pre-pandemic guidance in the treatment and diagnosis of respiratory viral outbreaks-including the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak and the 2012 Middle East Respiratory Syndrome (MERS) outbreak-which was to focus predominantly on symptomatic cases to stop disease transmission.

Data have indicated that asymptomatic spread is not as frequent as previous studies claimed and that the risk of transmission from asymptomatic patients is low.

COVID cases can be confirmed by antigen testing
Throughout last year’s pandemic, the standard for diagnosing a CCP (Chinese Communist Party) virus infection was a PCR (polymerase chain reaction) test with cycle threshold values of 40 cycles or more. This raised concerns that there might be overconfidence and misuse of the test as a diagnostic tool, as it cannot differentiate between a live infectious virus and an inactivated virus fragment that is not infectious.

Persons who had a positive PCR test with or without COVID-19 symptoms were considered a case and were added to the daily COVID-19 case count.

The CCP virus causes COVID-19 disease.

WHO then updated its recommendations on the use of PCR testing on January 20, 2021, cautioning laboratory experts and users of in vitro diagnostic medical devices not to rely solely on PCR test results to diagnose COVID-19. Instead, along with the PCR test, the patient’s health history and epidemiological risk factors should also be considered for diagnosis.

Now, verification of a case of COVID-19 can be done by an antigen test, instead of a nucleic acid amplification test (NAAT) such as the widely used PCR test.

In the updated recommendation, WHO states that while “NAAT is considered a reference standard for the diagnosis of SARS-CoV-2 infection,” an antigen test can be used to diagnose a PCR infection “when NAAT is not available or when results are delayed by more than 48 hours.”

Three scenarios in which a nucleic acid amplification test is not required in addition to an antigen test result include:

In symptomatic individuals in high-prevalence settings, positive antigen test results do not need to be confirmed by NAAT, while a negative antigen test result “may be confirmed by NAAT at clinical discretion.”
In low prevalence settings, confirmation of negative antigen test results by NAAT is not necessary, whereas a positive antigen test result is clinically dependent for confirmation by NAAT.
In asymptomatic persons “who are contacts of confirmed cases or are frequently exposed, such as health care and long-term care workers,” confirmation of an antigen test result by NAAT is not necessary.
Antigen tests are immunoassays that can detect whether an individual has an active CCP virus infection in about 15 to 30 minutes and are less sensitive than a PCR test. According to WHO, antigen tests are “sensitive only for the detection of patients with a high viral load, e.g., cycle threshold (Ct) values [of approximately] 25-30.”

Source: The Epoch Times in English