Is CDC right to change testing guidelines?27 Aug 2020 18:04
The U-turn by the US Centres for Disease Control and Prevention on Covid-19 testing guidelines has raised eyebrows in the scientific community.
The agency no longer recommends testing for most people without symptoms, even if they have been in close contact with an infected person. Previously it said tests were appropriate for anybody who had reason to believe they had been exposed.
Experts warn that extensive testing is vital to contract tracing efforts, and controlling the spread of the virus. Some studies suggest that about half of all transmission is from people who have yet to develop symptoms.
However, the new guidance is no different to that in place in the UK. Under the NHS test and trace scheme, people who have been in contact with an infected person are advised to self-isolate for 14 days. A test is only deemed necessary if they develop symptoms. The rationale is that a single test will not definitely prove you are clear of the virus if you are in the early stages of infection, so it is better to wait until there is hard evidence that you are falling ill. Health Secretary Matt Han**** has suggested asymptomatic people may be tested later in the year if new rapid turn-around tests come on stream.