"An abrupt shift this week in government testing guidelines for Americans exposed to the novel coronavirus was directed by the White House’s coronavirus task force, alarming outside public health experts who warn the change could hasten the disease’s spread.
The new guidance — introduced this week, without any announcement, on the Centers for Disease Control and Prevention website — replaces advice that everyone who has been in close contact with an infected person should get tested to find out whether they had contracted the virus. Instead, the guidance says those without symptoms “do not necessarily need a test.”
Several leading infectious-disease experts predicted that, after months of public health exhortations encouraging people to get tested, the turnaround could heighten public confusion, impede contact tracing and lead to more cases. The CDC estimates that 40 percent of those who test positive for the coronavirus have no symptoms but may be highly infectious and spread it to other people."