The CDC’s covid-19 advice is wrong. If you’ve been exposed, you should be tested.

The CDC’s covid-19 advice is wrong. If you’ve been exposed, you should be tested.

Without explanation, and in contravention of common sense, federal officials have issued new guidance against testing asymptomatic individuals — specifically, those who have been exposed to someone diagnosed with covid-19. The recommendations, issued without fanfare on Mondayby the Centers for Disease Control and Prevention, pose a danger to public health, and contradict what we know about how to stem the spread of the pandemic.

The numbers tell the story. The CDC itself estimates that 40 percent of people with covid-19 don’t have symptoms. They are capable of spreading the disease, even if not quite as effectively as those with symptoms; again, according to the CDC, the chance that an asymptomatic individual will infect another person is 75 percent of that of someone with symptoms. Due largely to insufficient testing of asymptomatic individuals, CDC Director Robert Redfield has estimated that the number of people with covid-19 is as many as 10 times higher than the official count.

In other words, we should be testing more people without symptoms, not fewer.