The U.S. Centers for Disease Control and Prevention (CDC) is only recommending people with symptoms be tested for the highly pathogenic avian influenza, or bird flu, because of concerns those without symptoms could test positive but would not be able to transmit the flu, an official said on June 13.
“We have ample amount and supply of testing, but ... if by testing somebody you’re happening just to pick up a stray amount of virus from their nasal passage but not actually detecting someone who’s clinically ill, who requires medication—who can pass it on to somebody else—then we’ve got to really kind of evaluate what we’re doing or accomplishing by that testing,” Dr. Nirav Shah, the CDC’s deputy director, told reporters on a call.
“To date, the data that we’ve seen suggests that testing gives us actionable data when it is not just someone who’s been exposed but rather someone who’s exposed but symptomatic,” he added.
The CDC remains open to changing its advice, officials said.
Bird flu, around for decades, only jumped to cows in recent months. The strain that hit cows, H5N1, has also sickened three people in the United States.
Two of those three patients suffered inflamed eyes. The third and most recent case also suffered respiratory symptoms.
More than 500 people have been monitored from the new H5N1 outbreak and at least 45 people have been tested, according to the CDC. Those numbers are expected to be updated on Friday.
During the COVID-19 pandemic, federal authorities like the CDC repeatedly advised testing both symptomatic and asymptomatic people as a way to identify cases and stem the spread of the virus. Officials have pointed to studies indicating some of the spread of COVID-19 was from asymptomatic people. People who tested positive for COVID-19 were for years told to isolate for days or even more than a week, without mention of how testing might only be picking up stray virus.
The CDC has been working with farms to do a sampling of asymptomatic workers, and the results might inform updates on H5N1 testing, Dr. Shah said. Officials want to “really make sure that our recommendations for testing are as science-based as possible,” he said.
The official also said the CDC has told states that the threshold for testing people is “exceedingly low.” If individuals who are exposed want to be tested, then they can be, “because we don’t have a constraint on the number of tests that we can do,” he added.
