Agency officials believe nearly 11,000 people may have been exposed to one of the 1,600 known cases of people flying while contagious with the virus — despite being unable to confirm a single case of viral transmission on a US plane.
“An absence of cases identified or reported is not evidence that there were no cases,” CDC spokeswoman Caitlin Shockey told the Washington Post, which first reported the stats.
“CDC is not able to definitively determine that potential cases were associated (or not) with exposure in the air cabin or through air travel given the numerous opportunities for potential exposure associated with the entire travel journey and widespread global distribution of the virus,” Shockey said.
Studies published by the CDC’s journal have also found evidence that COVID-19 may have spread on airplanes in other countries.
The most recent report, published on Friday, detailed a Vietnam Airlines passenger who likely spread the virus to 14 fellow travelers on a March 1 flight from London to Hanoi. The flight had 217 people aboard, researchers said.
US airlines typically now require all passengers to wear masks while on board.
The CDC’s own guidance says viruses do not spread as easily on flights “because of how air circulates and is filtered on airplanes,” but warns, “There may be a risk of getting COVID-19 on crowded flights if there are other travelers on board with COVID-19.”