The CDC states that the risk of transmitting the Mpox virus in the cabin of a commercial aircraft is low

According to an investigation by the Centers for Disease Control and Prevention (CDC) published in the journal “From July 2021 to August 2022, the risk of in-flight transmission of mpox was considered low and does not justify routine contact tracing.” Weekly Morbidity and Mortality Report.

After receiving reports of travelers on commercial flights with probable or confirmed smallpox during the infectious period, CDC initiated an investigation into aircraft exposure in 2021-2022. Data was collected when in the United States and for flights arriving or traveling within the United States between April 30 and August 2, 2022 following global clade II mpox epidemic detected in May 2022.

Airline passengers occupying seats within 1 seat in any direction of a potentially infectious person for flights lasting 3 hours or less, or within 2 seats in any direction for flights longer than 3 hours, were considered to be in the risk of exposure zone. For 2 flights in July 2021, the exposure risk zone also included all passengers who potentially used the same bathroom as a potentially infectious person.

Crew members serving the cabin where the infected passengers were seated were considered contact persons. Crew members who worked on the same flights for a total of more than 3 hours as the infected crew members were also considered exposed.

In 2021, performance information was available for all 149 contact aircraft (passengers, n=138; crew members, n=11) from 30 national health departments. No secondary cases of mpox were reported.

In 2022, a total of 111 people were identified with probable or confirmed stage II smallpox. Of the 1,389 contacts identified, CDC received summary outcome information from 30 U.S. health departments for 897 (65%; passengers, n = 884; crew members, n = 13) contacts who took 218 flights between April 30 and April 2 August. No contacts developed mpox during symptom monitoring.

CDC notified IHR national contact points in 41 countries of 299 international travelers, 84 of whom had MNOX and 215 were exposed to infected persons mpoks on flights. Of the 21 IHR national focal points that provided data to CDC on contact tracing results, 1 reported that the contact developed symptoms within the 21-day monitoring period and was diagnosed with MNOX.

Limitations of the study include missing outcome data and the narrow definition used for aircraft contacts.

“CDC continues to recommend that people with mpox self-isolate and delay travel until they are no longer infectious,” the researchers concluded.