Several 
United Airlines
passengers traveling between Guam and Tokyo on Friday were confronted with an unwanted surprise after becoming ill during a flight to Tokyo. While the exact origins of the illness are still unknown, Japanese authorities have launched an investigation to determine the cause of the outbreak.
Trouble on flight 873
The events transpired on United flight 873, operating a regularly scheduled service between Guam’s Antonio B. Won Pat International Airport (GUM) and Narita Airport (NRT). One of United’s Boeing 737-800 aircraft (N37293) was operating the route.
Photo: Lukas Souza | Simple Flying
The flight left Guam 12 minutes late, 17:12 local time, and was scheduled to take 3 hours and 55 minutes. While on the flight, 18 passengers felt ill and displayed typical symptoms of food poisoning, primarily nausea and vomiting. Upon arrival in Tokyo at 19:29, some passengers were taken to the hospital for treatment, while others were able to leave without any additional care.
Parallel experience on Japan Airlines
The incident that transpired on United was not isolated—in fact, the exact same thing happened on a Japan Airlines (JAL) flight that departed just a few minutes earlier on the exact same route. JAL942 departed Guam at 16:41. The flight, which was operated by one of the carrier’s 767-300ERs, encountered similar disruptions when 16 passengers fell ill.
Photo: KITTIKUN YOKSAP | Shutterstock
While all passengers who got sick showed typical symptoms of food poisoning, JAL refuted claims that in-flight catering caused the sickness in a statement to the authorities. It pointed to the fact that some passengers were reported to show signs of illness before boarding the plane.
Since a similar incident happened on two separate flights operated by two carriers, authorities now suspect the sickness originated somewhere in Guam—not on either aircraft. While Japanese authorities have not confirmed anything, an investigation continues into what made a total of 34 passengers sick.
Similar incidents this year
Though it seems in-flight meals were not the source of Friday’s outbreak, several food-related health incidents have disrupted flights this past year. For example, a United Airlines flight traveling between Seoul, South Korea, and San Francisco, California, was forced to turn around after several crew members fell ill.
The incident occurred in May 2024, two hours into the aircraft’s 10-hour journey. The aircraft turned around and returned to Seoul. Despite never reaching North America, the aircraft spent four hours in the air. Crew members were likely sick from the food they ate prior to boarding.
Still, several incidents involving in-flight meals have plagued carriers this year. For example, an entire Detroit catering facility had to be temporarily closed after Delta passengers found black mold in a chicken dish on a flight from Detroit to Amsterdam this summer. The incident seemingly sparked a surprise audit of the catering provider, which ultimately failed.
Photo: Robert Buchel | Shutterstock
As a result, at least 200 flights operated by Delta and American Airlines had to operate without catering. United remained unaffected, as catering is supplied only from its hubs—enough food is provided for a return trip to a base where catering is provided.
While this recent event is unfortunate, both United and JAL were able to cooperate with local authorities quickly to ensure passengers in need of treatment were accounted for. The swift action taken by the involved parties is a testament to the safety of modern aviation.