SEATAC, Wash. (AP) -- An Alaska Airline passenger sparked a health scare after vomiting blood, splashing seven passengers and telling crew members he might be infected with hepatitis C.

The passenger, who was not identified, was taken to Harborview Medical Center in Seattle after the incident Wednesday, Seattle-Tacoma International Airport spokesman Bob Parker said. His condition was not immediately known.

The affected passengers aboard Flight 553 from San Diego declined medical treatment, airline spokesman Lou Cancelmi said.

''They were calm about it. They were concerned about the individual,'' he said.

An estimated 2.7 million Americans carry the hepatitis C virus, a blood-borne infection that can lead to chronic liver problems, including cirrhosis and cancer.

Airport emergency medical technicians met the Boeing 737 when it landed and a biohazard crew immediately began cleaning the plane.

Passengers were detained for about 20 minutes as the situation was assessed. The flight carried 121 passengers and a crew of five.