WASHINGTON — News that a health worker diagnosed with Ebola flew on a commercial flight the night before showing symptoms raised fears on Wall Street that the scare over the virus could reduce air travel.

Shares of the biggest U.S. airlines tumbled between 4 percent and 6 percent in afternoon trading.

Frontier Airlines announced that public-health officials were notifying the 132 passengers on Monday night’s Flight 1143 from Cleveland to Dallas-Fort Worth. The airline’s crew reports that the woman showed no symptoms during the flight.

Frontier said health officials were seeking to interview passengers and monitor those deemed to be at risk for contracting the virus.

Shares of Republic Airways Holdings, which owns Frontier, sank more than 4 percent.

Since the first case of Ebola diagnosed in the U.S. last month, attention has focused mostly on travelers from West Africa, the center of the epidemic. The first victim was a Liberian man who flew into Dallas-Fort Worth International Airport on a United Airlines flight from Washington’s Dulles Airport. That case led U.S. officials to expand health screening of passengers from West Africa who arrive at five major airports.

RELATED: Obama Cancels Political Trips To Meet With Cabinet On Ebola Outbreak

The latest health worker flew on a domestic flight from an airport where there is no screening for fever.

Dallas-Fort Worth International Airport says it handles about 165,000 passengers per day or 60 million in a year. Airlines there operate both international and domestic flights.

Robert Mann, an aviation consultant and former American Airlines executive, said the latest raises new questions about the Dallas hospital that treated the Liberian man and employed the two health workers who contractedEbola after treating him.

Mann said that if the second worker showed no symptoms on her Frontier flight, the decision to notify other passengers was made out of extra caution. “But all that rational thought aside, it may cause some people to delay trips,” he said.

That possibility unnerved airline investors. Airlines with the biggest international networks sold off the most.

United Continental Holdings Inc. was down $2.78, or 6.4 percent, to $40.39; Delta Air Lines Inc. fell $1.51, or 4.6 percent, to $31.28; and American Airlines Group Inc. dropped $1.36, or 4.3 percent, to $30.15.

Republic Airways shares were down 47 cents, or 4.4 percent, to $10.20.

Airline stocks have slumped in recent weeks on Ebola fears and concern about slower growth in the global economy, which could offset the benefit to airlines from falling fuel prices.

(© Copyright 2014 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)