You only have to look as far as Dallas/Fort Worth International Airport's Terminal D to see why airlines are already sick about the swine flu.
On Tuesday, more passengers wore surgical masks, talked about cutting trips short and considered canceling altogether.
Luis Fernando, who was headed home to Guadalajara, Mexico, wore a mask as he walked through the terminal. He said he wanted to extend his vacation in the United States to avoid flying, but had to get back to work.
"We had heard about this flu before, but not this close to home," Fernando said. "So, yeah, I'm a little bit afraid, yeah."
American Airlines has 42 daily flights from DFW to Mexico. The airline would not say what percentage of passengers have canceled their reservations, but an airline spokesman said Tuesday the number was not "huge or overwhelming."
For an industry that has weathered a fuel crisis and a global financial crisis in the last 18 months, swine flu is the last thing it needs.
Stock in American's parent company tumbled 13 percent Monday on fears that the influenza could trigger a drop in worldwide travel.
And while cancellations prompt jitters, the airlines are also worried about the health of their passengers and crew.
Over the weekend, a child on an American Airlines flight to DFW who was vomiting was tested for swine flu, according to an airline spokesman, Tim Smith. The test came back negative.
But flight attendants said Tuesday the airline was putting more masks and gloves on its planes for crews who might come in contact with sick passengers.