The swine flu outbreak may ring more than just alarm bells for public health officials. Depending on how widespread it gets, the flu could also mean another blow to Hawai'i's struggling economy.

While there are no reported cases of the flu here, there are worries its rise in other states and elsewhere in the Northern Hemisphere could lead to a damping of travel.

"We certainly don't need anything that is an additional excuse not to travel," said Leroy Laney, a Hawai'i Pacific University finance and economics professor.

"It doesn't come at a particularly good time."

Nationally, economists say the outbreak amplifies downside risks to the U.S. economy and slow economic activity. Yesterday Wall Street reflected those concerns, sending share prices of Hawaiian Holdings Inc. and other travel-related companies down on worries that people could postpone travel if the outbreak becomes widespread.

As of late yesterday the Centers for Disease Control and Prevention said the known cases in the U.S. haven't been as severe as those in Mexico, where the number of deaths suspected of being caused by swine flu rose to 149.

But the CDC also said the situation was evolving quickly and that it expected more U.S. cases, some of which could be more severe.

News of the outbreak in North America prompted the European Union to advise against nonessential travel to the United States and Mexico. Tourism officials worry that people could slow travel both to and within the U.S., including taking trips to Hawai'i.

The U.S. Travel Association was quick note people shouldn't be discouraged from visiting U.S. destinations.

"We recommend that government officials treat this issue and any forthcoming statements with care and caution," said Roger Dow, president of the U.S. Travel Association, in a press statement.

"We must address the situation with measured, pragmatic responses so as not to cause panic and negative consequences to the economy if health risks are not imminent."

Worse yet is a scenario in which the problem lingers for months and includes deaths in the U.S. Under those circumstances the U.S. economic recovery could be pushed well into 2010, Mark Zandi, chief economist at Moody's Economy.com, told the Associated Press.

"Consumer spending is already frayed and something like that would push it over the edge," Zandi said.

There are similar implications under this scenario for Hawai'i, which is seen as recovering as the Mainland economy recovers. A recent study found tourism accounts for 35 percent to 40 percent of Hawai'i's gross domestic product.

There's also, to be sure, another view that Hawai'i could reap visitors who are rebooking vacations from Mexico resorts in Cancun and Cozumel to the 50th state.

Hawai'i also has the advantage of not being one of the five states (New York, California, Texas, Kansas and Ohio) where confirmed outbreaks have been reported. The state also has experience in dealing with such downturns, having been through SARS (severe acute respiratory syndrome) in 2003 and then the threat of bird flu.

Hawai'i started to recover from SARS and the start of the Iraq war within a year.

But what happens with the current recovery could be different given the recession has been termed the deepest since statehood. Laney declined to speculate on what might happen should the swine flu outbreak become widespread in the U.S.

But at the least, the current situation is "certainly something we don't need right now with tourism in the condition it's in."

The Associated Press contributed to this report.