Airlines, hotels and cruise operators serving Latin America and the Caribbean are facing growing concern among travelers spooked by the mosquito-borne Zika virus.
The outbreak of the virus, linked to brain damage in thousands of babies in Brazil, comes as a record percentage of Americans plan a vacation in coming months and a near-record proportion of them look to take advantage of a strong US dollar by going abroad.
The Centers for Disease Control and Prevention warned travelers via Twitter to consider postponing travel to areas with ongoing Zika transmission.
Canada and Chile are the only countries in the Americas the virus is not expected to reach, the World Health Organisation (WHO) said.
United Airlines said it was allowing customers who had reserved tickets for travel to Zika-impacted regions to postpone their trips or obtain refunds with no penalty.
Norwegian Cruise Line Holdings Ltd and rival Carnival Corp said they would allow expectant mothers covered by the CDC advisories to reschedule cruises to a later date or switch to an itinerary outside the affected countries.
But some Twitter users lamented their inability to get a refund from tourism operators.
Still, many airlines and tourist authorities said they have seen minimal impact.
A Carnival spokesman said there had been less than 10 requests to reschedule trips or change itineraries. A Norwegian spokeswoman said it had a single cancellation and no itinerary change requests.
Hotel chain Hilton Worldwide Holdings Inc said in a statement it was working closely with local health authorities throughout the region to follow CDC prevention recommendations.
Still, some tourists with short-term travel plans to Latin America were having second thoughts.
"It's the people who are going to travel in the next few weeks who are starting to ask more questions and rethink their plans," said Jennifer Michels, a spokeswoman for the American Society of Travel Agents, in Alexandria, Virginia.
Data released from the US Conference Board as part of its monthly Consumer Confidence Index showed a record 54.4 percent of Americans plan a vacation in the next six months.
Some 11.2 per cent said they plan to travel overseas, one of the highest readings in the survey's history dating back to 1978.
Airports stepping up efforts
Airports are stepping up efforts to reduce populations of mosquitoes that transmit the Zika virus in order to prevent its spread, the UN aviation agency said Thursday.
"The management of the outbreak is currently focused on reducing the populations of the Aedes mosquito that transmit the virus at airports (vector control)," the International Civil Aviation Organisation (ICAO) said in a statement.
Vector control refers to the spraying of insecticides or other pest control measures.
The Montreal-based agency urged airlines and airport authorities to follow World Health Organization guidelines on the testing and use of insecticides for aircraft, including new guidance specifically related to the Zika virus.
Meanwhile, "aviation stakeholders will continue to share information and resources in order to assist with controlling the outbreak," it added, saying it was working closely with the WHO and the US Centers for Disease Control and Prevention.
In most cases, Zika causes mild flu-like symptoms including fever, headache and body aches. But it has been linked to a rapid rise in the number of children born with microcephaly -- abnormally small heads and brains -- to mothers infected during pregnancy.
There is currently no cure or vaccine for Zika.
Confirmed cases have been found in 26 countries, spanning 7,000km (4,400 miles) from Mexico to Paraguay, according to the Pan American Health Organisation.
Brazil has been most affected by the outbreak, with 1.5 million people infected since early 2015, followed by Colombia.
Travelers have also brought infections as far north as Canada, and overseas. China confirmed its first imported case of Zika last month.