In January, the United Nations World Tourism Organization projected that travel to Europe would increase between 3.5 and 4.5 percent this year. And, so far, its projection has been right on target: Tourism to Europe was up 4 percent through April.

But it wasn’t up everywhere, due to a spate of terrorist attacks on the continent that has altered tourists’ traditional itineraries.

France, for example, is still the top destination for American tourists, but it had a 10 percent drop in overnight stays through July in the wake of terrorist attacks in Paris in November and in Nice last month, The Independent reported.

And “summer travel to Brussels and Istanbul has fallen off a cliff,” Daniel Durazo of Allianz Global Assistance USA told CNBC.

Nevertheless, says Katelyn O’Shaughnessy, founder and CEO of the mobile app TripScope, fewer than 0.5 percent of the app’s users — mostly family travelers — have changed their itineraries or canceled their trips to Europe.

She said TripScope, which facilitates travel agents’ interactions with clients, has seen a slight uptick in European travel — about 53 percent of its itineraries are on the continent — but customers have been changing their destinations.

Instead of going to Turkey, she said, many Americans are opting to visit Italy and Spain, which have a similar climate but are considered safer. “Turkey is seen just as a conflict area,” O’Shaughnessy said.

Other industry insiders say they, too, have noticed a shift in destinations, not a decline in travel:

Jack Ezon, president of Ovation Vacations, a luxury leisure travel advisory, said his company’s bookings in France and London are down by 48 and 26 percent, but “68 percent of the business in Europe is shifting to perceived ‘safe’ countries like Italy, Greece and Spain.”

And Charles Neville, marketing manager for JayWay Travel, a boutique tour operator that focuses on Central and Eastern Europe, said, “We have plenty of staff based in Europe, and they are not noticing any reduction in visitor numbers in the cities they live in, either. And as a company we’re selling more trips this year than last.”

StudentUniverse, a travel booking service for students and youth, reported that “students booking study abroad trips to Europe (to depart in late August/early September) are up 29 percent” compared to last year — and London and Paris are still the most popular destinations.

O’Shaughnessy said TripScope users understand that one attack doesn’t make a destination unsafe, and they love the strength of the U.S. dollar compared to the euro and British pound. “Potentially you’re getting everything half off because the dollar is so strong,” she said.

So while a few Americans are crossing Europe off their itineraries this year, others see 2016 as a great time to visit.

“Travel is highly personal,” said Kurt Stahura, dean of the College of Hospitality & Tourism Management at Niagara University. “For example, many parents will allow their children to venture onto a bus or subway at the age of 11 or 12, but many wouldn’t dream of it.

“It’s the same with travel beyond our immediate areas. Some people will be put off by the threat of terrorism. Others will travel, with some degree of apprehension. Some may not factor it into their decision at all.”

Kristin Luna, a Nashville-based journalist and digital-media consultant,  is traveling to Europe this month, but she retooled her plans in order to avoid Turkey, which has seen several suicide bombings, including two in popular areas of Istanbul. Almost a year ago, Luna booked a river cruise from Budapest to Bucharest. Her group of eight would fly into and out of Istanbul, and she and her husband would spend six days there after their cruise.

But after the suicide bombings, Luna said, “We kind of grew a little concerned as the situation over there escalated.”

And “we’re not travelers who usually succumb to fear,” she said, noting that she and her husband honeymooned in Borneo when it was having a problem with pirates and kidnappers. But when terrorists killed 42 and injured 238 in Istanbul’s Ataturk Airport in June, she started looking at alternatives.

“We started to think, oh, well, maybe we should consider changing our plans. Who knows what’s going to happen there? Who knows if we’re going to be able to get to our river cruise or not?”

Luna said Turkish Airlines and Expedia, the website on which she booked her trip, refused to help her arrange alternative flights. “In the end,” she said, “we just yesterday booked all new flights and are going to eat the cost of those old flights.”

The cost of those round-trip tickets for eight: $8,500. Now, instead of spending time in Istanbul after their river cruise, she and her husband will travel through Romania and Austria.