Erica Jackowitz is the type of traveler who will usually go anywhere. The 36-year-old Upper East Side resident not only co-owns her own luxury travel agency, Roman & Erica, she’s traveled to upward of 50 countries, honeymooning in Bhutan and sleeping in a tent in the Himalayas.

But Jackowitz recently did something unprecedented — she canceled an upcoming trip to Puerto Rico’s luxe St. Regis Bahia Beach Resort. The reason? She’s pregnant and afraid of the Zika virus.

“My doctor told me that under no circumstances should I travel to the region,” says Jackowitz, who just entered her second trimester and received a full refund from the airline. “Two other people in my group who are either pregnant or trying to conceive also canceled.”

On Monday, Zika was declared a public health emergency by the World Health Organization, and now New York parents, potential parents and physicians are scrambling to understand a disease that remains, at its core, an epidemiological enigma. An estimated 1.5 million Zika cases have been diagnosed just in Brazil — the world’s hardest-hit nation — with tens of thousands more globally.

Symptoms in sufferers are mild — just rashes, headaches, fevers and joint pain. The problem is that upward of 80 percent of those infected show no symptoms at all, leaving their unborn children at risk of microcephaly — the rare congenital defect linked to Zika infection in pregnant women. Doctors are still unsure whether the virus can linger in the bloodstream for weeks or far longer.

Like West Nile virus, Zika seems to spread when folks are bitten by a mosquito carrying the virus. Anecdotal evidence also suggests that Zika is transmitted sexually through infected semen. Over the weekend, Public Health England — Britain’s equivalent of the CDC — advised male travelers to use condoms for 28 days after returning from Zika-affected nations. And it’s a warning, say New York doctors, that US men should also consider — particularly if they’re planning to try for a baby.

Use condoms upon return, suggests Dr. Brian Levine, New York director for the Colorado Center for Reproductive Medicine. “And if you absolutely must travel, consider storing a semen sample at a lab before departure.”

Because of this uncertainty, fear has become palpable among New Yorkers — particularly the city’s upper crust — planning travel to Zika-laden areas.

Take Sybil Bunn, a publicist from Brooklyn Heights who had planned a “babymoon” in Cartagena, Colombia. “My husband and I wanted someplace warm, and Cartagena was a place we’d always dreamed about,” says the 29-year-old, who’s 22 weeks pregnant with her first child. But with 20,000-plus Zika cases in the country, her dream has turned into a nightmare.

“My mom was just like, ‘You cannot go,’” Bunn says, adding that JetBlue refunded her fare and that the hotel she booked will allow her to postpone her stay. In the meantime, Bunn and her husband will babymoon in California.

Worrisome Zika chatter has spread from playgrounds and Facebook “mommy groups” to travel agencies and medical offices, says travel agent Lauren Saiger of Manhattan-based SmartFlyer.

Like many of her clients, Saiger’s pregnant and had planned a trip to the Caribbean. “We rented a villa in Anguilla for my entire family, but then I heard about Zika in the area, and I was freaking out,” she says. Saiger’s physician insisted she follow the CDC’s mid-January advisory calling on pregnant women to postpone travel to the region. Doctors are also recommending women considering getting pregnant avoid any nonessential travel. Saiger canceled the trip and headed for Palm Beach with her family instead.

“My doctor is not an alarmist, and I traveled a few times to the Caribbean during my first pregnancy,” says the 32-year-old Cobble Hill resident. “I was super disappointed to miss the trip, but if there was ever a reason to cancel, the safety of your child is it.” Saiger says she received credit for the flights; the villa deposit will be deferred to a trip next year.

As New York women follow in Saiger’s tracks, hotels and airlines serving Zika-infested regions are scrambling to manage and contain the impact. Airbnb is offering refunds for pregnant women — and women trying to get pregnant — who cancel their trips. Carriers like American, United and JetBlue are also offering refunds for folks canceling trips due to Zika.

Meanwhile, resorts regionwide are beginning to report what could become a wave of room cancellations.

“We’ve only had two cancellations so far, and both were from New York,” says Samir Saab, CEO of Prohotels, which operates luxury boutique properties in Mexico and the Caribbean.

Four New York couples are among the first spate of cancellations at Viceroy’s Sugar Beach resort in St. Lucia, says p.r. director Molly McDaniel. “St. Lucia has had no reported cases and isn’t even on the risk list,” McDaniel says, “but we are offering cancellation without penalty to travelers who present a doctor’s letter giving proof of pregnancy.”

Travel insiders say the West Coast, Canada and — at least for now — Florida are where many pregnant New Yorkers have decided to vacation instead. “But now you’re beginning to hear that Florida may not be safe,” says Allison Stone, who’s 19 weeks pregnant and just canceled a long weekend sitting on the beach in Turks and Caicos. “From family to ‘mommy groups,’ there is a lot of pressure to stay home.”

Here’s a crash course on why Zika is freaking everyone out: