NEW YORK (CBSNewYork)– Spraying from the air to try to stop the Zika virus began early Thursday in the Miami area.

“The mosquitoes in the traps all died which means it was effective,” Miami-Dade Mayor Carlos Gimenez said.

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The target is the Aedes Aegypti mosquito, CBS News’ Weijia Jiang reported.

Centers for Disease Control Control and Prevention Director Tom Frieden met Thursday with local officials to talk about the plan of attack.

“I’m very impressed with how intensive the control activities are. They have over 100 teams in the field. They are going to ensure that people hear the key messages which is get rid of anywhere this mosquito can breed,” he said.

Efforts to fight mosquitoes on the ground area also being ramped up, but health officials acknowledged the aggressive spraying isn’t working as well as they hoped — mosquitoes have transmitted the virus to 15 people.

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The Wynwood transmissions reportedly were made within a tiny area.

“It’s a small area and what Florida has done is place a buffer zone and that 500 square foot area, so it gives us a margin of safety,” CDC Director, Dr. Tom Frieden explained.

Medical experts said aerial spraying was killing large portions of mosquitoes.

“We are very encouraged with the initial results which showed large portions of mosquitoes killed,” Dr. Frieden said.

The Florida Surgeon General confirmed that no new cases have been confirmed, but Dr. Frieden advised caution.

“We would not be surprised to see additional infections diagnosed in this 500 square foot area. That’s the way Zika works,” he said.

So far 2,300 people have been tested for Zika across Florida, including 200 people in the Zika zone. The governor of Florida visited local businesses, trying to reassure residents and tourists.

“We’re telling everyone, this is a safe state. We have one square-mile that we think might have locally transmitted Zika. We’re not seeing new cases. People should come to our state,” Florida Gov. Rick Scott said.

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Pregnant women are at greatest risk because the virus can cause devastating birth defects. Earlier this week , the CDC advised pregnant women to avoid the Wynwood neighborhood of Miami.

As Hank Tester of WFOR-TV, Miami reported, Thursday was a pleasant summer night in Wynwood with people out in the streets, but cautious about Zika.

With some businesses saying business was down 30 percent, the bar and performance venue Gramps in Wynwood had two sellout comedy shows on Thursday night.

“We take spray breaks and go outside and spray up,” owner Adam Gersten said.

Gersten was not sure why his business is packed in the middle of a Zika scare, but it is.

“Anybody who is making the choice to come out, they have taken the precautions that are right for them,” he said.

Meanwhile, pregnant women in the Tri-State area are on edge, CBS2’s Christine Sloan reported, with many cancelling vacations to Florida and the Caribbean.

“I am actually from Puerto Rico too, so I have family that are there that I want to visit, and I can’t go,” Yonkers resident Natasha Navarro said.

Some airlines, including United, are offering refunds to Zika-affected areas because of the CDC travel warnings.

Dr. Robert Amler said while Zika-carrying mosquitoes were only found in the small community of North Miami, everyone needs to be cautious to prevent mosquitoes as they could be capable of transmitting through breeding. It’s suggested that locals get rid of standing water.

“It could be as small as a bottle cap turned upside down where they like to breed … to a small pond to a puddle,” Amler said.

Experts also suggest cleaning gutters and keeping screens on windows.

“It’s not just standing water mosquitoes, but also weeds and grass… shady areas they like to stay on hot days… so keep them trimmed,” he said.

No mosquitoes carrying the virus have been found in the New York area. The good news is mosquitoes don’t travel far, only 400 feet from where they’re born, so by staying vigilant you can help keep them away.

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