MIAMI — There’s no official warning to stay clear of Florida, but the crowds that usually wander among the bold street murals in Miami’s trendy Wynwood arts district may be thinner after reports that mosquitoes in the area have spread the Zika virus on the U.S. mainland for the first time.

Officials are trying to reassure tourists they’ll be safe when visiting Florida’s theme parks and urban arts districts. But some Miami residents said Friday they were stocking up on mosquito repellent and planning to bring lunches to work instead of sitting at outdoor cafe tables.

No mosquitoes in Miami or elsewhere in Florida have tested positive for Zika, but four Miami-area patients who contracted the disease did not get it by traveling to an outbreak country or from sex with an infected person. Officials say those four are apparently the first of over 1,650 U.S. Zika cases to have gotten the disease from a mosquito in the U.S.

Gov. Rick Scott pinpointed the infections to Wynwood, and the state’s agriculture commissioner issued a mosquito declaration that triggers aggressive mosquito control efforts within a 200-yard radius of the homes of the patients with locally acquired cases.

The director of the U.S. Centers for Disease Control and Prevention said Friday there were no plans to recommend limiting travel to South Florida.

Miami-Dade Mayor Carlos Gimenez said he’s confident in local mosquito control because they’ve successfully fought off outbreaks of West Nile, dengue fever and chikungunya. Orange County Mayor Teresa Jacobs said repellent is sold at entrances to the Orlando area’s three major theme parks.

“If you’re coming to Florida as a tourist, if you’re coming to the theme parks, then you’re coming to some of the safest places in the world because they have mosquito control down like no place else,” said Jacobs.

The theme parks are known for keeping their properties well-maintained. Officials say the parks also have far bigger mosquito control operations than local governments.

“They keep their property very clean, spic and span,” said Carl Boohene, director of mosquito control in Polk County, home of LEGOLAND Florida.

The state activated a Zika information hotline for residents and visitors, and health officials are reminding people to wear repellent. Visitors to South Florida have been urged to put off donating blood.

Anyone bitten by mosquitoes in Florida could help public health experts trying to track the disease through the Mosquito Byte! app. Women who are pregnant or thinking of becoming pregnant should take extra precautions.