MIAMI -- The first Zika-infected mosquitoes to be trapped on the U.S. mainland were caught in residential South Beach neighbourhoods, Miami-Dade County officials announced Wednesday.

The disclosure of four locations outside the Miami Beach Botanical Garden, which was previously identified as a breeding site for Zika-carrying mosquitoes, has been the subject of a recent dispute between state and local officials. The Miami Herald sued the county Sept. 16 after its public records request for the trap information was denied.

In a statement, Miami-Dade County Mayor Carlos Gimenez said Florida's Department of Health instructed the county on multiple occasions to withhold the addresses because of privacy concerns during their investigation into the Zika outbreak in Miami Beach.

The information was released Wednesday with permission from Florida's surgeon general, Dr. Celeste Philip, Gimenez said.

"This will be our protocol going forward: We will disclose the locations of any such traps that test positive for Zika to both the property owner and to anyone else who inquires," he said.

Philip emailed Gimenez on Tuesday afternoon to say the disclosure of all the trap locations was encouraged, according to an email forwarded by health department spokeswoman Mara Gambineri.

"As you know, this decision is one that is solely the county's to make," Philip wrote. "We encourage you to disclose the locations of these traps immediately so that your residents may remain fully informed and we are happy to serve as a resource to you in this process moving forward."

Gov. Rick Scott's office has made similar statements. Miami Beach is currently the state's only active Zika transmission zone, but additional infections are being investigated elsewhere in Miami-Dade County, according to the health department.

Gimenez's office maintains the county withheld the South Beach trap locations to follow the state's instructions.

Philip's email "is not consistent with what Miami-Dade County officials, including Mayor Gimenez, have been told throughout this process," said the mayor's spokesman, Michael Hernandez, who added that the health department's administrator in the county said at a news conference that the locations could not be released due to privacy concerns during an active investigation.

Four trap sites were located near short, pastel-colored apartment buildings with the Art Deco and Mediterranean Revival architecture that is symbolic of South Beach, according to addresses released in a statement from Gimenez's office.

Unlike the modern, luxury high-rises now common along the waterfront in South Beach, hedges, trees and other vegetation crowd the sidewalks and entrances around those buildings.

The fifth site at the botanical garden was previously released. All the traps were located within an initially small outbreak zone that now extends through much of Miami Beach.

Batches of mosquitoes from each trap tested positive for Zika on separate days between Aug. 22 and Sept. 9, according to the statement.

Inspectors treated storm drains, fountains, bird baths and other large containers to kill mosquito larvae and sprayed for adult mosquitoes at each property and surrounding areas within an eighth of a mile, said Gayle Love, spokeswoman for the county's mosquito control operations.

The apartment building surrounded by bromeliads and lush, leafy plants where University of Miami doctoral student Galen Treuer lives was the last site where Zika-infected mosquitoes were found. Health officials told him about the test results Wednesday morning, before the county's announcement.

"It's upsetting. I feel like I should have been told earlier," Treuer said. "I don't know what kind of risk they were trying to manage, but I don't think it was my exposure to Zika."

Treuer said he's noticed fewer mosquitoes since intense spraying began in South Beach, but he has still been bitten while sitting outside and he'd like to see the bromeliads removed from the property. Miami Beach officials have pulled the plants from city property and encourages residents to do the same because their thick leaves and cylindrical shapes can trap water where mosquitoes breed.

Aerial spraying over South Beach was performed four times over the last month to kill adult mosquitoes, and trucks also have been spraying a different pesticide targeting mosquito larvae in a broad area of Miami Beach for several weeks.

Each location tested positive just once, and subsequent batches from each site through Sept. 19 all tested negative for Zika, the county said.

County residents are urged to drain standing water from their properties to eliminate mosquito breeding sites and stop the spread of Zika and other mosquito-borne viruses, Gimenez said.

Zika can cause severe brain-related birth defects, including disastrously small heads, in pregnant women who become infected. The same mosquito species that spreads Zika also transmits dengue fever, and health officials said late Tuesday that a Miami-Dade County case was the state's second locally acquired dengue infection this year.