Mosquitoes trapped in South Beach have tested positive for Zika, the Florida Department of Agriculture and Consumer Services reported on Thursday — providing the first conclusive proof that insects in the U.S. are carrying the virus.
Florida health officials also reported two more local Zika infections in Miami-Dade, with one case in each of the two areas previously identified as transmission zones: a section of Miami’s Wynwood neighborhood and a 1.5-square-mile zone in Miami Beach.
The Zika-positive mosquitoes were found in three of 19 traps spread throughout the area of South Beach where the virus is spreading. One of the samples came from the Miami Beach Botanical Garden, which was closed on Monday for mosquito control. County officials are awaiting results on another batch of mosquitoes, though they wouldn’t say where they were trapped.
Officials did not say where the other two traps with Zika-positive mosquitoes were, citing health privacy laws protecting the identities of individuals at those locations.
But rather than react with alarm on Thursday, politicians cast the announcement as a reaffirmation of what they already knew.
“This find is disappointing, but not surprising,” Florida Commissioner of Agriculture Adam Putnam said in a written statement announcing the find. “Florida is among the best in the nation when it comes to mosquito surveillance and control, and this detection enables us to continue to effectively target our resources.”
The state’s agriculture department, which tracks statewide vector control, did not say when the mosquitoes were trapped or when they tested positive. But the announcement noted that 95 additional mosquitoes were tested after the positive samples and all were negative for Zika.
“That's a reason for hope,” said Janet McAllister, an entomologist with the Centers for Disease Control and Prevention’s Emergency Response Team dispatched to Miami this month.
In a press conference Thursday afternoon at County Hall, Miami-Dade Mayor Carlos Gimenez said the announcement doesn’t change the county’s mosquito control efforts, with inspectors on the ground spraying and dropping larvicide daily.
“This was not something that was unexpected,” Gimenez said.
The scientists in the room spoke more specifically about what this means for their investigation into the spread of the virus, saying that identifying positive mosquitoes indicates more precisely where active transmission is occurring.
Chris Braden, a medical epidemiologist with the CDC, said the discovery is likely due to traps being placed in the Beach earlier in the active transmission phase than in Wynwood, where no Zika-positive mosquitoes have been found to date.
But there is an upside to finding mosquitoes that carry Zika in Miami Beach: health officials can interview nearby residents and inspectors can target their spraying.
“It’s just another data point in the investigation in order to focus our control efforts,” Braden said.
Health officials are conducting 10 Zika investigations in Miami-Dade, including in South Beach, where inspectors continue to canvass the neighborhood, according to the Florida Department of Health’s top administrator in Miami-Dade, Lillian Rivera. She said the process of collecting blood and urine samples can be challenging when moving door to door.
“It’s tough,” she said. “But people are cooperating. We are getting samples.”
40,000 mosquitoes have been tested for Zika in Florida since May
In addition to the two local infections reported on Thursday, state health officials also confirmed seven more travel-related cases, including three in Miami-Dade, two in Broward, and one each in Osceola and Sarasota counties.
A total of 705 Floridians have contracted Zika this year, including 576 travel-related cases and 49 local infections. An additional 80 pregnant women in Florida also have tested positive for Zika, though the government will not specify where they live.
Miami Beach officials have known since last week that mosquito counts were high in three areas of the city after the health department notified them of its findings and its plans to test in those areas.
In light of the high counts, the city closed the botanical garden on Monday for inspections and testing, redirecting voters from the garden’s precinct to City Hall to cast their ballots in Tuesday’s primary election.
At a Zika community meeting in South Beach on Monday, Miami Beach City Manager Jimmy Morales said there were “high counts of mosquitoes on Lincoln Road.” He said city workers had destroyed dozens of bromeliads, which can serve as breeding grounds for the species of mosquito most capable of transmitting Zika, the Aedes aegypti.
The three positive samples reported Thursday are the first among 2,470 rounds of testing in Florida since May to test positive. In all, more than 40,000 mosquitoes statewide have been tested for Zika.
Department of Agriculture scientists tested the positive samples at the Bronson Animal Disease Diagnostic Laboratory in Kissimmee. Further testing at the Centers for Disease Control and Prevention and Florida Gulf Coast University confirmed the results.
Two weeks ago, the Centers for Disease Control and Prevention issued a travel advisory warning pregnant women to avoid the new South Beach zone, which stretches from Fifth Street north to 28th Street, and from Biscayne Bay east to the Atlantic Ocean. Tourism chiefs had hoped Zika wouldn’t land in the seaside resort city, and they’ve been anxious ever since. As of last week, hotel revenue in the Beach has continued to rise, according to the Greater Miami Convention and Visitors Bureau.
But there’s good reason to worry. According a national poll released Thursday, 48 percent of 1,211 adults surveyed said they would not feel comfortable traveling to places in the U.S. where people have been infected with Zika by mosquitoes, like Florida.
Over the past month, county and city officials have ramped up mosquito control efforts in South Beach and a one-square-mile section of Miami’s Wynwood neighborhood — identified on July 29 as the first place in the continental United States to have active spread of Zika by mosquitoes.
Mosquito counts have decreased in Wynwood, officials have reported. But the Beach, a dense urban environment with lots of lush landscaping that can serve as breeding grounds, presents a unique challenge for officials. Bromeliads, for example, are popular and provide a ripe environment for mosquito breeding because they trap water between their leaves.
“We’re also suggesting to all of our residents if they don’t have the time and ability to really maintain [bromeliads] well, to please remove them,” Morales said at Thursday’s press conference.
Zika cases reported by Florida as of Sept. 1
Number of Cases
Total cases not involving pregnant women
. . .
. . .
Cases involving pregnant women regardless of symptoms*
* Counties of pregnant women are not identified.
** Does not include local cases.
Source: Florida Department of Health