Zika undercount hides extent of virus spread

That’s what medical experts are saying about Florida’s methods of reporting disease


MIAMI – For months, Florida Gov. Rick Scott and state agencies have reported almost daily on the public health crisis posed by the spread of Zika.

Florida Surgeon General Celeste Philip and Gov. Rick Scott announce that mosquitoes were spreading Zika in Miami Beach during a press conference on Aug. 19 at the Miami-Dade County Department of Health. At the gathering, Scott said three tourists had been infected in Miami Beach. But infections to out-of-state residents were not included in Florida’s Zika case count. (EMILY MICHOT/MIAMI HERALD/TNS)
Florida Surgeon General Celeste Philip and Gov. Rick Scott announce that mosquitoes were spreading Zika in Miami Beach during a press conference on Aug. 19 at the Miami-Dade County Department of Health. At the gathering, Scott said three tourists had been infected in Miami Beach. But infections to out-of-state residents were not included in Florida’s Zika case count.

From the first three travel-related cases identified in January, to the emergence of local Zika infections in Miami’s Wynwood neighborhood in July, followed by the discovery of mosquitoes infected with the virus in Miami Beach in September, the governor and state officials have vowed to keep Floridians informed so they can prepare.

“We’re going to put out accurate and timely information,” Scott told a group of reporters following a Zika roundtable with civic leaders in Miami Beach in August. “We want everybody to be prepared.

We all have to take this seriously.”

Not timely, accurate
But the information issued by the governor and state agencies has not been timely or accurate — cases announced as “new” are often several weeks old, because of a time lag in diagnosis — and excludes details that public health experts say would allow people to make informed decisions and provide a complete picture of Zika’s foothold in Florida.

“I don’t think the message has been strong enough, in terms of ‘We have a problem,’” said Arthur Caplan, director of medical ethics for New York University Langone Medical Center. “It makes no sense — unless you see it through the eyes of the impact on tourism. I think that’s money driving reporting rather than public health.”

Over the past month, as local Zika infections have spread beyond Miami-Dade, with cases cropping up in Broward, Palm Beach and Pinellas counties, Florida officials have:
Stopped providing detailed information on epidemiological investigations into local Zika infections;
Refused to identify all the locations where Zika-positive mosquitoes were trapped in Miami Beach;
And underreported the number of local Zika infections in Florida by excluding anyone who is not a state resident.

Methods criticized
Not reporting local Zika infections to tourists is particularly egregious to Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

“That’s just wrong,” he said. “To get a true picture of what’s going on in Florida, you want to know, among anyone who was in Florida, who acquired it there. … That’s how it should be counted. If they’re not, then that sounds to me like they’re trying to minimize their number of cases.”

The Florida Department of Health has been criticized before for its disease reporting methods, most notably for taking hundreds of HIV cases off the books in February as then-State Surgeon General John Armstrong was under fire for a spike in infection rates.

The agency later explained that some cases had been shifted to the year of diagnosis or to the state where the individual resides to avoid double counting.

Philip responds
State Surgeon General Celeste Philip has said that, similar to HIV reporting, Florida’s method for documenting local Zika infections adheres to standards set by the federal Centers for Disease Control and Prevention. CDC guidelines state that Zika cases are counted in the state where the person lives — regardless of where exposure might have occurred.

“There has been a lot of interest in how we count HIV cases, and it has to do with place of residence,” Philip said following an August news conference on Zika.

“So the governor announced that we had three (Zika) cases associated with tourists (in Miami Beach), and we were very transparent about where they came from. But in terms of the technical count for the state, CDC will count them in their (state) of residence.”

Counting concerns
But Florida chooses how to report local Zika infections to the public, Osterholm said, and counting all infections in the state is “standard protocol, in terms of how disease reporting is done.”

“You’re trying to figure out where they were exposed,” he said. “If somebody catches malaria on a trip and comes back to Minnesota, we don’t count that as malaria in Minnesota.”

On Sept. 7, the state health department, in response to questions from the Miami Herald, said eight out-of-state residents have contracted Zika in Florida but are not included in the total count.

Mara Gambineri, a spokeswoman, said the health department tracks those cases “as they are still important for us to be aware of, but the cases are not reported in our case counts. The department reports cases of Florida residents.”

That means there have been at least 64 local Zika infections in Florida this year, not the 56 cases reported so far by the health department.

Out-of-state cases
On Aug. 19, the governor, visiting the Miami-Dade Department of Health, reported that three tourists were infected within a 1.5-square-mile zone of South Beach.

Scott said the visitors came from New York, Texas and Taiwan. But neither the governor nor the health department said those cases would be excluded from the state’s tally of local Zika infections until a week later when the Herald asked.

Gambineri did not respond to questions about the place of residence for any of the out-of-state people infected in Florida.

However, one of them might be another New Yorker. A woman from Brooklyn who has been living and working on Miami Beach since Aug. 5 contacted the Herald to report that she had contracted Zika in Florida, and that the state had been unaware of her case even though she tested positive at a commercial lab, which sent her results to New York’s health department.

Confirmed cases
The vast majority of infections in Florida have been imported by residents who caught the virus while traveling abroad in places where Zika is widespread.

Statewide, health officials have confirmed 700 travel-related cases, including 80 pregnant women, as of Sept. 9. The health department has refused to say how many local infections involve pregnant women.

The agency also has stopped issuing details of active investigations into local Zika cases. On Sept. 1, the health department began reporting only a summary of the total number of investigations in each county.

Previously, the agency had listed each investigation by county, with the number of people tested for Zika and the results of those tests.

Gambineri explained the change in an email: “The department is working to ensure the information is easy to understand. It had become confusing.”

More info needed
Communicating a public health crisis requires more than a tally of infections and active investigations, said Andrew Pekosz, a professor of molecular microbiology and immunology with Johns Hopkins University’s Bloomberg School of Public Health.

“There’s no one piece of information in an outbreak like Zika that is absolutely, 100 percent critical to know because everything is contextualized,” he said.

Pekosz said the time and effort required to investigate cases, wait for diagnostic test results and verify local spread of the virus can slow the flow of information and make it difficult for public health officials to communicate the relative risk of contracting Zika.

“The most important thing,” he said, “is to identify the geographic areas where there’s a high potential of mosquito transmitted cases.”

Being general
But while the health department has identified two general areas in Miami-Dade with ongoing spread of Zika, Florida officials have chosen not to inform the public about precisely where they found mosquitoes that carry the virus.

After announcing on Sept. 1 that mosquitoes in three Miami Beach locations had tested positive for Zika — a first in the nation — Florida’s Department of Agriculture and Consumer Services identified only one of the places: Miami Beach Botanical Garden, which had closed three days prior. A fourth batch of mosquitoes in Miami Beach that tested positive for Zika was announced on Sept. 9.

The agriculture department has refused to identify all locations, citing exemptions under Florida statutes governing the sharing of confidential or exempt information and investigations into the spread of the virus, said Jennifer Meale, a spokeswoman.


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