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What Happened with Zika

Five powerful positives that emerged in the wake of the 2016 Zika outbreakThink back two years to 2016. Never a day went by when there wasn’t something about Zika in the news. Troubling images of microcephalic infants. The disturbing revelation that this mosquito-borne virus was also sexually-transmittable. Zika was fueling angst up, down, and across the Americas. 

In the States, anxiety peaked when transmission models proved correct and the first locally-acquired cases of Zika were confirmed in South Florida at the end of July. Over the balance of 2016, 224 cases would be confirmed in Florida plus another five in Texas at the Mexican border. In addition, a staggering 36-thousand locally-acquired Zika cases were confirmed in the Caribbean U.S. Territories, some 35,000 in Puerto Rico alone. 

What did the uncertain future hold? Could any silver linings emerge from the cloud of this new public health threat?

To the layperson, it seems things have since grown quiet on the Zika front. From a disease incidence perspective, that’s true. 2017 witnessed only seven locally-acquired Zika cases in the contiguous U.S. and another 665 cases (a 98% reduction) across Caribbean Territories. In 2018, those numbers continued their precipitous drop to zero and 116, respectively.

Once the media coverage died down, Zika no longer dominated public awareness. But that doesn’t mean progress had been abandoned behind the scenes. Times of crisis tend to spur innovation and fortify (or foster) relationships where none existed before. The Zika outbreak was no exception. Here is our list of five clear positives that emerged from the Zika outbreak.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column width=”1/2″][vc_column_text]

#1  Partnerships

When interviewing personnel from leading districts among the vector control community and other public health partners, no positive development from the Zika outbreak was cited more often than how people and organizations – from both the public and private sectors – came together in a collaborative effort to safeguard public health. When the Zika transmission cycle was broken for the first time in Miami-Dade, all of these entities were present, on the ground, contributing to the success: local mosquito abatement professionals, state and federal agencies, pilots, biological and conventional pesticide manufacturers, field scientists, and academia. All played a role.

In fact, the collaboration was so instrumental, you might say each of the other positives we’ve identified are derivatives of these partnerships. Here are a few concrete examples.

All of Florida was on high alert in the months leading up to transmission. Miami-Dade County Mosquito Control and Habitat Management partnered with Valent BioSciences to train the PowerX team – Miami-Dade’s applicators – on equipment calibration and the WALS™ approach for delivering biological larvicides in the event of an outbreak. While aerial and ground applications of adulticides were the first line of defense once a transmission was confirmed, preparedness and execution of a wide area larvicide strategy figured heavily in breaking the transmission cycle.

Academic and agency partnerships were successful as well. Dr. Nathan Grubaugh is an Assistant Professor in the Department of Epidemiology of Microbial Diseases at the Yale School of Public Health. In his genomics lab, Grubaugh and his team do research to help understand how diseases such as Zika virus spread. Grubaugh saw the Zika outbreak as an opportunity to step up the way epidemiologists contribute to outbreak response efforts in real time.

A lot of the studies we do tend to be retrospective,” Grubaugh says. “Samples are collected during an outbreak and then academics get access to them after the fact. A year or two later, we’ll publish our findings and that’s the first time people really get to see our results. It’s useful information, but it isn’t much help during the actual transmission.”

In the months leading up to the Florida outbreak, Grubaugh’s postdoc lab at Scripps Research, led by Kristian Anderson, connected with the Florida Department of Health through friends working at Florida Gulf Coast University. Rather than getting samples later, Grubaugh’s lab offered to provide real time virus sequencing for the state as soon as clinical samples came in. This helped local agencies understand where the Zika cases were coming from and how many cases were coming from a given source – all important information in the midst of an outbreak.

“Without Zika, we would not have developed that relationship with the Florida Department of Health,” Grubaugh says.  “It’s hard to say how much impact we had in the grand scheme of things, but by establishing the relationship, we know we’ll be even more effective next time.”

“When written in Chinese, the word ‘crisis’ is composed of two characters. One represents danger and the other represents opportunity.” 

– John F. Kennedy

#2 Emergency Response Planning

Emergency response planning was a definite plus point from Zika, and all high-risk districts spent significant time and resources either developing or updating their response plans as a result. Perhaps the best example was the holistic approach taken in Southern California in 2017 and 2018. 

Information is a powerful weapon in the face of any crisis, but that power can be compromised wherever silos interrupt information flow. With Aedes populations already established in the county, Janice Hahn, a Los Angeles County Supervisor representing the 4th District, was determined to make sure those kinds of barriers didn’t undermine Zika response efforts in L.A.

Working closely with the LA County Department of Public Health (DPH), Hahn went on a mission to bring stakeholders to the same table and ready public agencies in the event of an outbreak. In addition to personnel from the LA County DPH’s Emergency Preparedness and Response Division and vector control officials from LA and neighboring counties, a plan development taskforce was put in place that included other key agencies such as first responders and the Department of Public Works. Ultimately, they would develop the Emerging Vector-borne Disease Response Plan.

Suzanne Kluh, Director of Scientific Technical Services for the Greater LA County Vector Control District (GLACVCD), says it was immediately apparent how important it was to have so many unique perspectives involved in plan development.

“One of the first things we realized is that if we’re going to be able to respond quickly and efficiently in the event of an emergency, we need to be able to communicate effectively,” Kluh says. “We all started out using different terminology – using different words for the same things – but we learned from each other and soon we were all speaking the same language.”

Kluh notes that having so many agencies involved gave the program clout and earned it support from other elected officials. As a result of the plan, coordinated field simulations and training exercises are conducted, and dozens of trained volunteers are standing by to supplement agency efforts in the event of a local transmission.

#3 Emerging Technologies

It might be an overstatement to say new technologies were instrumental against the Zika outbreak, but affirmation that fixed wing aircraft can be used in a WALS program was one incontrovertible outcome of the 2016 event. WALS is an application strategy for controlling mosquito larvae in small, cryptic, expansive container habitats that joins backpack, vehicle-mounted, or aerial spraying with a the target-specific biorational larvicide VectoBac® WDG (Bacillus thuringiensis subsp. israelensis Strain AM65-52), or Bti.

Fixed wing aerial application is common when adulticiding in emergency situations, but delivery of the active ingredient to the target is a greater challenge when larviciding. Without exception, adulticides are contact insecticides used to manage adult mosquitoes that may be carrying a virus. It follows that fixed wing aircraft (from an application altitude of 300 feet) are well positioned to deliver a chemical directly onto airborne adults. For biorational larvicides to be effective, however, Bti must be delivered into mosquito breeding sites – often small and/or hidden. This is no easy task from 300 feet in the air.

When the world’s first aerial WALS applications were done in the Florida Keys in 2010 to combat dengue-spreading Aedes spp., it was using helicopters. Since then, continued WALS development, marrying innovations in VectoBac product formulation and deep research into the aerodynamics of fixed wing application, yielded impressive results that went on display for the first time in Miami-Dade.

#4 Improved Public Awareness

As it pertains to vector-borne disease management, awareness among the general public has multiple facets. Certainly the Zika outbreak and all the media coverage it garnered raised awareness as to the threat of mosquito-borne disease. But for the mosquito abatement community, what’s more important is whether or not that awareness translates into behavioral changes among the general population that will help control efforts long term.

In Key West, for example, Public Information Officer Beth Ranson says awareness was already high before Zika. But in other areas of the Keys, there was still a need to educate.

“Key West residents had already experienced the dengue outbreak of 2009 – 2010. That’s when they became aware of mosquito control practices and how they could contribute to source reduction,” Ranson says. “But then when Zika emerged, awareness about the threat of mosquitoes had to increase throughout the rest of the County. We had to help people in the upper Keys understand that there are different kinds of mosquitoes and that different kinds of mosquitoes behave differently, and they could take an active role against breeding by dumping the standing water in their yards.”

In Greater LA County, Director of Community Affairs Kelly Middleton says that the Zika crisis prompted an acceleration of the region’s growing awareness since the introduction of Aedes to Southern California in 2013. 

“Awareness has absolutely increased here,” says Middleton. “News coverage and concerns over Zika in 2016 was a driving force, but the momentum has been sustained due to intensive biting pressure as Aedes has spread to new areas. Requests for service have doubled each year from the one prior; traffic to our website has increased an average of 30-40% each month from prior year; and the District’s social media following and engagement continues to grow. People are overall more aware of what constitutes a breeding source and what to do about it. Residents also report using repellents far more often (although not always effective repellents).”

#5 Increasing Surveillance Capabilities

In Northern California, at the Placer County Mosquito and Vector Control district, Director Joel Buettner doesn’t have to deal with invasive Aedes. Yet. While neither A. aegypti or A. albopictus have been detected, Placer and other California counties remain at risk. Buettner says the Zika outbreak was a real eye-opener for districts like his that don’t have to treat for Aedes currently, but might have to in the future.

“To run an Aedes program alongside our Culex program, we’d essentially have to be able to double our operational capacity,” Buettner says. “And when a crisis like Zika pops up, that really hits home. Fortunately, like lots of other districts, we were able to use some of the federal monies that were funneled through the state to get new traps and make some permanent upgrades to our surveillance capabilities.”

Statewide, the California Vectorborne Disease Surveillance Gateway, or CalSurv, is now fully online and providing districts with a futuristic surveillance tool. Districts use the system to monitor and report on disease incidence and to input or upload trap information and other surveillance data in real time. Since 2016, many districts have also begun to enter treatment data as well, providing a more in-depth pool of data. CalSurv also uses a disease habitat model that was developed with support from NASA and the National Oceanic and Atmospheric Administration. The model uses land-surface temperature data to predict where and when mosquito populations might peak.