It’s a threat as fearsome as any of the other calamities that global warming might rain down on Hawaii: widespread outbreaks of insect-borne diseases that could decimate tourism, debilitate the state’s workforce, and cost millions to combat.

Scientists and health experts, who link the swift spread of diseases like Zika and chikungunya to a rise in global temperatures, say it’s only a matter of time before they arrive on Hawaii’s shores.

But Hawaii’s real enemy isn’t dengue fever or the Zika virus, it’s the mosquitos that spread them. And despite all the advances in medicine and technology in the last century, mosquito control seems to be something we’ve gotten worse at — not better.

Mosquito control is “the easiest thing for politicians to cut,” says David Morens, a senior scientific advisor at the National Institute of Allergy and Infectious Diseases.

“If there’s no epidemic going on, then (politicians say) ‘Why do we have all these people sitting around doing nothing?’” Morens says.  “They cut all the positions and then sooner or later the epidemic comes back and they say, ‘Why aren’t you doing anything about this?’”

Diminished public awareness about the need to combat mosquitos is also part of the problem, along with a reluctance to use the kinds of high-potency chemicals that kill mosquitoes but inflict collateral damage on the surrounding ecosystem.

Morens could have been talking specifically about Hawaii, which has reduced its mosquito-fighting resources, and appears reluctant to marshal the forces that have proven effective in the past.

These are problems that national public health experts say are unlikely to be resolved. Although places in tropical climates like Hawaii do need an active vector-control force, it would take a massive public investment to be able to solve the problem with state workers alone.

And because of the cyclical nature of governmental interest in pest control, the best chance for success moving forward is arming the public with the knowledge — and the sense of urgency — needed to keep mosquitoes at bay.

“The risk you have as a resident of Hawaii is not some general thing in your community. It’s right in your own house, and people need to understand that,” Morens said.

Hawaii Went To War During Past Outbreaks

The easiest way to track the diminished state response to mosquitoes is to look at the last three dengue outbreaks in the islands.

In 1944, when an outbreak on Oahu threatened the health of U.S. troops deployed in the Pacific, the military sent more than a thousand workers around the island to kill off the mosquito population — managing to eradicate the Aedes aegypti mosquito from the island entirely. 

In 2001, during a Maui outbreak that was the state’s first since World War II, the state spent more then $1.5 million on an effort that some criticized for being too intense and frightening to tourists.

Within 10 weeks of the start of the 2001 outbreak, the state created an emergency environmental workforce program that employed hundreds of people to conduct cleanups and mosquito sprayings.

The state hired a public relations agency to answer questions, distributed some 600,000 informational fliers, conducted on-site cleanups, hauled away trash from private residences, and even set up checkpoints on Hana Road where nurses handed out bug spray and information about the disease.

By the time the outbreak was over, the state had conducted mosquito sprayings at more than 2,500 residences, and cleanups at countless others.

After the outbreak was squelched, the state established a system to prevent recurrences.

But by 2009, the emergency environmental workforce had been assigned to other duties and the state’s vector control team had been gutted — along with efforts to monitor the arrival of new mosquitoes and track the population on Hawaii Island.

And so in 2015, when dengue began to spread across Hawaii Island, the Department of Health and Hawaii County Civil Defense were forced to to pull workers from other duties and call upon others to work seven days a week.

Diminished capacity has brought hard choices. For example vector control workers now spray an area up to 25 yards around houses where there has been a confirmed dengue case. The U.S. Centers for Disease Control and Prevention recommends 200 yards.

By Jan. 20, the county and state had surveyed 281 sites and conducted 578 sprayings on the Big Island — an impressive number given the staffing capabilities, but still far less than the state was able to accomplish 15 years ago on Maui. 

To help with staffing shortages, the Department of Health has been sending workers from other islands and departments. The county trained 40 of its employees to help with DOH vector control and “reached over 900 residents at 13 community meetings islandwide,” according to a compilation of efforts provided to Civil Beat by Hawaii County Civil Defense. 

“I think the world is going to have to get used to going overboard on infectious diseases a little bit.” — Sen. Josh Green

The Department of Transportation has placed bug repellent dispensers in the airports along with warning signs about dengue. But of the five dispensers in the Kona International Airport that Civil Beat checked Feb. 17 — small containers that look like soap dispensers mounted to walls and columns — only one worked.

The insect repellent chosen by the DOT is advertised as being a “vegan” and “cruelty free” combination of lemongrass, citronella, cedar, and mint oils. The makers of the product say it should be applied every two hours in hot areas and places where mosquitoes pose a health risk.

But the airport dispensers say it lasts for up to eight hours.

The coordinated effort in the Hawaii Island outbreak has been praised by the CDC, but area residents and legislators say the response was too slow and small.

The Maui outbreak ended with 119 confirmed cases of the disease. As of Feb. 19 there had been 259 confirmed cases of dengue on Hawaii Island since the outbreak began last October.

“If we had gone overboard in December then maybe this outbreak would have stopped at 80 or 100 cases,” says state Sen. Josh Green, who wanted the state to call up the National Guard at the start of the outbreak to help with mosquito eradication. “I think the world is going to have to get used to going overboard on infectious diseases a little bit.”

Stepping Up Efforts, And Seeking The Public’s Help

Part of the challenge with halting the spread of dengue on Hawaii Island is that it has geographic and population challenges that Maui did not. 

It’s by far the state’s largest island, and many homes are located in rural areas. There are a slew of organic farms that can’t spray certain kinds of pesticides without losing their status. And there are a lot of people who moved to the Big Island intent on living a more off-the-grid lifestyle in which they might not be connected to media and are harder to reach.

The Department of Transportation has plastered dozens of “Fight the Bite” posters at the airport, but in downtown Kailua Village — currently identified as a potential hotspot for the disease — there are few warning signs that dengue is near.

The county and state began a push to change that Feb. 17, gathering a crew of about three dozen people from different departments who went door-to-door in Kona handing out fliers and bug spray to residents and businesses. 

The goal was to start a “culture change” and increase awareness, said Kanani Aton, recently hired to handle communication outreach for the Hawaii County Civil Defense. It’s an effort to address what the CDC called a “critical deficiency” in communications staff in the state.

At the same time, Health Department workers fanned out across the village looking for places where mosquitos might be breeding.

Until last week, when the department hired several additional workers, Maricia Save and Eileen Passos were the only vector control inspectors on the west coast of Hawaii Island.

On Wednesday, the two women walked around Kona dressed in pants and long sleeve shirts, their weapons a clipboard and plastic jug of larvicide. Joining them were state employees from Oahu typically assigned to other departments. 

They spent more than 30 minutes walking around the grounds of a large hotel. The area appeared immaculate, but even so the two women found several potential trouble spots.

Passos, who started with vector control in 1992, was one of the workers laid off in 2009 when the state vector control division was cut by more than half.

Before the layoffs, Passos said a big part of her job was going door-to-door across the island inspecting homes and educating residents about preventing mosquito breeding. Such efforts have not happened in years.

In one neighborhood in the Captain Cook area, residents are trying to step in where vector control has not.

Karen Anderson and Krista Johnson have been raising awareness about dengue through a Facebook page that now has more that 1,400 members across the islands. They’ve also been raising funds to buy mosquito traps, and working with neighbors to place traps and clean up places where mosquitos like to hide.

About 15 people are participating in the neighborhood trapping program, Johnson said, including the caretakers of a small beach park. Other members of the Facebook group are trying to work on a science program that schools can use to educate students.

“Spraying is a reactive thing,” Johnson said. “What we want is a proactive thing moving forward.”

That effort may well be crucial, Morens said.

“A lesson from countries in southeast Asia is one of the best things you can do is public education,” Morens said.