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The Dallas County Mosquito Lab traps and searches through mosquitoes looking for any that carry the Zika virus. Photograph by LM Otero, AP Images

As Zika Advances, Can the U.S. Cope?

The Zika virus that is advancing on the United States is unlike any other outbreak the country has faced, and countering it will require an effort unlike anything the U.S. and its public health infrastructure has done before.

More than 300 delegates to an emergency summit held at the Centers for Disease Control and Prevention in Atlanta—state, local and tribal officials, members of nonprofits and representatives of private companies—heard that message over and over again Friday. Scientists, political appointees, and public health experts urged them to find a way to pull together groups who seldom have a reason to communicate: health departments, academic physicians, community well-baby clinics, birth-defect surveillance programs, mosquito-control workers, even garbagemen and gardeners.

All of that expertise, they said, will be needed to prevent a disease that is carried by mosquitoes that elude spraying, infects most of its victims silently, damages fetuses in ways that are still not understood, and may not be detected until well after it has arrived.

“Nothing about Zika is going to be easy or quick,” Dr. Thomas R. Frieden, the CDC’s director, said at a press conference halfway through the all-day meeting. “The control of this particular mosquito is hard, and though we are learning a lot quickly, there is still a lot we don’t know. There is an urgent need to learn more.”

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CDC Director Dr. Thomas R. Frieden addresses media during the Zika Action Plan Summit in Atlanta, April 1, 2016. Photograph by Maryn McKenna.

The meeting, which was standing-room-only in its main sessions and watched by 2,000 people online, revealed a simmering anger over Congress refusing to authorize money to combat the disease. The Obama Administration requested an emergency appropriation of $1.9 billion in February, but no funds have been  approved; Congress recommended the White House use money from last year’s Ebola response instead.

“I understand the polarization of politics in this country; I don’t understand why children are being made the center of it,” Dr. Edward McCabe, the chief medical officer of the March of Dimes, who spoke at the summit, said in a side interview. “We know what needs to be done, and it’s not stealing fron Ebola to fix this disorder. Congress needs to do the right thing.”

The financial stress of anticipating Zika is already hitting some jurisdictions. Daniel Kass, New York City’s deputy commissioner for environmental health services, told the meeting the city has already spent $3 million preparing for Zika, without ever having a case, and expects to spend $5-6 million more. Dr. Umair Shah, executive director of public health and environmental services for Harris County, Texas, which encompasses Houston, said his county expects to spend about half that much but added: “The real challenge is a lot of our daily work has been moved to the side.”

Dr. Georges Benjamin, executive director of the American Public Health Association, said during a break that health departments may struggle because financial support for public health has been so erratic: high just after the World Trade Center attacks and the first advent of West Nile virus, then sliding, only to rise during the 2009 H1N1 flu and then fall again until Ebola arrived. “When the money goes away, the jobs go away, and you’re left without the people you need,” he said. “It’s yo-yo funding, when what we need is to build a consistent approach.”

Zika has barely touched the U.S., compared to the devastation it has wrought in South America. (See “Here’s What we Know Now About Zika and Birth Defects.”) So far, according to the CDC’s most recent numbers, 312 U.S. residents have been infected while traveling in the Zika zone, including 27 pregnant women. No one has contracted Zika from a mosquito in the mainland U.S., but 6 people have caught sexually transmitted Zika from travelers, including two pregnant women, and one person has developed Guillain-Barré paralysis. In US territories—Puerto Rico, American Samoa and the U.S. Virgin Islands—349 people have been infected by local mosquitoes and three while traveling, including 37 pregnant women.

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Where Zika cases have been diagnosed in the United States as of March 30, 2016. Map courtesy of the CDC; original here.

Puerto Rico “could have hundreds of thousands of infections and tens of thousands of pregnant women infected,” Frieden said, but he declined to provide projections for the U.S. mainland. “We don’t want to  speculate what may happen,” he said. “We want to maximize our preparedness for what we can prevent.”

Without a vaccine, a disease-specific treatment or even a rapid diagnostic test, preventing Zika will fall on the expertise of mosquito control agencies, and summit attendees were clearly worried about the strain. (See “Disorganized Mosquito Control will Make U.S. Vulnerable to Zika.”) In some jurisdictions, mosquito control is a well-funded part of the health department. In others, personnel are so scarce that “it might be a guy who does water sampling during the day, and at night, it’s Chuck in a truck” spraying for nuisance mosquitoes, Stanton E. Cope, PhD, director of entomology and regulatory services for Terminix and president of the American Mosquito Control Association, told me.

A particular challenge, Cope added, is that existing mosquito control programs were built either to banish nuisance mosquitoes that interfere with tourism or to quell the night-biting mosquitoes that spread West Nile virus—but the Aedes species that transmit Zika bite during the day, breed in minuscule pools of water, lurk inside houses, and require different spraying equipment to dispel them and different traps to catch them so they can be tested to see whether they are carrying virus.

In a piece of irony, the CDC originated from a 1940s agency called the “Office of Malaria Control in War Areas,” and during the summit’s opening session, organizers showed a 70-year-old short movie about its work targeting Aedes aegypti, the mosquito that now spreads Zika. In the intervening decades, that insect slipped off the list of public health priorities, said Dr. Lyle Petersen, director of the CDC’s division of vector-borne diseases.

“It’s an important vector worldwide,” he told me. “It spreads dengue; there are several hundred milion cases of dengue every year. It spreads yellow fever, and right now we are having the first large urban yellow fever outbreak we have had in decades. It also spreads chikungunya. So it’s a bad actor.

“But what happened was, there’s a vaccine for yellow fever. And dengue was confined to the tropical world, and Zika wasn’t even on the horizon yet. So it became a very neglected mosquito, and now we are dealing with it again.”