West Nile to Zika: How One Virus Helped New York City Prepare for Another

Posted on by Mario Merlino, Assistant Commissioner, Pest Control and Veterinary Services, New York City Department of Health and Mental Hygiene

New York City helicopter used for larviciding.

No one told the Aedes mosquito that New York is the city that never sleeps.

The type of mosquito that can spread Zika virus (Zika) is most active during the early morning, day, and early evening. But New York is teeming with people during most of this time, meaning that our scientists had to find a way to reach the mosquito during pre-dawn hours. The solution? Wake it up, force it to take flight, and then kill it.

This is just one of many innovations New York is using to bolster the fight against Zika.

A tale of two mosquitoes

By the time the Zika outbreak was making news, causing birth defects and threatening pregnant women, New York City already had over a decade of experience in tackling mosquito problems related to the spread of West Nile virus. In facing Zika, we have been able to apply many of our existing resources and lessons learned from the West Nile virus response.

However, the mosquito that carries Zika is different than the one that carries West Nile virus, and it needs to be handled differently. New York is home to Aedes albopictus, which has been known to carry Zika – although, unlike the Aedes aegypti of the south, it has not yet been determined how likely Aedes albopictus is to spread the virus to humans in the United States. Because this is still unknown, people need to protect themselves.

To find out more about the risks, we need to catch the mosquitoes and test them. But we can’t use the same traps to catch the Aedes albopictus that we use to catch the West Nile virus-carrying Culex mosquitoes. Culex mosquitoes can be trapped with a combination of carbon dioxide and light. Aedes albopictus don’t fall for the same tricks. So we used traps that attract mosquitoes by releasing human pheromones.

Building on what we have

Aedes albopictus mosquito feeding.
Aedes albopictus mosquito

Meanwhile, some of the things we have always done for West Nile virus work well in the current response.

Although there are lots of ways to kill a mosquito, West Nile virus taught us that an effective response takes cooperation on many fronts. In New York, we have laboratories for testing, disease control experts to track cases in people, and a call center that manages tests and information from clinicians. Our communication department gets the word out because the best thing we can do for viruses like West Nile and Zika is educate people about how to prevent mosquito bites – wearing the right repellent, removing standing water, and staying indoors when you can.

Many of the resources we acquired for fighting West Nile virus are proving indispensable for fighting Zika. Ten years ago, we got a hand-me-down helicopter from the NYPD, and we’ve been able to use this for aerial spraying over marshlands and unpopulated areas. In the city, we use the same late-night spray trucks. A police car moves ahead of the truck, warning anyone who may still be out on the street. The distinctly New York voice bellowing from the loudspeaker (that of retired assistant commissioner Allan Goldberg) is even the same one we’ve always used.

 Sharing what we know

Zika presents us with a very steep learning curve, and it reinforces the need for transparent communication. We’ve set up an interactive website where we can share what we’re discovering with the public. We put out data on a weekly basis: people can zoom in and out on their screens to see where we’re finding mosquitoes. We want everyone to understand about the preventive work we’re doing to help keep Zika at bay.

The complex nature of Zika reveals the strongest and weakest points of the public health system. One thing in particular public health has always struggled with is how to change people’s behavior, which is critical and must happen if we want to stop Zika. We really hope that pregnant women or women who plan to become pregnant will not travel to areas with Zika, but it’s hard to stop people from visiting family or simply enjoying the world.

So far, all of the reported Zika cases in New York – including, as of August, 49 among pregnant women – have been the result of global travel. But just because we haven’t seen local transmission doesn’t mean the potential isn’t there.

This is why we’ve expanded our efforts by hiring extra staff and extending the areas where we do mosquito control and education. We need to continue to collaborate across agencies and in the field – and, in fact, all over the world – to manage a complex response that touches on so many areas. Working together and staying vigilant is our only hope for getting – and staying – ahead of this potentially devastating disease.

Read our other National Preparedness Month blogs:


Posted on by Mario Merlino, Assistant Commissioner, Pest Control and Veterinary Services, New York City Department of Health and Mental HygieneTags , , , , ,

2 comments on “West Nile to Zika: How One Virus Helped New York City Prepare for Another”

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    About how to wake up mosquitos and get them to swarm ; the trucks could carry a high frequency wave device similar to the plug in devices we have now, except larger to kill a larger portion of them.

    Knowing about this information is important but is the cure going to be dangerous? We know from previous applications of chemical solutions, there can be residual consequences. I hope the research team is really conscious of the effects on the human population. I am sure we applaud the diligent efforts. I send my thanks.

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Page last reviewed: April 27, 2017
Page last updated: April 27, 2017