FILE - In this Jan. 27, 2016, file photo, an Aedes aegypti mosquito known to carry the Zika virus and the Dengue fever, is photographed through a microscope at the Fiocruz institute in Recife, Pernambuco state, Brazil.
Felipe Dana / AP
For the first time, Aedes aegypti mosquitoes have been found in Oregon. Emilio DeBess is the state public health veterinarian based at the Oregon Health Authority’s Public Health Division.
He says the insects are a national concern ”because they can carry and transmit various diseases that can have serious health consequences such as Zika virus, chikungunya, dengue and yellow fever.”
The insect was found this summer in Jackson County while officials were monitoring other kinds of mosquitoes. Officials are continuing surveillance and OHA is working with other states to learn more about it. Infection risk from the mosquito is currently low.
The insect, also known as the yellow fever mosquito, was found in California in 2013 and has been progressing northward since. DeBess joins us with more on this mosquito, why it’s important to track these insects with county and federal agencies like the Centers for Disease Control and Prevention, and how changing climates are playing a role in the insect’s spread.
Note: The following transcript was transcribed digitally and validated for accuracy, readability and formatting by an OPB volunteer.
Dave Miller: From the Gert Boyle Studio at OPB, this is Think Out Loud. I’m Dave Miller. The kind of mosquito that can carry and transmit Zika virus, dengue and yellow fever was found in Oregon for the first time this summer. The discovery came in Jackson County where officials were actually looking for other mosquito species. Emilio DeBess is the public health veterinarian at the Oregon Health Authority. He joins us now to talk about what this discovery means. Welcome to Think Out Loud.
Emilio DeBess: Hi. Thank you for having me.
Miller: So we’re talking about this discovery that your team made back in the summer. Can you give us a sense for what mosquito surveillance looks like? Where does it happen? What does it entail?
DeBess: Yeah. So mosquito surveillance happens in about 13 different districts throughout the state of Oregon. And they’re placed around the Tri-County area, Southern Oregon and Eastern Oregon – Umatilla, Morrow County, Baker, Malhuer County. So we have a few districts that collect mosquitoes on a regular basis and do identification, which means speciate them and then test them for a number of pathogens that we’re interested in, such as West Nile.
Miller: Was it surprising to you to find this particular species in July?
DeBess: I have to say yes … although we knew that if you look at the history of this mosquito on the West Coast, California first identified the mosquito back in 2013. And that was in the LA area. We knew that I had moved up the state, with the latest finding in 2020 in Shasta County. So it was kind of expected, but at the same time, surprising to find the mosquito.
Miller: How worried should Oregonians be that this mosquito was discovered? And I should say there was one at first and my understanding is that dozens more have been found?
DeBess: Yeah. So we have identified about 130 so far in about 26 different traps. And the good news, if you wanna call it, is that it’s actually localized to a town at this point and we have not seen it in other places around Jackson County.
Miller: That’s the good news. If you were looking for bad news, what is it?
DeBess: Well, then the bad news would be widely spread throughout the county, potentially affecting other counties like Klamath County that has a vector control district, and obviously up the I-5 corridor into Eugene, the Portland area – the more populated areas.
Miller: But just to be clear, my understanding is that these mosquitoes can carry and transmit Zika virus or dengue fever, say. But it’s not that they necessarily have those viruses or pathogens?
DeBess: That is correct. They need somebody, a human, that is infected with dengue or Zika or chikungunya to be a source of the infection so they can pass it on to someone else through a blood meal.
Miller: And so if there are very low likelihoods of people, say, right now having Zika in Talent, Oregon, then there’s a very low likelihood that somebody who gets bitten by a mosquito there would get the virus through that mosquito. Is that a fair way to put it?
DeBess: Yeah, that is correct. And obviously, we track the number of people that have tested positive for any of those viruses. And obviously a lot more information is going to be going out to a lot of the population about, if you travel overseas, if you develop dengue fever or Zika, to make sure that you protect yourself against mosquito bites.
Miller: What climates do these kinds of mosquitoes that are, I guess, called Aedes aegypti … where have they normally been found?
DeBess: So the mosquito came from Africa. We’ve seen it in Asia. In fact, the lucky bamboo was potentially one of the sources in Los Angeles. We see a fair amount of this mosquito in the southeast part of the United States. I was talking to Nevada. They have mosquitoes. The Las Vegas area has mosquitoes. So it seems to be prevalent in the southern belt of the United States.
Miller: Is this spread now potentially tied to climate change?
DeBess: I think there are multiple factors, right? So a lot of people are moving around, they move with their plants that could potentially have the mosquito larvae within the roots of the plant. It could be through a trailer in a truck. Obviously, climate has an impact because it’s providing the perfect habitat, temperature, humidity for the mosquito to thrive, to do well. So multiple factors are certainly in play here.
Miller: Emilio DeBess, thanks very much.
DeBess: Thank you
Miller: Emilio DeBess is the state public health veterinarian at the Oregon Health Authority.
Contact “Think Out Loud®”
If you’d like to comment on any of the topics in this show or suggest a topic of your own, please get in touch with us on Facebook, send an email to thinkoutloud@opb.org, or you can leave a voicemail for us at 503-293-1983. The call-in phone number during the noon hour is 888-665-5865.