Scottsdale City Council met for an Oct. 25 study session to discuss the threats and potential need for action regarding the looming threat of the Zika virus.
While the city and county are actively trying to fight a number of mosquito-transmitted viruses, residents are being asked to monitor their own backyards in order to curb the harvesting of mosquito eggs.
Maricopa County Department of Public Health Epizoologist Craig Levy gave a presentation and explanation about Zika to the city council and audience, before different city departments outlined their responsibilities in protecting residents from the mosquito-transmitted disease.
Zika is transmitted through the bite of Aedes aegypi mosquitos. These types are often known as aggressive daytime biters, according to Mr. Levy. If a person has Zika in their blood and is bitten by a mosquito, that mosquito can pass it on by biting another person.
“Infected people traveling from Zika areas are the reservoirs, they are the mechanism in which the virus is traveling from point A to point B, and then our own Aeds aegypi feeding on those returning travelers are the mechanism as to what could potentially get it started here,” said Mr. Levy during the study session.
The virus can also be transmitted prenatally, sexually and through possible blood transfusions, said Mr. Levy, so now blood supplies are being screened for the virus. The prenatal cases of Zika is known to cause birth-defects, one of the reason the public has become so aware of this particular virus, he said.
This is also the first mosquito virus to be transmitted sexually, he said, which shocked those in the public health sector.
“At this particular time there is a lot we still don’t know about Zika infection during pregnancy, but it does appear that infection during the first and second trimesters probably are more likely to have adverse out comes than those having come late in pregnancy,” he said.
Mr. Levy says this type of mosquito is not native to Arizona, but because we as humans have historically tropicalized the desert, is one of the reasons there is a problem.
Common symptoms of Zika are mild and include fever, rash, joint pain, red eyes, muscle pain and headache. Four out of five people infected with Zika don’t become ill.
“Probably 99 percent of the sources are coming out of backyard clutter and containers,” said Mr. Levy.
“It does not take a lot of water to breed them. Out of one car tire, for example, you can get over 1,000 mosquito larvae. It does not have to be a container with water, they are actually hatched beside the container and they can survive for weeks or months before there is more water from monsoon rain or from a sprinkler coming on. So dry containers are also part of the problem because they are a source of viable eggs.”
Prior to 2015, Zika virus outbreaks have occurred in areas of Africa, Southeast Asia, south and Central America and the Pacific Islands.
In May 2015, the Pan American Health Organization issued an alert regarding the first confirmed Zika virus infections in Brazil.
There have been 27 cases in Maricopa County, said Mr. Levy, all of which have been imported and not locally acquired. There is no vaccine or specific treatment for the Zika virus.
Additionally, other mosquito-transmitted diseases are of concern and thriving in Maricopa County.
The county is asking residents to be checking and policing their own yards for containers and clutter that could be breeding these mosquitoes.
“You need to remove it, throw it away, cover it or store it in a garage or in a shed so that it does continually dry and fill, and dry and fill with water,” said Mr. Levy.
Fight the bite day and night
City staff has taken several steps to thwart the issue of standing water and mosquito breeding areas around Scottsdale, said Scottsdale Emergency Manager Brent Olson.
“Staff is very concerned about that, as is our residents,” Mr. Olson said.
One area of concern has been the WestWorld east basin, he said. However, that basin is treated regularly to mitigate the mosquito threat. Additionally, the basin would not be a concern for Aedes aegypi mosquitos because they stay near areas where humans frequently are.
“Data will show the east basin does not present a threat of Zika to surrounding neighborhoods,” said Scottsdale environmental employee Sam Brown. “Zika virus likes to stay close to home in backyard patios and near containers.”
City departments have different treatment and water elevating methods for various forms of standing water, but 99 percent of the Zika mosquitoes are breeding in backyards, officials said.
“The city is pro-actively trying to deal with this threat, actively treating water, actively trying to make sure it drains,” said Mr. Olson. “We are trying to get the word out to people but we need the residents to treat their yards as well. This is a container mosquito that we’re concerned about with Zika.”
The city council ended the study session by asking Mr. Olson and his team to regularly update council on different treatments and progress it’s making with standing water throughout the city to alleviate all mosquitoes, not just Aedes aegypi.