Mosquito & Vector News

Artificial Light May Make Aedes Aegypti Mosquitoes ‘Abnormally’ Active At Night, Study Shows

From the International Business Times
October 21, 2020

Aedes aegypti mosquitoes, which are carriers of dengue and Zika viruses, are known to be active biters during the daytime, but a team of researchers has found that artificial lights can “abnormally” increase their biting behavior even at night.

Aedes Aegypti mosquitoes transmit various mosquito-borne diseases such as dengue fever, chikungunya, yellow fever and Zika fever. The species mostly bite in the early morning and in the afternoon hours when there is light, but what happens when they are exposed to artificial lights at night?

To find out, a team of researchers conducted an experiment wherein the study’s first author, Samuel S. C. Rund of the University of Notre Dame’s Department of Biological Sciences, let mosquitoes bite him under certain conditions including during daytime, at night, and at nighttime while exposed to artificial light. They then measured the mosquitoes’ blood-feeding behavior.

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Kern County reports first 2020 West Nile Virus case

From the Kern Valley Sun
October 14, 2020

In an Oct. 6 news release, Kern County Public Health Services said it has received confirmation of a human case of West Nile Virus (WNV), the first reported case in the county for 2020.

West Nile Virus is a mosquito-borne disease that normally spreads during the summer and early fall months. While it is not fatal to most people, it can pose a serious risk in certain individuals, leading to death in the rarest of cases. Approximately 20% of infected persons will experience symptoms such as headaches, fevers, joint pain, body aches, nausea and possibly skin rashes.

Less than 1% of people experience severe symptoms in which the virus affects the brain and nervous system. These symptoms can include confusion, neck stiffness and high fever. The Department of Public Health Services urges individuals experiencing symptoms related to the virus, especially after being bitten by a mosquito, to contact a medical care professional for further information.

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West Nile virus symptoms are similar to COVID-19 at first, experts say

From KXXV
October 12, 2020

According to the CDC, more than 30 states are reporting West Nile virus infections in people, birds or mosquitoes. Early symptoms of West Nile are similar to any virus or the common cold. These days, that means it’s hard to differentiate from COVID-19.

In Los Angeles, it’s a big job to mitigate mosquitoes. The Greater LA County Vector Control District serves nearly 6 million people in 35 cities. So far this year, more than 230 mosquitoes have tested positive for West Nile.

“Every year, our mosquito season seems to get longer and longer and that goes into it being warmer and warmer,” said Anais Medina Diaz, the public information officer for the LA County Vector Control District. “Now we’re seeing mosquito season go from March to the end of October, sometimes into the beginning of November.”

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More mosquitoes test positive for West Nile virus in LA County

From the Antelope Valley Press
October 12, 2020

LOS ANGELES — Twenty-six more mosquito samples tested positive for West Nile virus this week in Los Angeles County, bringing to 264 the number of positive samples so far this year, vector control officials reported Friday.

The mosquito samples all were collected from areas previously identified as positive for the virus, according to the Greater Los Angeles County Vector Control District. The highest totals of mosquitoes that have tested positive this year were reported in: Encino and North Hollywood with 14 each, Valley Village with 13, Van Nuys and Pico Rivera with 12 each and Studio City and Toluca Lake with 10 each.

West Nile virus is endemic in Los Angeles County, and warm temperatures can increase virus activity and mosquito populations, according to the GLACVC. As of Oct. 2, 93 West Nile human cases have been reported in California this year, 27 of which were identified by the Los Angeles County Department of Public Health.

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More Mosquitoes Test Positive for West Nile Virus in L.A. County

From NBC Los Angeles
October 9, 2020

Twenty-six more mosquito samples tested positive for West Nile virus this week in Los Angeles County, bringing to 264 the number of positive samples so far this year, vector control officials reported Friday.

The mosquito samples all were collected from areas previously identified as positive for WNV, according to the Greater Los Angeles County Vector Control District. The highest totals of mosquitoes that have tested positive this year were reported in: Encino and North Hollywood with 14 each, Valley Village with 13, Van Nuys and Pico Rivera with 12 each and Studio City and Toluca Lake with 10 each.

West Nile virus is endemic in Los Angeles County, and warm temperatures can increase virus activity and mosquito populations, according to the GLACVC. As of Oct. 2, 93 WNV human cases have been reported in California this year, 27 of which were identified by the Los Angeles County Department of Public Health.

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West Nile Virus claims lives of two people in Merced County, abatement district says

From the Merced Sun-Star
October 8, 2020

West Nile Virus has led to the deaths of two individuals over age 50, a Merced County Mosquito Abatement District news release reported.

Each person had underlying health conditions prior to their death.

Although the fatalities were reported on Thursday, both occurred during September, the release said.

As of Oct. 2, a total of 93 known West Nile Virus cases have been reported in California this year. Four deaths have been traced to the virus, meaning half of fatalities statewide are Merced County residents.

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There are more mosquitoes in Tulare County, but not as many carrying disease

From YourCentralValley.com
October 8, 2020

VISALIA, California (KSEE) — October is usually when the number of mosquitoes declines – but in some parts of Tulare County the number is going up.

While the number of diseased mosquitoes is down from last year, mosquito-transmitted diseases like West Nile virus are still being found in humans.

Inside the lab at the Delta Vector Control District, one water sample contains an abundant amount of larvae. Petri dishes also line the counters, filled with hundreds of mosquitoes caught in traps.

General Manager Dr. Mustapha Debboun said the Central Valley’s prolonged heat has made ideal mosquito breeding conditions.

Recently, there’s been an uptick in neighborhoods in northwest Visalia. The district conducted targeted treatment in some of them Thursday morning. However, the number of mosquitoes found carrying viruses is down from 2019. So far, only 139 mosquitoes have been found with West Nile virus, while 39 have been found with St. Louis Encephalitis virus.

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Sacramento officials find mosquitoes that can carry Zika virus near Arden Arcade park

From the Sacramento Bee
October 7, 2020

Even as the Sacramento Valley cools down, the yellow fever mosquito is being discovered in traps in new areas. Some were found this week near Cresta Park in the Arden Arcade area, the Sacramento-Yolo Mosquito and Vector Control District announced Wednesday.

This aggressive day-biting pest, more formally known as Aedis aegypti, can carry not only yellow fever, but also Zika virus, dengue and chikungunya. While mosquitoes breed more quickly during the heat of summer, these new reports show local residents shouldn’t let down their guard this autumn.

“Your assistance is critical! If you are being bitten throughout the day or notice more mosquitoes in your yard, please give the district a call to request a free inspection,” said Gary Goodman, the district manager, in a news release.

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Mosquito tests show no further signs of West Nile virus

From the Half Moon Bay Review
October 7, 2020

Mosquito tests for West Nile virus done last week came back negative on Thursday, after a dead American crow in South San Francisco was found to have the virus.

The bird signaled the first indication of West Nile virus in San Mateo County since 2018, according to a statement by the San Mateo County Mosquito and Vector Control District.

Following the report, the district deployed mosquito traps in the neighborhood where the dead bird was collected.

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More mosquitoes, one human test positive for West Nile Virus in Valley

From the Antelope Valley Press
October 7, 2020

LANCASTER — More mosquitoes collected from mosquito traps in Palmdale have tested positive for West Nile virus (WNV). 

One trap was located near 25th Street West and Avenue P-8. The other trap was located near 30th Street East and Avenue R. To date, there have been 13 West Nile positive mosquito samples for the 2020 mosquito season. 

Public Health also reported another human case of West Nile virus within District boundaries, which brings the local human West Nile virus count to seven cases.

The District would like to reinforce the importance of keeping the mosquito population low. The lower the mosquito abundance, the less opportunity there is to have an issue with mosquito-borne disease transmission. Brenna Bates-Grubb, community outreach specialist for the AVMVCD said that “There is no vaccine or cure for West Nile virus, so the best way to stay safe is through prevention of mosquito bites. Prevent mosquitoes from breeding around your home by eliminating sources of standing water at least weekly and wear mosquito repellent when outdoors.”

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INVASIVE AEDES MOSQUITO FOUND IN SANTA BARBARA COUNTY FOR THE FIRST TIME

From Edhat Santa Barbara
October 3, 2020

Source: Mosquito and Vector Management District of Santa Barbara County

The Mosquito and Vector Management District of Santa Barbara County has confirmed the presence of the non-native Aedes aegypti mosquito in Santa Barbara County. Photos of a suspect mosquito caught at a home in the Hope neighborhood in Santa Barbara were submitted to the District’s website by an alert resident.  The suspect mosquito specimens were collected from the residence located near the intersection of N. La Cumbre Rd. and Foothill Rd. and tentatively identified as Aedes aegypti at the District laboratory. An additional specimen was collected from a trap set up at the residence where the mosquitoes were found and it was positively identified as Aedes aegypti, the yellow fever mosquito. Mosquito district staff currently are setting up additional traps, conducting property inspections, and passing out informational brochures in the surrounding neighborhood. 

Aedes aegypti is native to Africa but has spread throughout many regions of the world. This mosquito was first detected in California in 2013 and since then has spread throughout southern California and the Central Valley. Aedes aegypti can transmit viruses such as Dengue, Zika and Chikungunya and the virus that causes yellow fever but, fortunately, these diseases are not locally transmitted in California. However, this mosquito can be extremely bothersome, biting both during the day and at night and can be found both indoors and outdoors. Residents in areas where the mosquito has become well established call them “ankle biters” due to their habit of biting around the ankles. Aedes aegypti prefer feeding on humans and stay close to human dwellings where they will lay their eggs in practically anything that contains stagnant water including buckets, tires, birdbaths, containers of all kinds, and plates under potted plants. They can even develop in water held in plants, such as bromeliads. Aedes aegypti mosquito larvae can complete their development in the amount of water that would fill a bottle cap. Residents are urged to remove all sources of stagnant water both inside and outside of the home and scrub the sides of the containers because the eggs can survive without water for many months.

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OC Cities Battle Explosion Of Non-Native ‘Ankle-Biter’ Aedes Mosquitoes

From CBS Los Angeles
October 2, 2020

SANTA ANA (CBSLA) – Amid an explosion of non-native “ankle-biter” Aedes mosquitos across the Southland this summer and fall, Orange County is trying out a new treatment to combat the insects.

The O.C. Mosquito and Vector Control District Thursday was using an A1 Super Duty larvicide sprayer to spray out a mist with an organic bacteria at Fairhaven Cemetery in Santa Ana.

“What we are doing tonight is a wide area larvicide spraying,” Heather Hyland with OCMVC told CBSLA Thursday.

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West Nile Virus cases reported in Tulare County

From FOX 26 News
October 1, 2020

The Tulare County Health & Human Services Agency announced five human cases of West Nile Virus have been reported in Tulare County.

Two cases are confirmed to have contracted the virus and three cases are probable.

Public health officials urge residents to take precautions against mosquito bites, as mosquito samples positive for West Nile Virus have been detected in multiple locations within the county.

In addition, samples indicate that St. Louis Encephalitis Virus (SLEV) may also be present, posing a risk to the public.

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Aedes aegypti mosquitoes found across Ventura County. Here’s what we know.

From the Ventura County Star
October 1, 2020

After emerging for the first time in Ventura County less than a month ago, potentially dangerous Aedes aegypti mosquitoes have now been found in east and west Ventura, Fillmore, Westlake Village, Piru, Thousand Oaks and Simi Valley, officials said Thursday.

Unconfirmed reports of the mosquito have also come from other communities, including Camarillo and Santa Paula.

“We expect to get more reports from all areas of the county,” said Cary Svoboda, program lead for Ventura County Environmental Health Division’s vector control program. “They’re just very good at moving around and getting their foot in the door.”

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County detects West Nile virus in dead bird for first time this year

From The Almanac
September 30, 2020

San Mateo County’s Mosquito and Vector Control District has detected West Nile virus in a dead bird for the first time this year.

The bird — an American crow — was collected in South San Francisco earlier this week, the vector control district said Wednesday.

It is the first case of the virus found in San Mateo County since 2018. Though reports of dead birds indicate presence of the virus, the risk to humans remains low.

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Zika-carrying mosquito species found in Davis

From FOX 40
September 30, 2020

DAVIS, Calif. (KTXL) — The mosquito responsible for the spread of the Zika virus has broken out of a containment zone in Winters and has been found in a neighborhood in Davis.

The Sacramento-Yolo Mosquito and Vector Control District aggressively went after the Aedes aegypti mosquito in 2019, an invasive insect that’s known to carry the Zika virus and several other exotic diseases.

The discovery of the mosquito in Sacramento County was the first time the insect had appeared this far north.

In 2016, a Zika outbreak in the United States caused bitten pregnant women to have an increased risk of their babies being born with deformities and permanent neurological damage.

In mid-August, a major infestation in the Yolo County town of Winters drew lots of attention from mosquito technicians.

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Adult Mosquito Control to take place in Discovery Bay

From The Press
September 30, 2020

Due to the high abundance of mosquitoes in the area, the Contra Costa Mosquito & Vector Control District will be using truck-mounted ultra-low volume sprayers to control adult mosquitoes.

DATE: Thursday, October 1, 2020

TIME: Between dusk (approximately 7:00 p.m.) and 11:00 p.m., weather permitting.

LOCATION: Discovery Bay

The area to be treated is bordered on the north by Willow Lake Road and Marina Road; on the south by Wayfarer Court and Cherry Hills Drive; on the east by Channel Drive; and on the west by Discovery Bay Boulevard.

MATERIALS USED: The insecticide to be used is Zenivex E4 RTU applied at a rate of 1.5 ounces per acre by truck-mounted ultra-low volume sprayers.

MAP: For an interactive map, please click here.

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Pandemic Could Make SoCal’s Mosquito Invasion Even Worse

From NBC Los Angeles
September 30, 2020

Millions of Southern Californians have been under attack–itching and scratching from bites all over their bodies–by what appears to be a record explosion of tiny “ankle-biter” mosquitoes, known as the Aedes breed.

“I have bites on my ears, under my chin, on my breasts, in between my fingers, not just on my ankles,” says LA resident Rosemary Hochschild. “I feel like I’m going to go mad.”

But efforts to control these mosquitoes by LA County’s Vector Control agency have been hampered by the pandemic.

When the pandemic started, Vector Control had to stop performing service calls at residents’ homes. During those calls, Vector Control inspectors will come to your home, tell you where mosquitoes are breeding, and often treat those areas with “larvicide.”

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Day-biting mosquito that can carry Zika virus, yellow fever found again in Yolo County

From the Sacramento Bee
September 30, 2020

The dog days of summer have waned in the Sacramento region, but the dreaded yellow-fever mosquito apparently is still finding places to breed here.

The Sacramento-Yolo Mosquito and Vector Control District reported Tuesday that it had found an adult female aedis aegypti in a new area of Yolo County: a trap at Pioneer Park near El Macero in Davis. On Sept. 15, the same species of mosquito was also found in Winters.

Yellow-fever mosquitoes carry not only the disease for which they are named but also Zika virus, dengue fever and chikungunya. There are no documented cases of mosquitoes transmitting these three illnesses in California.

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91 Human West Nile Virus Cases Reported In California As Officials Encourage Risk Reduction

From CBS Los Angeles
September 30, 2020

LOS ANGELES (CBSLA) — Spreading diseases such as malaria, West Nile and Zika, mosquitoes are among the deadliest animals in the world.

To date, California officials have reported a total of 91 West Nile virus cases in people statewide. Of those, L.A. County Public Health said it has identified 27 local cases.

West Nile virus, according to the Centers for Disease Control and Prevention, is the leading cause of mosquito-borne disease in the continental U.S.

Mosquito season is typically from March to late October or early November, and there are currently no vaccines to prevent or medications to treat the disease in people.

Most people infected with West Nile virus do not feel sick, but one in five people experience a fever and other symptoms, the CDC says.

About one out of 150 infected people develop serious and sometimes deadly reactions to the disease, according to health experts.

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How zika virus degrades essential protein for neurological development via autophagy

From EurekAlert!
September 28, 2020

In a study published in Autophagy, researchers at the University of Maryland (UMD) shed new light on how Zika virus hijacks our own cellular machinery to break down a protein that is essential for neurological development and cellular communication, getting it to “eat itself”. By triggering this process known as autophagy, Zika virus is able to degrade an important protein, a process that may contribute to the development of neurological or brain deficiencies and congenital birth defects in the newborns of infected pregnant women. By understanding the underlying mechanisms of how this process takes place, researchers are coming closer to developing therapeutic interventions to prevent congenital birth defects such as microcephaly caused by Zika virus infection in pregnant mothers.

“The Zika virus is able to disrupt our cellular mechanisms to create a conducive environment to replicate,” explains Yanjin Zhang, associate professor in Veterinary Medicine at UMD. “It upregulates some proteins and downregulates others that have antiviral roles, manipulating and interfering with cells to its own advantage. In this case, it looks like the KPNA2 protein may have some antiviral effects, so the virus uses the natural cellular self-destruction process called autophagy, or self-eating, to get rid of KPNA2.”

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Yolo County reports first human case of West Nile Virus this year

From the Winters Express
September 24, 2020

A Yolo County resident became ill with West Nile Virus last month and is now recovering, the county reported Saturday.

This is the first human case of the mosquito-borne virus documented in the county this year. Statewide, at least 16 counties have reported human West Nile cases, affecting around 60 people. Since 2003, there have been 7,000 confirmed human cases and more than 300 deaths, according to the state.

Yolo County officials did not provide additional details about the local case, including city of residence, but West Nile activity has been found in mosquito samples and dead birds throughout the county, including in the city of Davis.

The virus is transmitted to people via the bite of infected mosquitoes, making mosquito control key to preventing spread of the illness.

Dr. Mary Ann Limbos, the county’s deputy public health officer, said Saturday the county resident diagnosed with West Nile “is now recovering,” but said the risk of contracting West Nile Virus in the county at this time of year remains.

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Aedes Aegypti Mosquito Capable Of Carrying Dengue, Zika Viruses Detected In Thousand Oaks

From CBSLA
September 24, 2020

THOUSAND OAKS (CBSLA) — A non-native mosquito capable of carrying dengue and Zika virus has been detected in Thousand Oaks, the second instance it has been found in Ventura County.

Aedes aegypti mosquitos have been detected in Thousand Oaks, the Ventura County Environmental Health Division said in a news release Wednesday. The first detection of the mosquito was on Sept. 9 in Simi Valley, officials said.

Officials described the Aedes aegypti as a small, aggressive day-biting mosquito that has been spreading in many California communities. It is capable of transmitting viruses like dengue, chikungunya, yellow fever and Zika, but authorities say those viruses are not currently being transmitted in California.

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Invasive Aedes mosquito species found in second Ventura County city

From VC Star
September 23, 2020

Ventura County officials have found specimens of an invasive and potentially dangerous species of mosquito in Thousand Oaks several days after the mosquito’s presence in the county was publicly shared.

Aedes aegypti mosquitoes, also known as yellow fever mosquitoes, were first detected in Simi Valley on Sept. 9, according to the Ventura County Environmental Health Division. The species is identifiable by the white stripes on its back and legs and is able to carry viruses such as Zika, yellow fever, dengue and chikungunya. They are described as small and aggressive day-biting mosquitoes, according to authorities.

Though the species can carry potentially fatal diseases, no known cases of transmission have been recorded in California.

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First-ever ‘Yellow Fever’ mosquito detected in Butte County

From KRCR News
September 23, 2020

For the first time in Butte County the mosquito commonly known as the yellow fever mosquito has been found.

The invasive species was discovered September 17 in northeast Chico in the area of East Avenue and Mariposa Avenue.

The Aedes aegypti mosquito has been detected previously in other areas of California, but never in Butte County. Aedes aegypti have the potential to transmit viruses such as chikungunya, dengue, yellow fever, and Zika, that are not known to be transmitted by Butte County’s native mosquitoes, and to date, have not been detected in Aedes aegypti in California.

“The District is working to evaluate the extent of the infestation and we plan to do everything we can to eradicate this mosquito and to protect our residents from the potential disease risk of these invasive mosquitoes,” said Matt Ball, District Manager. “Our goal is to control and eliminate this species of mosquito so that it does not become established in our community.”

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Invasive Aedes mosquito species found for first time in county, spawning health concerns

From the Ventura County Star
September 21, 2020

A potentially dangerous species of mosquito not found before in Ventura County has emerged in Simi Valley with more people reporting bites every day.

“We are being flooded with calls,” said Ron Ventura, supervisor with the Ventura County Environmental Health Division. “We’re getting a dozen calls a day at least.”

The small black mosquito with white stripes on its back and legs is called Aedes aegypti or yellow fever mosquito. Found in Kern and Los Angeles counties and long suspected of having crossed into Ventura County, the aggressive day-biting insect was found in Simi Valley on Sept. 9 after a resident reported being bitten.

The mosquitoes generate concern because they have the potential to transmit dangerous viruses including Zika, dengue, chikungunya and yellow fever.

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Yolo County health department reports first case of human West Nile Virus in 2020

From the Sacramento Bee
September 19, 2020

Yolo County health officials announced Saturday that a resident of the county contracted West Nile virus last month, the first case of the virus in a human there reported this year.

In a news release, the county’s Health and Human Services Agency said that the person was infected last month and is recovering.

“Although this patient is now recovering, it is important to note that there is a risk of contracting West Nile virus in Yolo County this time of year,” Deputy Public Health Officer Dr. Mary Ann Limbos said in a prepared statement.

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West Nile virus risk in Contra Costa County continues as more birds and sentinel chickens test positive

From The Press
September 19, 2020

The Contra Costa Mosquito & Vector Control District (District) has confirmed two sentinel chickens and three dead birds have tested positive for West Nile Virus (WNV).

Two birds are from Brentwood, one is from Concord. This is the first bird from Concord to test positive for WNV this year. Both chickens are from Holland Tract in East Contra Costa County. These are the first sentinel chickens of the year to test positive for WNV in Contra Costa County.

Certain types of birds may carry WNV. When a mosquito bites an infected bird, the mosquito can become infected and transmit the virus to another bird or a person through a mosquito bite.

Chickens serve as sentinels of WNV transmission in a particular area because when an infected mosquito bites a chicken, the chicken is naturally resistant to WNV and does not get sick. Chickens do, however, develop antibodies that can be detected in lab tests and confirm when they have been exposed to WNV. Due to their antibodies, chickens are an important tool in the District’s Integrated Vector Management (IVM) approach to reducing the risk of WNV.

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Greater Los Angeles Vector Control Has a New Strategy to Slow West Nile Virus

From Spectrum News 1
September 17, 2020

LOS ANGELES — As Americans continue to focus on the Coronavirus, mosquito experts want locals to be cognizant of another virus moving back into Los Angeles: West Nile.

Studies show that a mosquito is the deadliest animal in the world in terms of how many humans it kills every year. 

The Greater Los Angeles Vector Control District (GLAVCD) technicians answer calls for problem areas and educate communities on how to eliminate sources.

Ryan Rothenwander is a GLAVCD specialist who explained how an abandoned driveway full of junk can became the perfect breeding ground for mosquitoes.

“These buckets and containers that, when it rains, water will get stuck inside there, and as it warms up again the mosquitoes lay their eggs on the inside of the container and they start breeding like crazy,” Rothenwander explained.

The house is one of about 50 the Rothenwander consistently checks, in addition to answering calls from residents who can’t find the source of their mosquito problems.

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West Nile Virus: Can Climate Change Cause Mosquito Migration?

From Contagion Live
September 16, 2020

Given the range of West Nile virus and other mosquito-borne diseases is environmentally determined, changes in the environment mean changes in where these diseases are most likely to spread.

West Nile virus spreads most efficiently in the United States at temperatures between 75.2–77 degrees Fahrenheit, according to a new study published in the journal eLife.

The results imply that climate change may lead to the increased spread of West Nile in some places, while causing a decrease in spread elsewhere.

“As the climate warms, it is critical to understand how temperature changes will affect the transmission of mosquito-borne diseases,” said lead author Marta Shocket, who is a Postdoctoral Researcher at the University of California, Los Angeles.

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Invasive mosquitoes found in Winters

From the Daily Democrat
September 16, 2020

The Sacramento-Yolo Mosquito and Vector Control District announced that it has detected the invasive mosquito Aedes aegypti in Yolo County.

According to Luz Marie Robles, public information officer for the district, the adult female mosquito was found in a trap near East and Main street in Winters.

This is the first discovery of invasive mosquitoes for the 2020 season within District boundaries and the first detection ever in Yolo County, Robles reported.

“As part of our ongoing surveillance program, we have been setting traps looking for invasive mosquitoes,” said Gary Goodman, district manager. “Finding this mosquito for the first time likely means it could possibly be established anywhere. We will continue to work diligently to look for and identify locations where these mosquitoes can be breeding.”

 

Two human West Nile virus cases found in Valley

From the Antelope Valley Press
September 16, 2020

LANCASTER — The Los Angeles County Department of Public Health (Public Health) has identified the first two cases of human West Nile virus (WNV) infections in the Antelope Valley for the 2020 season.

“Although the Antelope Valley Mosquito and Vector Control District identifies the presence of West Nile virus every year is some form, this is the time of year when potential human transmission is at the peak”, District Entomologist Karen Mellor said.

West Nile virus continues to be a serious health threat to residents in the Antelope Valley. Residents are encouraged to get rid of items that can hold water and breed mosquitoes inside and outside the home.

The act of eliminating breeding sources around the home is important now more than ever as residents spend a majority of their time at home. We are currently in peak mosquito season in Los Angeles County and residents are also urged to protect themselves from mosquito-borne illnesses by using EPA-registered mosquito repellent products.

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Day-biting mosquito that can carry Zika, other viruses found for first time in Yolo County

From the Sacramento Bee
September 15, 2020

Authorities on Tuesday announced the first ever detection in Yolo County of an invasive mosquito that prefers to bite people during the day and has the potential to transmit serious diseases, including Zika.

The adult female Aedes aegypti mosquito, more commonly known as a yellow fever mosquito, was found in a trap near East and Main streets in Winters, according to a news release from the Sacramento-Yolo Mosquito and Vector Control District. Officials planned to set up additional traps in surrounding neighborhoods to help assess the spread of the infestation.

“Finding this mosquito for the first time likely means it could possibly be established anywhere,” District Manager Gary Goodman said in the news release. “We will continue to work diligently to look for and identify locations where these mosquitoes can be breeding.”

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San Mateo County Mosquito and Vector Control District hires new manager

From The Daily Journal
September 15, 2020

The San Mateo County Mosquito and Vector Control District will have a new district manager as Brian Weber is slated to take over for Dr. Chindi Peavey, who is retiring after five years.

The district’s Board of Directors voted for the selection in August. Weber, the assistant manager for the past seven years, will take over Oct. 1.

“Brian has worked closely with all the staff to support and deliver excellent service to the public,” Board of Trustees President Kati Martin said in a statement. “The board looks forward to a bright future working with Brian.”

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More mosquitoes test positive for West Nile Virus in Contra Costa County

From The Press
September 11, 2020

The Contra Costa Mosquito & Vector Control District (District) has confirmed three more groups of mosquitoes have tested positive for West Nile virus (WNV) in Contra Costa County. Two groups of mosquitoes were trapped in Brentwood and one group was collected in Discovery Bay. The positive mosquitoes from Brentwood were collected during District surveillance following last week’s Adult Mosquito Control efforts in Brentwood. Preliminary results suggest the treatment appears to have been effective, but the risk of WNV remains.

So far this year, a total of 11 groups of mosquitoes have tested positive for WNV in Contra Costa County. In past years, the District has confirmed WNV in mosquitoes well into October, so it’s important for county residents to remember, Labor Day is not the unofficial end of WNV season.

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City Warns About the Seasonal Return of Aedes Mosquitoes

From Pasadena Now
September 10, 2020

Fall is a great time to enjoy outdoor space but beware: Aedes mosquitoes are most active during this time.

The notorious ankle-biting, black-and-white striped mosquitoes don’t go away when summer fades. Instead, they continue to pester humans well into October.

The San Gabriel Valley Mosquito & Vector Control District is reminding residents to wear repellent to avoid being bitten. Use any of the following CDC-recommended active ingredients found on a repellent bottle: Oil of lemon eucalyptus, picaridin, DEET, or IR3535.

In addition, according to the city’s in-house news magazine In Focus, take time to clear out any dense vegetation around the home. Dense vegetation in the form of ivy, hedges, and large bushes can provide resting sites for mosquitoes.

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West Nile reported in Orange County

From the Event-NewsEnterprise
September 10, 2020

Have you seen more mosquitoes than usual in Orange County this year? It is 2020, after all. Mosquito and Vector Control District officials have found the first sample of mosquitoes infected with West Nile Virus in Costa Mesa, prompting another warning Wednesday to residents to help with the battle against the pests by tipping out stagnant water around their homes and using insect repellent.

The sample of mosquitoes was collected Aug. 27 from Fairview Park in Costa Mesa and the batch tested positive for the virus on Friday, said Heather Hyland of the Orange County Mosquito and Vector Control District.
Two Orange County residents, including a child, have been infected with the virus so far this season, Hyland said.

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More dengue fever and less malaria – mosquito control strategies may need to shift as Africa heats up

From The Conversation
September 9, 2020

As it becomes too warm for comfort, the Anopheles mosquitoes that transmit malaria may lose the battle against climate change in Africa. But a new foe is on the horizon.

When temperatures are too hot for malaria parasites and the Anopheles mosquitoes that transmit them, conditions may be just right for a different mosquito called Aedes aegypti to thrive. This new mosquito brings the threat of many viruses that it carries.

I have been working on vector-borne diseases, including malaria and multiple arthropod-borne viral diseases, for over 20 years. A new paper by Erin Mordecai and colleagues published in Lancet Planetary Health presents an intriguing look into the future where hot temperatures caused by global warming make much of Africa inhospitable for malaria but other mosquito-borne diseases become widespread.

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West Nile virus found in Tehama County sentinel chicken

From the Red Bluff Daily News
September 7, 2020

RED BLUFF — A sentinel chicken in Tehama County has been confirmed to have West Nile virus, according to a press release from the Tehama County Health Services Agency and Mosquito and Vector Control District.

The diagnosis was confirmed by the California Department of Public Health Vector-Borne Disease Section lab in Sacramento, the release said. Sentinel chickens have their blood checked to detect the presence of West Nile virus and do not develop symptoms.

It is important for county residents to take measures to reduce the risk of contracting the virus. Late-spring rains have caused standing water, which is a breeding source for mosquitoes, the release said. Hot temperatures are a contributing factor to the increasing numbers of mosquitoes breeding, which then increases the risk of virus transmission to humans.

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UC Berkeley researchers receive grant to study mosquito-borne viruses

From the Daily Californian
September 7, 2020

The National Institute of Allergy and Infectious Diseases, or NIAID, granted nearly $8 million to UC Berkeley School of Public Health researchers Eva Harris and Josefina Coloma to study mosquito-borne viruses and pandemic preparedness in Asia and the Americas.

With the funds, which will be distributed over the next five years, Harris and Coloma will establish the American and Asian Centers for Arbovirus Research and Enhanced Surveillance, or A2CARES, on campus. Arboviruses are a class of viruses that are spread by mosquitoes and other arthropods — Zika, dengue and chikungunya are all caused by mosquito-borne arboviruses and will be studied further by Harris and Coloma, according to Harris.

A2CARES will be part of the Centers for Research in Emerging Infectious Diseases, or CREID, consortium that includes several institutions in the United States and one in France, according to the CREID website. CREID will have research centers around the world, including Ecuador, Sri Lanka and Congo.

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Study identifies how infection by Zika virus during pregnancy can affect the fetal brain

From EurekAlert
September 3, 2020

Zika virus infection during pregnancy can cause severe abnormalities in the fetus, including malformations such as microcephaly. In a small proportion of cases, the disease may lead to miscarriage and perinatal death. A network of more than 30 Brazilian researchers set out to find the causes of these problems with the support of FAPESP and obtained important results after half a decade of hard work. A paper describing their findings has been published in the journal Science Signaling.

“We show for the first time what happens in the fetal brain affected by congenital Zika syndrome [CZS],” Helder Nakaya, who is the last author of the paper, told Agência FAPESP. Nakaya is a bioinformatics specialist, a professor at the University of São Paulo’s School of Pharmaceutical Sciences (FCF-USP), and a senior scientist at the Center for Research on Inflammatory Diseases (CRID), which is one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP.

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West Nile Virus Found Near Lake Forest

From the Lake Forest Patch
September 3, 2020

LAKE FOREST, CA — Have you seen more mosquitoes than usual in Orange County this year? It is 2020, after all. Mosquito and Vector Control District officials have found the first sample of mosquitoes infected with West Nile Virus in Costa Mesa, prompting another warning Wednesday to residents to help with the battle against the pests by tipping out stagnant water around their homes and using insect repellent.

The sample of mosquitoes was collected Aug. 27 from Fairview Park in Costa Mesa and the batch tested positive for the virus on Friday, said Heather Hyland of the Orange County Mosquito and Vector Control District.

Two Orange County residents, including a child, have been infected with the virus so far this season, Hyland said. The infections occurred in Anaheim and Huntington Beach.

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Central San Joaquin Valley man dies from Saint Louis Encephalitis virus, officials say

From The Fresno Bee
September 3, 2020

A Madera County man in his 90s died in August from the Saint Louis Encephalitis virus, the county health department reported Thursday.

The county said it is the first confirmed case of SLEV in California this year and the first in Madera County since 1976.

The health department, through preliminary testing, thought it was the West Nile virus before the test confirmed it was SLEV.

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West Nile Virus: Mosquitoes Found Near Los Alamitos

From the Los Alamitos Patch
September 2, 2020

LOS ALAMITOS, CA — Have you seen more mosquitoes than usual in Orange County this year? It is 2020, after all. Mosquito and Vector Control District officials have found the first sample of mosquitoes infected with West Nile Virus in Costa Mesa, prompting another warning Wednesday to residents to help with the battle against the pests by tipping out stagnant water around their homes and using insect repellent.

The sample of mosquitoes was collected Aug. 27 from Fairview Park in Costa Mesa and the batch tested positive for the virus on Friday, said Heather Hyland of the Orange County Mosquito and Vector Control District.

Two Orange County residents, including a child, have been infected with the virus so far this season, Hyland said.

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More mosquitoes test positive for WNV

From the Antelope Valley Press
September 1, 2020

PALMDALE —  Mosquitoes collected from various mosquito traps in Palmdale have tested positive for West Nile virus (WNV). The traps were located near 6th Street East and Avenue R, 20th Street East and Avenue S, and 25th St. East and Avenue R-6.

“So far we have sent in 92 mosquito samples this year, nine of which have been positive for West Nile virus”, District Entomologist Karen Mellor said. “At this time last year, we had five West Nile virus positive samples that were all in Lancaster.”

Mosquito control is a shared responsibility between the District and the residents. Keeping the mosquito population low will reduce the chances of disease transmission and the entire community will benefit from less mosquitoes.

West Nile virus is an endemic in the Antelope Valley. This means that it is regularly found in the Antelope Valley every mosquito season. 

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LA residents encouraged to avoid mosquito-borne threat of West Nile virus

From the Daily Bruin
August 31, 2020

Los Angeles County residents should take precautions against a disease spread by mosquitoes, the Los Angeles County Department of Public Health said.

West Nile virus, a virus transmitted to humans by a mosquito bite from an infected mosquito, can invade the central nervous system and be deadly. Symptoms of infection vary from mild fever and rashes to paralysis and coma. People and animals are susceptible to the virus.

There has been one WNV-related death and five cases of WNV this year in LA County, according to the LACDPH. 35 people have contracted WNV in California, according to the California Department of Public Health. Last year, there were 29 cases and 3 deaths in LA County.

Less than 1% of people infected with WNV have severe symptoms, while about 10% of people with severe symptoms die, said Paul Allyn, an infectious disease specialist at the Ronald Reagan UCLA Medical Center.

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Chino mosquitoes test positive for West Nile Virus

From Champion Newspapers
August 29, 2020

The West Valley Mosquito and Vector Control District detected the presence of West Nile Virus in a collection of five mosquitoes trapped near Mountain Avenue and Satterfield Way in Chino on Aug. 18.

It is the first detection of West Nile Virus in the boundaries of the District this year, said community outreach coordinator Brian Reisinger

The District includes Chino, Chino Hills, Montclair, Ontario, Rancho Cucamonga, and Upland.

The virus was found in the native Southern House mosquito, not the aggressively biting Aedes aegypti and Aedes albopictus mosquitoes that are bothering residents.

West Nile Virus can be transmitted to people through the bite of an infected mosquito, he said.

Up to 20 percent of people who become infected will have symptoms that could include body aches, fever, headaches, nausea, and vomiting, according to the California West Nile Virus website.

Eighty percent of infected people develop no symptoms.

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Higher risk for West Nile virus in Brentwood after more dead birds, mosquitoes test positive

From KRON4
August 29, 2020

BRENTWOOD, Calif. (BCN) – More birds and trapped mosquitoes testing positive for West Nile virus were found recently in Contra Costa County and vector control officials say there’s currently an elevated risk for the virus in the city of Brentwood.

Five of six dead birds testing positive were picked up in Brentwood, the Contra Costa Mosquito and Vector Control District said Friday. The remaining bird was found in Antioch.

In addition, six groups of mosquitoes testing positive were found in Palm Tract near Knightsen, Discovery Bay, and Brentwood.

Although the risk is higher for Brentwood, the virus isn’t restricted to that area, according to Steve Schutz, the district’s scientific program manager.

“Residents countywide should be taking precautions against mosquito bites,” said Schutz. “We appreciate members of the public reporting dead birds – this helps our agency identify where the virus hot spots may exist.”

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First human West Nile virus cases in Merced County traced to the City of Merced

From the Merced Sun-Star
August 28, 2020

Merced County’s first confirmed human West Nile virus infections of the year were traced to the City of Merced, according to Merced County Mosquito Abatement District news release.

The two infected individuals, both women aged 60-80, likely contracted the disease in mid-August, according to the Merced County Department of Public Health.

As of Aug. 21, human West Nile virus cases tally 27 in California. The disease is most typically transmitted to humans through the bite of an infected mosquito.

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‘Ankle-biter’ mosquito now a permanent resident of Kern

From Bakersfield.com
August 28, 2020

One benefit Bakersfield has long enjoyed — a benefit millions of Americans do not have — has been the ability to take a walk on a spring or summer evening, or sip a drink on an unprotected porch, without being “eaten up” by swarms of mosquitoes.

Residents who have moved here from places like New Hampshire or Florida, Louisiana or Georgia, are thrilled to learn they have more freedom to be outdoors in arid Kern County.

But recent changes to the mosquito population in the southern San Joaquin Valley could force residents to get serious about spraying on mosquito repellant along with their perfume or aftershave.

“The Aedes aegypti mosquito is also known as the yellow fever mosquito,” Kern Mosquito and Vector Control District spokesman Terry Knight said at a news conference held Thursday at the district headquarters.

“It’s nickname is the ankle-biter.”

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