Mosquito & Vector News

Utah on Alert After Aedes aegypti Mosquito Carrying Zika Virus Found

From News 18
September 17, 2019

Libby Nance, Mosquito Abatement District Manager of Moab in Utah, is warning residents to drain or dump standing water on their property due to the presence of a new invasive mosquito known as Aedes aegypti, or the “yellow fever mosquito,” which can carry the Zika virus and yellow and dengue fever.

Zika virus is mosquito-borne, primarily transmitted by the bite of an infected mosquito from the Aedes genus, mainly Aedes aegypti, in tropical and subtropical regions. Aedes mosquitoes usually bite during the day, peaking during early morning and late afternoon/evening.

This is the same mosquito that transmits dengue, chikungunya and yellow fever. Zika virus is also transmitted from mother to fetus during pregnancy, through sexual contact, transfusion of blood and blood products, and organ transplantation.

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Clouds of biting mosquitoes’ scattered around Coos County

September 16, 2019

COOS COUNTY, Ore. (KCBY) — Rain showers mixed with warm evenings this September has resulted in clouds of biting mosquitoes scattered around Coos County, particularly noted around Myrtle Point and Coquille, Coos Health & Wellness officials said Friday.

“The nuisance will continue until water temperatures are cold enough to stop eggs and juveniles from emerging from the water as biting mosquitoes,” officials said. “Mosquitoes are a nuisance and can spread disease. As long as evening temperatures stay warm, consider it worth the effort to inspect your yard and dump out water from any containers that can produce mosquitoes such as buckets, flowerpots, bird baths, old tires and even clogged rain gutters.”

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Mosquito activity high in Bakersfield

September 16, 2019

A species of mosquitoes is infesting Kern County and it has already taken over at least 50 neighborhoods. 

That’s according to Gene Abbott, manager at Kern Mosquito and Vector Control. The species, Aedes aegypti, an aggressive, day-biting mosquito, has the potential to spread viruses such as dengue fever, yellow fever, or Zika virus but it has not progressed to that stage yet, Abbott said. But they are impacting people’s quality of life.

About 90 percent of Bakersfield is currently impacted by the mosquitoes, Abbott said. They’ve most recently expanded into Oildale and northwest Bakersfield, he said. 

“Though they’re not carrying any diseases yet, they are a nuisance,” Abbott said. “These are the mosquitoes that interrupt backyard barbecues and birthday parties. They could very well be a concern in the future.”

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Encephalitis virus found in Chino mosquitoes

From Champion Newspapers
September 14, 2019

The West Valley Mosquito and Vector Control District detected the presence of St. Louis Encephalitis (SLE) virus in mosquitoes collected this week near Comet Avenue and Chino-Corona Road in Chino.

“This is the first time since the formation of the district (in 1983) that SLE has been detected in our area,” said district manager Michelle Brown.

SLE has also been detected in the Central Valley, as well as Riverside and Orange counties, she said.

The mosquitoes carrying SLE are not the black and white “Aedes” mosquitoes that have been aggressively biting residents day and night, but the native “Culex” mosquitoes, Dr. Brown said.

SLE is a mosquito-transmitted virus in the “flavivirus family,” which is the same as the West Nile Virus, Dr. Brown said.

Symptoms are similar to West Nile Virus, which include headache, fever, dizziness and nausea.

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Threatening invasive mosquito on its way to Napa County

From the Napa Valley Register
September 14, 2019

Napa County Mosquito Abatement District is cautioning county residents after an invasive mosquito species capable of spreading disease was found in several Northern California counties a little more than a week ago.

The non-native mosquito, Aedes aegypti, also known as the yellow fever mosquito, was first discovered in Southern California in 2013, according to Abatement District General Manager Wes Maffei. It has since steadily spread north through the state.

Maffei said the mosquito can spread disease, namely dengue fever, Chikungunya, Zika virus and yellow fever. Though there has never been a locally acquired case of those diseases in California, the presence of the yellow fever mosquito creates a risk of transmission from residents who were sickened abroad.

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1 person tests positive for West Nile Virus in Merced County

From ABC30
September 13, 2019

FRESNO, Calif. (KFSN) — Merced County has reported its first human case of West Nile Virus infection this year.

The patient is expected to fully recover, officials said.

So far in 2019, there have been 62 confirmed cases of West Nile Virus infection in California.

This summer, mosquitoes carrying the virus have popped up across the Central Valley, and mosquito control districts have been ramping up their efforts.

Authorities encourage people to do their part by clearing standing water from their property to keep mosquitoes from breeding (that includes small containers of water, dishes under potted plants, animal water dishes, etc.).

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Do You Still Need to Worry About Zika?

From Cleveland Clinic Health Essentials
September 12, 2019

While it has primarily faded from mainstream news, Zika is still active in many parts of the world. Even if the mosquito apocalypse that many feared never actually happened, the risk still largely remains for pregnant women and hopeful-to-conceive parents.

Ob/gyn Oluwatosin Goje, MD, discusses what you need to know about Zika.

The Zika threat has decreased, but it’s still there

“Zika is still a threat for some travelers, but there’s been a big decrease over the past two years of reported Zika transmission,” explains Dr. Goje. “Zika is not an epidemic in the U.S., but there are still some countries with active Zika.”

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West Nile Virus Mosquitoes Found In Southern California

From the Canyon News
September 12, 2019

WOODLAND HILLSThe Greater Los Angeles County Vector Control District released information to the public concerning an outbreak of the West Nile Virus in Southern California.

Officials say infected mosquito samples were collected in four new areas: Montebello, Santa Fe Springs, South Whittier, and Woodland Hills. The control district revealed the details to the public to serve as an early warning system in the detection of mosquito-borne viruses that can infect people and animals.

According to Los Angeles’ CVCD, the summer heat can increase West Nile Virus activity and mosquito populations. According to a press release from the LA CVCD, 57 West Nile Virus human cases have been reported in California; four of which were identified by the Los Angeles County Department of Public Health.

The West Nile Virus has no cure and is transmitted to people and animals through the bite of an infected mosquito. One in five people infected with the virus will exhibit symptoms including fever, headache, body aches, nausea, or a skin rash which can last for several days to months. Over 1 in 150 people infected with the virus will require hospitalization.

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The Monterey County Mosquito Abatement District is on a mission to eliminate the pests.

From Monterey County Weekly
September 11, 2019

At first glance, it appears as if Vince Sanchez is looking at a cup of water with a floating clump of dirt inside. It’s only through a microscope that the particles – some 200 eggs – come into focus.

These eggs will hatch within a few days into larvae, wiggly spindles barely large enough to see with the naked eye. They’ll live at the surface of a pool of water for several days, shedding their skin four times before molting and changing into a pupa. It’s here that an insect grows before splitting open the pupa casing, emerging as an adult.

It’s a metamorphosis story, but not for a beautiful animal. It’s the life cycle of a mosquito to adulthood, and adults will eat nectar from flowers. It’s only the females that bite, sucking blood for protein to use for their eggs to repeat the whole cycle again.

In hot Central Valley summers, the whole process, from egg to adult, happens in as little as four days; in Monterey County, it’s generally closer to two weeks. Keeping them cold can slow the process down to two months, so Sanchez – the public education coordinator for the Northern Salinas Valley Mosquito Abatement District – keeps a refrigerator of large Tupperware containers of water, where he’s cooling and slowing the life cycle. The larvae make for good educational props.

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Researchers detect unreported Zika outbreak in Cuba

From the Yale Daily News
September 10, 2019

Using only data collected from travelers to Cuba, researchers at Yale, Scripps Research Institute and Florida Gulf Coast University detected an outbreak of the Zika virus in Cuba in 2017 that had not been previously reported.

In the study, incidence rates of Zika among travelers to Cuba were used to estimate the incidence rates among Cuban locals. After comparing Zika incidence rates in travelers and locals in Puerto Rico, Jamaica, the Dominican Republic and other countries, the researchers were able to use Zika incidence rates of travelers to Cuba to estimate the number of local Zika cases in Cuba.

“While the methods we used have been used before, the combination of methods that we used made this study the first to have reconstructed an outbreak without any data from local sources,” said Nathan Grubaugh, epidemiology professor at the Yale School of Public Health and corresponding author of the study.

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From Action News Now
September 9, 2019

TEHAMA COUNTY, Calif. – The Tehama County Mosquito Vector Control District says two of their test chickens have tested positive for West Nile Virus.

Mike Robinson, assistant manager for vector control says they have three flocks of sentinel chickens, 10 in Corning, 10 in Red Bluff and 10 near Cottonwood.

One of the infected chickens came from the flock in Corning and the other infected chicken came from Red Bluff.

Robinson says this is not a huge indicator that the virus is spreading to humans.

There are no human cases of the West Nile Virus for 2019 in Tehama County, according to the California Department of Public Health.

Robinson says they test their chickens every two weeks by getting a blood sample from each of them.

Robinson says his team does his best to kill mosquitoes by spraying them at dusk time in populated areas of the county.

He also says to be aware of your surroundings when you’re outside.

It only takes a half-inch of standing water for mosquitoes to breed.

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Seen these bugs lately? Here’s where they’re coming from

September 9, 2019

COACHELLA VALLEY, Calif. – Have you noticed an invasion of little, flying, black bugs over the last few weeks? 

Experts say they’re called Charcoal Seed Bugs — and they’re nothing to worry about. 

We’re seeing higher populations than normal due to the high amount of rain seen in the valley this year. The bugs feed on plants and seeds — so more rain means more food for them to eat. 

They don’t bite, but tourists and business owners say they can be a nuisance, swarming storefronts in downtown Palm Springs, swimming pools and even the airport. 

For Bill Lewis, a sales associate at the shop Only in Palm Springs, clearing the seed bugs out has become a daily routine. 

“We have to sweep the store 2-3 times a day because they get stepped on and then their corpses are just everywhere and it’s disgusting,” Lewis said. 

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Summer heat brings increased West Nile Virus concerns to L.A. County

From ABC 7
September 7, 2019

The hot weather is bringing new concerns over West Nile Virus to the Southland.

Eleven additional mosquito samples tested positive for the virus, according to the Greater Los Angeles County Vector Control District. Officials say positive samples were collected in four new areas: Montebello, Santa Fe Springs, South Whittier and Woodland Hills.

There have been 25 positive samples in the area this year.

Some neighborhoods in Anaheim and Buena Park will be sprayed next week after a recent uptick of adult mosquitoes and dead birds with West Nile in those areas.

So far this year, 57 West Nile Virus cases in humans have been reported in California, four of which were identified by the L.A. County Department of Public Health.

Experts say the summer heat can increase virus activity and mosquito population.

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More Mosquito Samples Infected with West Nile Virus Found

September 6, 2019

The Greater Los Angeles County Vector Control District has confirmed 11 additional mosquito samples positive for West Nile virus, bringing the number of positive samples within the district’s service area to 25 this year.

Positive samples were collected in four new areas — Montebello, Santa Fe Springs, South Whittier and Woodland Hills.

So far this year, no West Nile-infected mosquito samples have been discovered in the Santa Clarita Valley.

Mosquito control is a shared responsibility and residents must take an active role in reducing the threat of WNV in their neighborhoods by taking the following steps:

* Eliminate standing water in clogged rain gutters, rain barrels, discarded tires, buckets, watering troughs or anything that holds water for more than a week.
* Ensure that swimming pools, spas, and ponds are properly maintained.
* Change the water in pet dishes, birdbaths and other small containers weekly.
* Request mosquitofish from your local vector control district for placement in ornamental ponds.
* Wear EPA-recommended insect repellent when outdoors where mosquitoes may be present.
* Report neglected (green) swimming pools in your neighborhood to your vector control district.

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West Nile virus found in Tehama County chickens

From the Red Bluff Daily News
September 6, 2019

RED BLUFF — Two cases of West Nile virus were found in chickens in Tehama County, according to a press release issued Friday by the Tehama County Mosquito and Vector Control District.

The California Department of Health Services Vector Borne Disease Section lab in Sacramento confirmed two chickens from Red Bluff, and Corning tested positive for the virus, the release said.

West Nile virus first appeared in Tehama County around 2004, according to Daily News archives. A Tehama County resident died from the virus in 2017.

The virus is transmitted to humans by the bite of an infected mosquito, according to the Centers for Disease Control and Prevention. West Nile can infect other animals such as horses, chickens, birds and squirrels.

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Invasive mosquitoes biting the Chino Valley

From Champion Newspapers
September 6, 2019

Black mosquitoes with distinctive white stripes are biting and bugging residents in the Chino Valley.

They are considered invasive because they can potentially carry diseases such as West Nile Virus, Zika and others, said vector officials.

The “Aedes” mosquitoes were first identified in the boundaries of the West Valley Mosquito and Vector Control District in 2015, and a steady increase in population has been occurring since then, said district manager Michelle Brown.

“This year, we have observed and tracked a significant increase and the phenomenon is occurring throughout southern California,” Dr. Brown said. “The aggressive, day-biting mosquito prefers to blood-feed on human hosts.”

The district includes Chino Hills, Chino, Ontario, Montclair, Upland, Rancho Cucamonga and surrounding county areas.

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Zika May Cause Damage in Adult Brains Too

From Technology Networks
September 6, 2019

Zika virus attracted worldwide attention in recent years due to the devastating consequences of infection for pregnant women and their fetuses, many of which were born with microcephaly and other severe neurological malformations. Although ZIKV infection has historically been associated to relatively mild symptoms, a number of serious neurological complications were described in adult patients during the 2015 outbreak in America. Despite these clinical observations, how ZIKV is toxic to the adult brain and how neurological problems are caused in infected adults have remained unknown.

Researchers led by neuroscientists Sergio T. Ferreira e Claudia Figueiredo and virologist Andrea Da Poian at the Federal University of Rio de Janeiro (Brazil) have now come up with answers to these questions. First, they exposed small fragments of adult human brain tissue to ZIKV isolated from the blood of an infected Brazilian patient. Contrary to the previous belief that ZIKV only infects neuronal progenitor cells or neurons that are still immature in the developing brain, they found that the virus infected and replicated in adult human tissue, producing new viral particles capable of infecting more cells.

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West Nile Virus Mosquito Control Planned For Orange County

From the Orange County, CA Patch
September 5, 2019

ANAHEIM, CA — The Orange County Mosquito and Vector Control District is reporting an increase of West Nile Virus activity in the Cities of Anaheim and Buena Park.

“Recent laboratory test results indicate a significant number of positive WNV mosquito samples in the area between N. Dale Ave and Euclid, south of the 91 freeway to Ball Road,” the vector control district reported.

Investigating dead birds in the area, the OCMVCD determined that a near-epidemic presence of WNV positive mosquito samples increases the risk of residents getting bit by a mosquito capable of transmitting the virus.

“On September 10, 11 and 12, the OCMVCD will conduct ultra-low volume truck-mounted applications to treat for infected adult mosquitoes between the hours of 10 p.m. to 3 a.m. in a 4.5 square mile area containing approximately 8,883 properties in Anaheim and Buena Park,” Orange County Mosquito Vector Control spokesperson said.

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California Horse Tests Positive for West Nile Virus

From The Horse
September 3, 2019

The California Department of Food and Agriculture (CDFA) confirmed on Aug. 28 that an unvaccinated yearling Andalusian stallion presented with clinical signs of West Nile virus (WNV), including ataxia (incoordination), drooling, fever, and lethargy, on Aug. 18. The colt was tested using IgM-capture ELISA. By the confirmation date, the attending veterinarian reported the horse still displayed signs of ataxia but had received supportive care and improved.

This diagnosis marks the first confirmed case of equine West Nile virus in Madera County for 2019 and the fifth statewide, with other affected counties including Fresno, Kern, San Bernardino, and Stanislaus.

Seventy-five percent of the WNV cases confirmed in California are typically reported in August and September, with the first case being reported in late July or early August most years, said Katie Flynn, BVMS, MRCVS, equine staff veterinarian with the CDFA. In 2019 the first case was reported on Aug. 12.

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Two more cases of West Nile virus reported in Kern County, state health officials say

September 3, 2019

BAKERSFIELD, Calif. (KGET) — State health officials said two more human cases of West Nile have been reported in Kern County.

The California Department of Public Health reported the two cases last week, plus one report of a horse testing positive for the virus.

Three human cases of West Nile have been reported in Kern County in 2019.

Overall, California reported nearly 60 cases so far in 2019.

To help prevent the contracting the virus, you can apply mosquito repellent if headed outdoors, especially at night, and avoid mosquitoes and areas infested with them during the day. Wearing long sleeves and pants can help you avoid being bitten as well.

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Newly arrived mosquito breeds take a bite out of summer in San Diego

From the Los Angeles Times
September 3, 2019

Margaret Sohn’s Normal Heights home has a lovely yard — “one of the reasons why I bought this house,” she said — but she hasn’t spent much time there this summer.

“It’s terrible,” Sohn said of the tiny mosquitoes infesting her property. “It’s just miserable.”

For better or — ouch! — worse, this is the new normal. Several years ago, three nonnative mosquito species moved into San Diego County, bringing a whole new twist on this warm-weather nuisance. Compared to your garden variety mosquito, these pests are smaller, quieter and — at least potentially — a greater menace to public health.

Why could they be more dangerous? The most common of the trio, Aedes aegypti, is popularly known as the yellow fever mosquito. Although the invasive mosquito is capable of spreading tropical diseases such as yellow fever, dengue and Zika, Chris Conlan, the county’s supervising vector ecologist, stressed that the region has seen no cases of these dread ailments.

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Officials find West Nile-infected mosquitoes in northeast Solano

From the Daily Republic
September 3, 2019

FAIRFIELD — The Solano County Public Health Division announced that mosquitoes recently trapped in the northeast area of the county, near Davis, were positive for the West Nile virus.

The samples were collected last week by the Solano County Mosquito Abatement District as part of its weekly, countywide trapping program. The mosquitoes are then sent to the University of California, Davis for testing.

“This marks the official start of West Nile virus season in Solano County,” Dr. Christine Wu, deputy health officer for the county, said in a statement released Tuesday. “This is an important reminder for residents to take the necessary precautions to avoid coming in contact with mosquitoes, such as using insect repellent when outside and eliminating standing water where mosquitos can breed.”

Richard Snyder, district manager for the mosquito abatement district, said in a phone interview that the county usually gets its first indicators for the virus in May or June, so this positive test result comes a little later than normal.

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From Placer MVCD
August 29, 2019

ROSEVILLE, Calif., August 29, 2019 – The Placer Mosquito and Vector Control District detected an invasive (non-native) species of mosquito on Wednesday, August 28. The Aedes aegypti, commonly known as the yellow fever mosquito, was found in a residential south Placer County neighborhood east of Auburn Boulevard at Interstate 80. The California Department of Public Health confirmed the invasive species detection.

“Our first step is to follow our invasive species response plan and do everything we can to conduct eradication efforts to protect our residents and public health,” said Joel Buettner, General Manager. “At this point in time, we have detected one female Aedes aegypti mosquito and are trying to determine the full extent of the infestation.”

The District uses a science-based, Integrated Vector Management approach to assess mosquito activity and risk and conduct appropriate mosquito control. The District’s approach for the detected mosquito area is conducting door-to-door property inspections to determine the infestation level. The District is also coordinating with the Sacramento-Yolo Mosquito and Vector Control District on efforts since the mosquito was trapped near the county border.

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Coachella man, Mecca woman treated for West Nile Virus

August 29, 2019

COACHELLA, Calif.- – Riverside County’s first West Nile virus infections of this year were confirmed today by the county Department of Public Health.
According to agency officials, a 65-year-old Mecca woman and a 71-year-old Coachella man were treated in recent weeks. No additional details were provided.
Riverside University Health System Disease Control specialist Barbara Cole said the patients are expected to recover.

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West Nile Virus in neighboring counties, not here yet

From the Red Bluff Daily News
August 29, 2019

RED BLUFF — West Nile Virus cases have been reported in Butte and Shasta counties within the past month, but Tehama County so far has been spared the virus.

Two people in Butte County have been exposed to the virus, according to the Butte County Health Department. Two mosquitoes carrying the virus have recently been found in Shasta County.

The virus appeared in Tehama County as far back as 2004, when it was discovered in a dead crow found near Diamond Park in Red Bluff, according to Daily News archives. A person died from the virus in Tehama County in 2017.

The virus is most commonly spread to people by the bite of an infected mosquito, according to the Centers for Disease Control and Prevention. Besides humans, the virus can infect other animals such as horses, chickens, birds and squirrels.

Nearly 6,800 cases of West Nile Virus have been reported in California from 2003 to 2018, according to Of those cases, only 303 were fatal.

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Mosquitoes that can transmit Zika found in NorCal counties

From KCRA 3
August 29, 2019

Invasive mosquitoes that have the potential to transmit the Zika virus have been found in Northern California.

The Sacramento-Yolo Mosquito and Vector Control District said it found Aedes aegypti mosquitoes in Citrus Heights on Thursday. The mosquitoes were found at a home and in a street storm drain.


The Placer Mosquito and Vector Control District said it has found this species of mosquito as well. One female was located Wednesday in a residential neighborhood in south Placer County east of Auburn Boulevard at Interstate 80, Placer County officials said.

“As a mosquito and vector control, we protect the public by preventing the risk,” said Joel Buettner, general manager for the Placer Mosquito and Vector Control District.

Buettner said there have been no reports in California of a mosquito transmitting the Zika virus to a person.

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Region Sees Increase In West Nile Virus

From the Escalon Times
August 28, 2019

It was a little late in arriving, but West Nile Virus is making its presence known in the Central Valley.

Specifically, there have been a number of ground and a few aerial spraying operations in and around the Escalon area over the past few weeks.

“Overall in San Joaquin County, the last two weeks, we have seen a significant rise in West Nile Virus activity,” said San Joaquin County Mosquito and Vector Control District Public Information Officer Aaron Devencenzi explained.

Around the county, last week, there were 36 positive samples of mosquitoes, collected in traps and six of those positive samples were collected in Escalon.

“There were 63 positive samples the week prior, 14 of those were in Escalon,” Devencenzi added.

A test sample is 50 or less mosquitoes collected in a trap.

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What you need to know about the deadly mosquito-borne illness Eastern equine encephalitis

From ABC News
August 28, 2019

A rare, potentially deadly mosquito-transmitted illness called Eastern equine encephalitishas been reported in at least three states.

There have been four recorded cases in Massachusetts, including one case in which the person died, while there have been three suspected cases in Michigan.

Cases involving animals have been reported in Florida.

In an interview with ABC News, Dr. Todd Ellerin, director of Infectious Diseases and vice chair Department of Medicine at South Shore Health in Massachusetts, explained that EEE “is the most deadly of all the mosquito-born viral brain infections, aka encephalitides.” However, EEE remains very rare and most people who get it never develop symptoms.

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‘Ankle biter’ mosquitoes becoming more common in Orange County

From ABC 7
August 28, 2019

GARDEN GROVE, Calif. (KABC) — Just what Southern California needs – not just more mosquitoes but a different breed of the insect that is sticking around longer.

The Aedes aegypti, more commonly known as the yellow fever mosquito or ankle biter, was first recorded in Orange County in 2015.

Now the invasive pests have been found in 29 of the county’s cities.

Lora Young with the Orange County Mosquito and Vector Control district says the agency is getting many calls for mosquitoes now.

Each bug may only live about a week, but with days heating up, they’re sticking around longer as a whole.

“We are seeing our mosquito season definitely lengthen all the way into October, November as we’re getting warmer temperatures,” Young said.

“They’re also very aggressive day biters so that’s why residents in the county are more impacted by them. They’re feeling the biting pressure of them.”

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14-Year-Old Girl Fighting for Her Life After Contracting EEE, a Rare Mosquito-Borne Illness

August 28, 2019

A 14-year-old girl is critically ill after contracting a rare mosquito-borne disease.

Savannah DeHart, from Kalamazoo, Michigan, was diagnosed with Eastern Equine Encephalitis, or EEE, a virus spread by mosquitos that causes brain infections. Since her diagnosis on Aug. 16, she has lost her ability to communicate and is on a ventilator in the hospital.

Her mother, Kerri Dooley, said that DeHart’s symptoms started as a headache.

“Friday [the 16th], it got to the point where she didn’t want to move,” Dooley told NBC 8.

Speaking ten days after DeHart’s diagnosis, Dooley said that her daughter’s brain functions are limited.

“She just kind of lays there for now,” Dooley said. “Her brain is trying to heal itself, and she can’t do anything until that happens. It’s been, probably the worst time of my life. I watched my daughter almost ‘check out’ … it’s the word we’ve been using right now.”

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County health officials combat infected mosquito pools

August 27, 2019

EL CENTRO, Calif. – In Imperial County, two cases of Saint Louis Encephalitis and one case of West Nile Virus has been confirmed by residents in the Imperial Valley. 

The county also had a resident die this summer, due to West Nile Complications.

The Imperial County Public Health Department is warning residents to stay protected against mosquitoes.

With hunting season starting in California on September 1, county health officials want to make sure to spread the word about mosquito bite prevention.

Mosquito pools in three cities in the county have tested positive for West Nile Virus and Saint Louis Encephalitis. 
To combat mosquitoes in the valley, the public health department needs help from residents.

Health officials said killing the breeding source for these mosquitoes is vital, so they don’t reproduce.

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First Invasive Aedes Mosquitoes Discovered In San Joaquin County

From Caravan News
August 27, 2019

The San Joaquin County Mosquito and Vector Control District (District) has detected Aedes aegypti mosquitoes in Stockton. The first detection was from a sample of mosquitoes collected on August 6, 2019, in the vicinity of Brookside. “Our goal is to control and limit the presence of this invasive mosquito species,” said Ed Lucchesi, Manager of the District. “We are doing everything possible to ensure these mosquitoes do not become established in our communities; however, this type of mosquito can be very difficult to eliminate,” said Lucchesi.

The District is increasing surveillance efforts by placing additional traps used to collect adult mosquitoes and mosquito eggs. Additionally, the District’s staff is conducting door to door inspections of the residential area near the recent Aedes aegypti detection. The boundaries for the inspections are north to March Lane, south to the Diverting Canal, east to I-5, west to the Stockton Deep Water Channel.

Aedes aegypti is not native to California; however, it is a common mosquito in some urban areas of the southeastern United States and Arizona. Recently this species was detected in Stanislaus County. Elsewhere in California, Aedes aegypti have been found in Fresno, Madera, Merced, and San Mateo counties and numerous areas in southern California. Aedes aegypti has the potential to transmit several viruses, including dengue, chikungunya, Zika, and yellow fever. These viruses are not currently transmitted by mosquitoes in California. Aedes aegypti is a small (about ¼ inch) black and white mosquito that bites aggressively during the day. The public can help prevent the spread of these invasive mosquitoes by calling in daytime biting mosquitoes to the District.

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Studying human behavior might help curb mosquito-borne illness

From News Medical Life Sciences
August 27, 2019

Control and prevention of Aedes-transmitted viruses, such as DengueChikungunya, or Zika relies heavily on vector control approaches. Given the effort and cost involved in implementation of vector control, targeting of control measures is highly desirable. However, it is unclear to what extent the effectiveness of highly focal and reactive control measures depends on the commuting and movement patterns of humans.

Now, a team of researchers at the University of Tennessee at Knoxville say that scientists and health officials should not only focus on vector control in curbing mosquito-borne illnesses. Instead, they should also evaluate how humans behave and commute to and from an affected area, including their living habitats.

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Continued West Nile Virus Activity in Shasta County

August 26, 2019

Two more West Nile virus (WNV) positive mosquito samples have been discovered in Shasta County. One of the samples came from a trap located in the Northeast Redding area and the other came from a surveillance trap located in Anderson.

“With temperatures continuing to be high, and adult mosquito populations lingering, the risk from West Nile virus remains a concern. We ask that residents continue to take precautions to prevent mosquito bites when enjoying time outside,” stated Peter Bonkrude, District Manager of the Shasta Mosquito and Vector Control District. In addition, the District is reminding residents to eliminate any potential mosquito sources on their property to help in the reduction of adult mosquitoes.
West Nile virus continues to be present throughout the state, with positive WNv indicators throughout California counties. Due to this increase in WNv transmission, the District has augmented surveillance and treatment of larval and adult mosquitoes in the affected areas.

The Shasta Mosquito and Vector Control District staff urges residents to take
precautions to avoid mosquito bites by implementing the 4 Ds of protection:
• Drain any standing water that may produce mosquitoes, this includes
flowerpots, old tires, and buckets. Some species of mosquitoes can lay their eggs in
very small sources of water, like a bottle cap.
• Defend yourself and your home by using an effective insect repellent and
making sure screens on doors and windows are in good condition.
• Dusk or Dawn, avoid outside activities.
• Dress in long sleeves and pants when mosquitoes are active

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From Action News Now
August 26, 2019

BUTTE COUNTY, Calif. – A second human West Nile Virus infection in Butte County has been confirmed. The infected person is an adult who suffered from a fever-like illness.

As of Aug. 23, 2019, 45 human West Nile Virus infections have been reported in 11 California counties.

West Nile Virus activity is now widespread throughout Butte County. The Butte County Public Health Department and Butte County Mosquito and Vector Control District are urging residents to protect themselves from West Nile Virus by reducing mosquitoes on their property and preventing mosquito bites.

Butte County Mosquito and Vector Control District have confirmed that 31 groups of mosquitoes and 12 sentinel chickens have tested positive with West Nile Virus.

The district is urging residents to drain all unneeded standing water and to report any suspected mosquito-breeding sites.

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First case of human West Nile virus confirmed in Kern County

From Bakersfield Now
August 23, 2019

Kern County confirmed Friday morning its first human case of West Nile virus this year.

According to the California West Nile Virus website, there were 31 new human cases reported this week in the state.

This brings the total to 45 human cases in 11 counties within the state.

Two people have died in connection to the disease including one person in Fresno County.

Most often, West Nile virus is spread by the bite of an infected mosquito.

Mosquitoes are carriers (“vectors”) that become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals when they bite.

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First West Nile Virus death reported in Fresno County this year

From ABC 30
August 22, 2019

FRESNO, Calif. (KFSN) — The Fresno County Department of Public Health has confirmed the first West Nile Virus death in the county this year.

Health officials say another person also tested positive for Saint Louis Encephalitis which is the first reported case in Fresno County.

According to county officials, as of Wednesday, there are 26 positive human cases of West Nile this year, and that number is expected to increase.

At this time, FCDPH is collaborating with Fresno County mosquito abatement districts and the Central California Blood Center to increase awareness about mosquito activity.

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Zika Was Soaring Across Cuba. Few Outside the Country Knew.

From the New York Times
August 22, 2019

A previously unknown outbreak of the Zika virus swept across Cuba in 2017, a year after the global health emergency was declared over, scientists reported on Thursday.

Until now, the Pan American Health Organization had no record of any Zika infection in Cuba in 2017, much less an outbreak. Following inquiries by The New York Times about the new study, published in the journal Cell, officials acknowledged that they had failed to tally 1,384 cases reported by Cuban officials that year.

That figure is a sharp increase over the 187 cases confirmed in 2016 and is “in line with the estimates for 2017 from our own study,” said Kristian Andersen, an infectious disease researcher at Scripps Research Translational Institute in La Jolla, Calif., and a co-author of the new study.

Because most cases of Zika go unconfirmed, Dr. Andersen added, the outbreak actually may have comprised tens of thousands of infections.

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County confirms three more cases of mosquito-borne illness

From the Imperial Valley Press
August 22, 2019

EL CENTRO — Confirmation three weeks ago that mosquitos carrying West Nile virus and Saint Louis encephalitis were found in the county was followed Wednesday with a report from the Imperial County Department of Public Health of two cases of SLE and the county’s second case of WNV this year.

The two cases of SLE are the first human cases of the disease reported statewide this year, the Health Department said. The West Nile case, unlike a case that killed a 74-year-old Bombay Beach resident on July 4, was not fatal.

The department said all three patients live in El Centro, and they are home recuperating.

The two SLE patients were reported to be middle-aged men who were hospitalized in late July with severe headache, fever and nausea, and were diagnosed with viral meningitis, the Health Department said. Fewer details were released about the West Nile case, other than the patient was also male.

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Mosquitoes in Davis test positive for West Nile virus

From the Davis Enterprise
August 22, 2019

West Nile virus has been detected in multiple mosquito samples tested in Davis in the last two weeks.

Those positive samples were found in north, east and south Davis between Aug. 6 and Aug. 20, according to the Sacramento-Yolo Mosquito & Vector Control District.

These are the first positive mosquito samples found in Davis this year, and come two weeks after the district reported the first positive samples in the county, in Winters and Zamora.

Davis locations where West Nile was detected in mosquitoes include Wildhorse near Duchamp Park; near Northstar Park in North Davis; and near Walnut Park in South Davis, according to the city and vector control district.

In response to this week’s findings, the city said ground spraying will continue in parks and open areas as needed in order to reduce mosquito populations and the vector control district will continue to monitor and conduct laboratory surveillance.

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From First Post
August 20, 2019

A deadly beast that might be the size of a speck but poses a threat to more than half the world’s population. This predator, your not so friendly neighbour, is the mosquito that causes so much menace around the world. They are the cause for the spread of many vector-borne diseases such as Dengue, Malaria, Yellow Fever, Chikungunya, Zika, and many more and have caused great losses to humanity.

Even with the progress of science and technology that has taken place, mosquitoes take almost 2.7 million lives every year. In the last 30 years, the worldwide incidence of dengue has risen 30-fold. Additionally, more countries have recently reported the outbreaks of Dengue. While the incidence of diseases caused by Aedes aegyptus mosquito continues to rise; the worldwide cases of Malaria has finally reached a stagnation point with just a slight increase in the last 3 years.

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County Finds More Mosquitos Infected with West Nile Virus

From SCV News
August 19, 2019

The Greater Los Angeles County Vector Control District has confirmed West Nile virus in four additional mosquito samples from traps in the cities of Carson, Northridge, Reseda and Signal Hill.

This follows the discovery of WNV-infected mosquito samples in Bellflower and Long Beach on July 15 and July 10, respectively.

The first two cases of WNV infections in humans were reported Aug. 5.

Residents are urged to use EPA-registered repellents when spending time outdoors to prevent mosquito bites and WNV illness. Not all repellents are effective against mosquitoes but the Centers for Disease Control and Prevention recommends repellents with the following active ingredients: DEET, Picaridin, IR3535 and Oil of Lemon Eucalyptus.

West Nile virus is endemic in Los Angeles County, and the summer heat can increase virus activity and mosquito populations. So far this year, 10 WNV human cases have been reported in California, two of which were identified by the Los Angeles County Department of Public Health. Visit CalSurv Maps for a comprehensive look at this year’s West Nile virus activity throughout Southern California.

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Mosquitos test positive for West Nile virus in Signal Hill, health officials say

From the Long Beach Post News
August 19, 2019

West Nile virus continues to be detected in mosquitos across Los Angeles County, recently showing up in Signal Hill, the Greater Los Angeles County Vector Control District reported today.

West Nile has already been detected this year in Long Beach and Bellflower. Today, the district said signs of the virus have been found in four additional mosquito samples from traps in Carson, Northridge, Reseda and Signal Hill.

Residents are urged to use EPA-registered repellents when spending time outdoors to prevent mosquito bites and West-Nile-related illness.

Not all repellents are effective against mosquitoes but the Centers for Disease Control and Prevention recommends repellents with the following active ingredients: DEET, Picaridin, IR3535 and Oil of Lemon Eucalyptus.

West Nile virus is endemic in Los Angeles County, and the summer heat can increase virus activity and mosquito populations, according to a district statement.

So far this year, 10 human cases of West Nile have been reported in California, two of which were identified by the Los Angeles County Department of Public Health.

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Tustin woman is 1st human case of West Nile virus in Orange County in 2019

From The Orange County Register
August 19, 2019

A female resident of Tustin, in her 50s, is the first human case of West Nile virus reported in Orange County this year, the Orange County Health Care Agency announced Monday, Aug. 19.

Last year, the virus affected 12 people in the county and resulted in one death, according to the Health Care Agency. The first human case reported in 2018 also was a Tustin woman.

On Aug. 5, the Orange County Mosquito and Vector Control District announced that mosquitoes found in Orange, along with nine dead birds discovered in Cypress, Buena Park, Huntington Beach and Tustin, had tested positive for the virus.

Last week, vector control officials said infected mosquitoes also had been found in Buena Park and Santa Ana.

The disease is passed on to humans by infected mosquitoes that contract it from birds.

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Mosquitoes carrying the West Nile Virus are spotted all over the Central Valley​

From the Debate Report
August 18, 2019

Officials of Fresno County in California have announced and warned the locals that mosquitoes infected with the West Nile Virus keep appearing in the Central Valley. Mosquito control districts have increased their attempts to control and exterminate the threat.

The Consolidated Mosquito Abatement Control District has begun making use of spray trucks geared with insecticide to spray the targeted areas all around the valley. The Culex species of mosquito is well-known to carry the West Nile Virus, and it is usually active in the evening and over the course of the night. The officials set for the trucks to spray during that specific time.

As per a collaboration between the California Department of Public Health, UC Davis and the Mosquito and Vector Control Association of California, there have been 319 mosquito samples that were found to be positive for the West Nile Virus in Fresno County thus far this year. The neighboring county, Tulare, has been even worse, having 613 positive tests for the virus until now.

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One-third of toddlers exposed to Zika in the womb suffer developmental problems, study says

From the Daily Herald
August 17, 2019

A new study of toddlers exposed to the Zika virus during their mothers’ pregnancies found that nearly a third suffered developmental delays and other problems — even if they were born without the abnormally small heads and underdeveloped brains often associated with the virus.

The study of more than 200 babies, published recently in the journal Nature Medicine, also shows that a very small number of children born with the congenital condition known as microcephaly had their symptoms improve. Conversely, a very small number of the children born without symptoms of microcephaly went on to develop it.

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West Nile virus now detected in La Verne and Pomona

From the Daily Bulletin
August 15, 2019

West Nile virus activity was detected in a sample of mosquitoes in La Verne and Pomona, the San Gabriel Valley Mosquito and Vector Control District announced Thursday.

The announcement comes 10 days after the announcement of a similar finding in Baldwin Park and Orange.

The vector control district tests female mosquitoes and birds throughout the year for the presence of the virus and other mosquito-borne diseases.

The West Nile virus is the most common mosquito-borne disease that affects Los Angeles County, according to the vector control district website.

Two people were reported to have contracted the virus in late July and are expected to recover, Los Angeles County Public Health officials announced Aug. 5.

Those who contract the virus may experience symptoms such as fever, nausea, mild rashes and body aches. Some may experience more severe neurological symptoms as a result of inflammation in the brain and spinal cord, leading to paralysis, coma or death, according to the vector control district website.

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Mosquitoes drive students indoors

From The Press
August 15, 2019

Last week, the Town of Discovery Bay was swarmed by a scourge of mosquitoes.

Likely hatched in nearby flooded fields, the inland floodwater mosquitoes caused enough trouble to trigger comments on social media pages and forced students at Old River Elementary (ORE) to spend their lunch and recess inside on Wednesday and Thursday.

“The kids (were) getting bit like crazy over here,” said ORE principal Ray Witte. “The kids are having a little bit more reaction to the bites, so we just said we are keeping them inside so they don’t get bit.”

Witte explained that his instructions came from the Knightsen district office, which was in contact with the Contra Costa Mosquito and Vector Control District (CCMVCD).

Nola Woods, public affairs director for CCMVCD said the insects are different than the average bloodsuckers that torment East County, but not dangerous.

“This is a mosquito that is an aggressive biter and it will bite during the day and at dusk,” Woods said. “The key thing about this mosquito is that it is not a known vector of West Nile Virus.”

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Birth defects associated with Zika virus infection may depend on mother’s immune response

From Science Daily
August 14, 2019

New research led by scientists at The Rockefeller University in New York may help explain why Zika virus infection causes birth defects in some children but not others. The study, which will be published August 14 in the Journal of Experimental Medicine, suggests that the risk of developing an abnormally small head (microcephaly) depends on the types of antibody produced by pregnant mothers in response to Zika infection.

The Zika virus is spread by mosquitoes in tropical and subtropical regions, and, in most adults, the symptoms of infection are fairly mild. But the widespread Zika outbreak in Brazil in 2015-2016 revealed that infection during pregnancy can cause a wide range of fetal abnormalities, with microcephaly occurring in around 5% of live births by Zika-infected mothers. “Why some Zika virus-infected pregnant women deliver apparently healthy newborns while others have babies with microcephaly is unknown,” says Davide F. Robbiani, a Research Associate Professor at The Rockefeller University, who co-led the study with Professor Michel C. Nussenzweig.

Various factors have been proposed to increase the risk of microcephaly, including previous exposure to viruses that are similar to Zika, such as dengue virus or West Nile virus. Antibodies generated by the body’s immune system to combat these viruses may recognize the Zika virus but, instead of neutralizing it, help it to enter the mother’s cells and possibly cross the placenta to infect the unborn fetus.

With the help of researchers and physicians in Brazil, Robbiani and colleagues analyzed blood samples collected during the 2015-2016 outbreak from Zika-infected mothers who had given birth to either healthy or microcephalic children.

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From Action News Now
August 13, 2019

BUTTE COUNTY, Calif. – The Butte County Public Health Department has announced the first confirmed human West Nile Virus infection in Butte County.

The infected person is an adult who suffered a fever-like illness.

As of Aug. 9, 2019, 10 human West Nile virus infections have been reported in California, not including the Butte County case. 

The infection is active July through October, with August typically being the peak month in Butte County. 

Health officials want to remind residents of the following tips to avoid contracting the virus:

  • Avoid spending time outside when mosquitoes are active, especially at dusk and dawn
  • If you must be outdoors when mosquitoes are active, wear long pants, and long-sleeved shirts, socks and shoes
  • Before going outdoors, apply insect repellent containing DEET, Picaridin, IR3535 or oil of lemon eucalyptus according to label instructions
  • Make sure that doors and windows have tight-fitting screens. Repair or replace screens that have tears or holes
  • Eliminate all standing water on your property that can support mosquito-breeding
  • Report standing water to Butte County Mosquito and Vector Control District
  • Contact Butte County Mosquito and Vector Control District if there is a significant mosquito problem where you live, work, and/or play

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