Public Health: U.S. Mosquito-Borne Diseases

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Deep Dive Into Common Mosquito-Borne Diseases

There are really only two reasons to control mosquitoes; to avoid nuisance biting, and to preclude the spread of mosquito-borne disease. Everyone recognizes that mosquitoes can be a terrible blood feeding nuisance, but many people do not realize the magnitude of the health threat that they represent globally. Some of the world’s most deadly diseases are carried and transmitted by mosquitoes. It is estimated that up to a million people die every year from mosquito-borne illness with many countries around the world ravaged by malariayellow fever, and dengue-hemorrhagic fever. What is the history and what are the current local cases of mosquito-borne disease in the U.S.? 

Malaria: The World's Deadliest Mosquito-Borne Disease has a History in the U.S.

Malaria is a disease caused by a Plasmodium parasite and is the leading cause of mosquito-borne deaths throughout the world. In the past, local malaria cases were reported within the U.S. It wasn’t until after 1950 that malaria was considered eliminated from the country, due to large-scale mosquito control efforts and swamp drainage. While the disease is not currently a threat, one of the primary carriers of the disease parasite in the pre-1950s U.S. – is far from eliminated. Anopheles quadrimaculatus (also known as the Common Malaria Mosquito) is distributed throughout the eastern United States, often occurring in huge numbers in the southeastern states, especially along the Gulf of Mexico. This fact reinforces the importance of robust surveillance and disease testing programs in areas where the species inhabits.

What Mosquito-Borne Diseases are in the U.S.?

In more recent years, West Nile virus, several types of encephalitis, and dog heartworm have been the primary mosquito-borne diseases in the U.S. Additionally, Zika virus, dengue fever, and chikungunya have emerged over the past couple of years as threats to human health in the United States, South America, and the Caribbean.

What is Mosquito-Borne Encephalitis?

Mosquito-borne encephalitis can be a severe result of many viruses vectored by mosquitoes. In the U.S., it is geographically wide-spread and is prevalent in several forms: West Nile virus (WNV), La Crosse encephalitis (LAC), eastern equine encephalitis (EEE), Jamestown Canyon virus (JCV), and several others. Encephalitis is an inflammation of the brain and central nervous system and is characterized by a high to moderate mortality rate, with some survivors left with permanent physical and mental disabilities.

West Nile Virus: #1 Mosquito-Borne Disease Threat in the U.S.

West Nile virus, which in severe cases can cause encephalitis, entered the U.S. along the east coast in 1999 and has had serious ongoing implications for the rest of North America as it has spread across the country. 47 out of 50 states and the District of Columbia reported West Nile virus infections in people, birds, or mosquitoes in 2017.

WNV is typically transmitted to humans by mosquitoes that have previously fed upon an infected bird. While over 150 species of mosquitoes have been known to carry WNV, the primary vector species in the U.S. are Culex pipiensCulex tarsalis, and Culex quinquefasciatus. These mosquitoes are all active at night, and most cases of infection occur during the summer months. Approximately 20% of people affected by WNV will experience flu-like symptoms including fever, headache, nausea, muscle pain, and swollen lymph glands. Other symptoms may include a stiff neck, rash, sleepiness or disorientation. In severe cases, an individual can develop West Nile Encephalitis or Meningitis, which can lead to coma, tremors, convulsions, paralysis, and even death.

2003 was the largest WNV outbreak in the U.S. with 9,862 cases reported and 264 deaths. 2012 was the deadliest year for WNV in the U.S., with 286 deaths reported to the CDC. West Nile virus is a concern in North American bird populations and remains the #1 mosquito-borne disease threat to humans in the U.S., with over 46,000 cases reported between 1999-2016.

Chikungunya: A Human Virus

WNV, EEE, LAC, and a few other mosquito-borne encephalitis viruses have an animal reservoir and cannot be transmitted from human to mosquito. Chikungunya is a human virus. Mosquitoes become infected when they feed on a person already infected with the virus and then spread the virus by feeding on other humans. Because of this ability, the virus has the potential to spread quickly, especially in urban areas with larger populations. The virus first reached the Americas in 2013, with local cases reported in the U.S. in Florida (2014) and Texas (2015).

Dengue Virus: Enjoying Urban Environments

Dengue virus, another human virus, is transmitted by certain Aedes mosquitoes. On a global level, the virus is considered a significant threat as our world’s urban landscapes grow. Beyond the increase in desirable habitats for the container-breeding species, the virus has four strains (multiple serotypes) making it complicated for medical professionals to manage. Chikungunya virus shares similar symptoms to dengue and provides those bitten with immunity from future chikungunya infections. Unfortunately, with multiple strains of dengue, an individual is more likely to be hospitalized or die if infected with more than one serotype. Dengue is considered under reported or misclassified. The World Health Organization posted an update on the virus globally, citing research1 that estimates the real number of dengue infections could be close to 390 million annually.

The United States has experienced local cases of dengue in Florida, Hawaii, and near the Texas-Mexico border. Larger outbreaks have occurred within U.S. Territories, including Puerto Rico, the U.S. Virgin Islands, and U.S.-affiliated Pacific Islands.

Heartworm Disease: Infecting Our Four-Legged Friends

Heartworm Prevention and Dogs

In addition to human cases of mosquito-borne disease, there is a growing concern for pet owners. Dirofilaria immitis, commonly referred to as heartworm, is a parasitic roundworm that infects a variety of mammals. Heartworm is found throughout the world and has been reported in all states in the U.S. The natural host is dogs. Infection in dogs can lead to heartworm disease and, if left untreated, severe physical damage and death may occur. Fortunately, for felines, most worms in cats don’t survive to the adult stage. Prevention is an option, for both dogs and cats, and should be discussed with your veterinarian. Although isolated human infections have been reported, heartworm is not currently recognized as a human health problem.

Mosquitoes Abundant and Problematic

As an individual, if you’ve ever been driven inside by biting mosquitoes or have chased the pesky invaders around the bedroom in the middle of the night, you may consider 1 or 2 mosquitoes – too many. When mosquitoes become abundant and problematic, there becomes an even greater need for control efforts. Hurricanes, such as Harvey and Irma in 2017, have the ability to create vast areas of standing water that produce extreme mosquito populations and make the already difficult disaster relief efforts even harder and more dangerous. With or without a natural disaster, economic losses can be considerable for businesses or travel destinations that are considered uninhabitable or unsuitable due to unmanaged environments creating large populations of one of nature’s deadliest and least popular creatures – the mosquito.

1 Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL et.al. The global distribution and burden of dengue. Nature;496:504-507.

Contact Us to Learn More About Effective Mosquito Prevention Strategies:

VDCI_Logo_square Since 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective mosquito control programs. We are determined to protect the public health of the communities in which we operate. Our mosquito control professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated mosquito management program, from surveillance to disease testing to aerial application in emergency situations.

Vector-Borne Disease Spotlight: Jamestown Canyon Virus

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Exploring the Impact of Mosquito-Borne Diseases

What? There is another virus that can be transmitted by mosquitoes?! Yes. Mosquitoes are the deadliest animals in the world, and Jamestown Canyon virus is another virus on the long list of diseases vectored by these arthropods.

What is interesting about Jamestown Canyon virus (JCV), is that it behaves a little differently than a few of the viruses the public may be more familiar with. West Nile virus (WNV) and Zika virus rely on a reservoir host to perpetuate the virus, as the mosquito cannot pass it on to their offspring. With JCV, in addition to having reservoir hosts, such as deer, this virus can also have transovarian transmission, which means the parent arthropod (in this case a mosquito) can pass the disease pathogen to their offspring. This is not completely uncommon. Rocky Mountain spotted fever is a vector-borne disease that is transmitted through an infected tick carrying the bacterium Rickettsia rickettsii. The bacterium can be transmitted to offspring in this way as well.

JCV was first discovered in Culiseta mosquitoes in Jamestown, Colorado, in 1961. Since 1961, it has been found in various mosquito species (AedesCulexCoquillettidia), mammals, and humans across North America.

Aedes_aegypti_Adult_Mosquitoes

Is Jamestown Canyon Virus Common?

Jamestown Canyon virus is an orthobunyavirus of the California serogroup. This is the same group that was mentioned in the news last month when it was discovered that a boy in Florida had been infected with the Keystone virus, another mosquito-borne disease, that hadn’t previously been found in humans. JCV was not considered a nationally notifiable disease until a few years back, and states are not mandated to report to the CDC. Depending on local data collection, staff reporting, and even local municipal funding it’s often hard to find a clear picture of disease incidence rates. Only 9 cases of JCV, in the U.S., have been recognized by the CDC, from 2000 to 2012. In 2013, testing for the JCV antibody began at the CDC, and the number of human cases reported increased to 22 in one year! From 2014 to 2016, between 11 to 15 cases were reported each year; however, JVC is likely endemic through most of the United States. It is thought to be under-recognized in the U.S. and Canada because most cases are asymptomatic (showing no symptoms). The lack of awareness can be concerning for individuals who may be more susceptible to the disease, such as the young, elderly, and those with a compromised immune system.

*Data points obtained from www.cdc.gov

How Are Individuals Affected by Jamestown Canyon Virus?

JCV is transmitted during the summer by a few different mosquito species within the United States and Canada. As far as the severity of the disease goes, about 68% of reported cases to the CDC have been considered neuroinvasive (capable of infecting the nervous system). That is a little higher than WNV but lower than La Crosse encephalitis or Eastern equine encephalitis (EEE). The disease onset time and symptoms are similar to that of WNV. A person might develop a sore throat, rash, fever, vomiting, and/or nausea 2 days to 2 weeks after being bitten. Just like many other arboviruses, JCV can cause meningitis or meningoencephalitis. At this time, along with other arboviral diseases, there is no treatment for JCV.

A wife in New Hampshire watched her husband battle unknown health complications, and he ultimately passed from encephalitis in June of 2018. A month prior to his death, test results showed evidence of Jamestown Canyon virus and his family wonders if the virus was the leading contributor. With so many unknowns and the medical community still learning about the virus, additional research and education continue on JCV.

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Can You Avoid Jamestown Canyon Virus Transmission?

It is important to become familiar with symptoms of vector-borne diseases that have been documented in your region, especially for individuals who work or spend a lot of recreational time outdoors when vectors are active. The best way to keep from contracting mosquito-borne disease is local vector management measures and personal protection efforts. So what CAN people do to protect themselves from mosquito bites, and contracting Jamestown Canyon virus? It sounds simple and obvious, but avoid being bitten.

When outside during dusk or dawn, try to wear loose-fitting, long-sleeve, light-colored clothing. Also, use an EPA-approved mosquito repellent on exposed skin. When you are in your yard, take a look around at items that can hold water. Mosquitoes will lay eggs in a receptacle as small as a plastic bottle cap. Inspect tires, gardening items, sporting equipment, bird baths, clogged gutters, and low areas in your yard. An area or object that can hold water for more than 4 days can be a potential breeding site for mosquitoes.

Community leaders and mosquito management professionals continue to research and implement efforts to protect public health – but everyone can play a role. By practicing source reduction on your property to prevent larval habitats and taking personal protection measures to prevent mosquito bites, you are aiding in the reduction of mosquito populations and reducing the risk of mosquito-borne disease.

Contact Us to Learn More About Effective Mosquito Prevention Strategies:

VDCI_Logo_square Since 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective mosquito control programs. We are determined to protect the public health of the communities in which we operate. Our mosquito control professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated mosquito management program, from surveillance to disease testing to aerial application in emergency situations.

Mosquito Control Services: Integrated Management Matters

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Integrated Mosquito Management (IMM) is a term that everyone in the field of public health mosquito and vector-borne disease control is familiar with. The American Mosquito Control Association (AMCA) defines IMM as, “a comprehensive mosquito prevention and control strategy that utilizes all available mosquito control methods, either singly or in combination, to exploit the known vulnerabilities of mosquitoes to reduce their numbers while maintaining a quality environment.” This definition describes what Integrated Mosquito Management is, but why is IMM the best practice for controlling mosquitoes and mosquito-borne diseases?

What is Integrated Mosquito Management? Watch to Learn More!

As the definition states, the goal of any IMM program is the reduction of mosquito populations through the use of environmentally sound methods. As such, the best way to achieve this goal is through the combined use of whichever strategies and tactics are available for each individual IMM program. Because of the great variety of mosquito species and habitats, mosquito-borne diseases, local nuisance tolerances, program budgets, and pesticide use preferences throughout the world, it is important that each individual IMM program has the flexibility to use the combination of methods that will best accomplish their specific mosquito control needs. An effective Integrated Mosquito Management program will use some combination of the following principles to accomplish its specific goals:

  1. Larval and Adult Mosquito Surveillance (including disease testing)
  2. Source Reduction and Physical Control through Habitat Manipulation
  3. Larval Mosquito Control
  4. Adult Mosquito Control (including efficacy and pesticide resistance testing)
  5. Public Education and Outreach

Species and Habitat Diversity

With more than 3,000 mosquito species in the world, and over 175 in the United States alone, it is easy to understand why integrating these principles and practices is important to the success of a mosquito abatement program. Different mosquito species have different preferences for everything from larval habitat to host species to peak activity period. Therefore, there is not an effective single strategy for controlling all species across all geographies. By using scientific information about the local mosquito species’ preferences, managers can decide which principles and practices will provide the best control of the mosquitoes in their particular area.

Mosquito-Borne Diseases

Mosquito-borne diseases, such as malariaWest Nile virusZika virus, and Heartworm disease, are a major concern for public health professionals because these diseases cause widespread illness in both people and animals, as well as hundreds of thousands of deaths, every year. Once again, different mosquito species cause different problems because they can transmit different diseases. As such, designing and implementing an IMM program that utilizes the most effective tactics to control the specific species that carry the specific diseases of concern in an area is the best way to help reduce their transmission to both people and animals.

Local Nuisance Tolerance

The local tolerance for nuisance mosquitoes is also an important consideration when determining what IMM principles should be integrated into a mosquito control program. Some residents may not want to see a single mosquito in their neighborhood all summer, while other people are either less bothered by biting mosquitoes or live in an area where it is simply not possible to eliminate them all. IMM program managers must then decide which mosquito control strategies and tactics will allow them to create an environment acceptable to local residents. While it’s often not possible to please everyone, choosing the best combination of IMM principles to integrate into their program will yield the best results and satisfy the most people.

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Budget Limitations

For most IMM programs the ultimate goal is a practical reduction of the local mosquito populations based upon their budget. Quite often, designing a program that integrates as many of the primary IMM principles as possible is limited by the available financial resources. While a larger budget will usually allow for the integration of more components into a successful IMM program, the strategic use of less expensive practices can still yield good results and provide an effective IMM program. Surveillance and public education, for example, are some of the less expensive components of an IMM program, and, depending upon the circumstances, they can provide both information about mosquito populations and disease threats. In addition, public education can protect residents by teaching them about personal protection measures. This can include how to reduce mosquito habitat around their homes and reduce the risk of being bitten by proactively using repellents, wearing proper clothing, and avoiding peak mosquito activity periods.

Environmental Impact

Finally, one of the primary goals of Integrated Mosquito Management is maintaining a healthy ecosystem. Everyone who works in mosquito and vector control understands the need to minimize any environmental impacts of our programs. By intelligently integrating as many of the principles and practices as possible into a responsible IMM program, any possible negative impacts on the environment will be greatly reduced or even eliminated.

These are just some examples of why Integrated Mosquito Management is the preferred strategy for operating a mosquito and mosquito-borne disease abatement program. By using a well-considered combination of scientifically based, environmentally sound principles and practices, mosquito control managers can tailor their management programs to fit the specific needs in their community and gain the best possible reduction in the local mosquito populations.

VDCI is committed to public education and spreading awareness throughout the U.S. about the dangers of mosquito-borne diseases and their preventability, with the overarching goal of reducing illness and fatality statistics in 2018. Our dedicated and experienced team works tirelessly to prevent the spread of mosquito-borne diseases in all of the contracts we service. If you would like more information about any aspect of an Integrated Mosquito Management (IMM) Plan, including mosquito surveillancedisease testingadult control, or aerial applications, please contact Vector Disease Control International (VDCI), and we will help you get started immediately.

Contact Us to Learn More About Effective Mosquito Prevention Strategies:

Government Partners in Mosquito ManagementSince 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, military bases, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective integrated tick and mosquito management. We are determined to protect the public health of the communities in which we operate. Our tick and mosquito management professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated tick and mosquito management program, from surveillance to disease testing to mosquito aerial application in emergency response  situations.

Industry Partnerships: Opportunities to Learn and Grow

Meeting with Leaders In Mosquito Management

The 84th Annual Meeting of the American Mosquito Control Association (AMCA) took place in Kansas City, MO. The Association’s president, Wayne Gale, brought attention to the meeting’s ability to bring together the industry to share experiences, discoveries, and challenges. A portion of AMCA’s mission highlights the goal to, “… provide leadership, information and education leading to the enhancement of health and quality of life through the suppression of mosquitoes.…”

VDCI is incredibly proud of the way our team continues to reinforce AMCA’s mission, with their dedication to expanding their knowledge of mosquito management by partnering with experts across the industry. It brings us joy to share a few examples, of collaboration and supporting the future of mosquito control, that were discussed or were on display during the 2018 Annual Meeting.

Environmental Conditions and Mosquito-Borne Disease

birds and road-b-658054-edited.jpegDr. Broox Boze prepared a poster presentation focusing on the role of birds and climate change in predicting West Nile virus outbreaks in Northern Colorado. This collaborative project was funded by the National Center for Atmospheric Research and highlights the important role of drought and other environmental factors affecting environmental and human health.

West Nile Virus Detection

One of the week’s symposiums offered insight into the use of Loop-Mediated Isothermal Amplification (LAMP) in Arbovirus Detection (a group of viruses that are transmitted by mosquitoes, ticks, or other arthropods). Two of the symposium presentations included collaborative work with the Centers for Disease Control (CDC) and Dr. Daniel Markowski, VDCI’s VP of Operations. The research used a novel assay to detect West Nile virus in mosquito pools as part of a county public health mosquito management program in Ohio. Along with a team from the CDC, the surveillance and disease monitoring efforts were supported by VDCI’s Regional Director, Cristina Flores and Contract Manager, Theodore Green.

Resistance Monitoring in the Delta

20180228_135431-219546-edited.jpgRegional Director, Kris New and Contract Managers, Kellie Nestrud and Mi’Shayla Johnson, alongside Dr. Boze, completed work on insecticide resistance monitoring in both Mississippi and Louisiana. Playing an active role in understanding the mosquito species in a given area, and what control efforts are most meaningful, is a subject our team takes seriously. The group’s role was a piece of a larger research project lead by the CDC. VDCI’s efforts were recognized in both oral and poster presentations by colleagues at the CDC. The poster that focused on the evaluation of Culex quinquefasciatus in Louisiana received the 2nd place award (Great work, Milena!).

Emergency Response Perspective

panel-2-576396-edited.jpgThe moment that mosquito control is elevated to an Emergency Response mission, public health leaders at the local, state, and federal level call on service contractors and chemical suppliers as well as the military to support response needs. The panel discussion From Chaos to Calm: Mosquito Control Response to Hurricanes Harvey, Irma, and Maria was comprised of seven individuals providing perspectives from each of the areas mentioned. VDCI’s Dr. Daniel Markowski discussed how our team prepared and executed mosquito response plans on the ground and in the air – stressing the importance of maintaining clear channels of communication with public health leaders, suppliers, and local officials throughout each mission. Responding to large-scale mosquito outbreaks is never easy. However, with the combined efforts of our partners in the industry, we were able to mobilize our staff and give residents and first responders in each state relief from the billions of mosquitoes that resulted from the floodwaters. According to Dr. Markowski, “This was VDCI’s 12th hurricane event that we’ve responded to. In every one, you realize that the team we have makes the long days and insane work hours bearable.” VDCI is proud to help the people in Texas and Florida, but hope they never see hurricanes on this scale again.

AMCA Young Professionals (YP)

amca-yp-2018-david-theuret-250x152.jpgWhether as a professional or a student, the AMCA YP group welcomes individuals starting their career (less than 5 years) in the mosquito industry. Along with several other organizations, VDCI enjoys sponsoring an individual to attend the Annual Meeting and partake in the week-long agenda the association creates specifically for the YPs. With VDCI headquarters located in Little Rock, AR – it was exciting to learn our 2018 YP was also our neighbor!

David Theuret is beginning his career as a Public Health Entomologist for the Arkansas Department of Health. Mr. Theuret provided a recap of his time at AMCA saying, “The 2018 AMCA meeting was an amazing experience. Partnering with VDCI through the Industry Shadowing Program allowed me to take full advantage of all of the opportunities to learn and network at this meeting, and I am grateful for their support. The research presented provided a clear sense of direction for future projects to improve the program in Arkansas; including emergency vector control response following natural disasters, innovative methods of community outreach, and invasion of new mosquito species such as Culex coronator. Networking with experts and speaking with my fellow young professionals was wonderful, both personally and professionally. They have reinvigorated my excitement about continuing to work and grow in this field, and I can’t wait to see everyone next year!”

Supporting the Future

20180226_133646-986327-edited.jpgThe YP Association held an auction during the Annual Meeting. The activity was an exciting way to raise funds for future YP programs, and Dr. Broox Boze was happy to support the auction by donating a stained-glass mosquito masterpiece. What began as a creative hobby in high school has found its way into many chapters of the scientist’s life. Thank you to Dr. Boze and the winner of her art! Both of your contributions have supported the future leaders in our industry.

As a result of this year’s meeting, the VDCI Team is actively working on ideas, challenges, and partnerships to aid in the ongoing mission to protect public health. We remain vigilant in our efforts, and look forward to the listening and participating at the 2019 meeting in Orlando, Florida. We hope to see all of our friends and partners there!

Contact Us to Learn More About Effective Mosquito Management Strategies:

VDCI_Logo_square Since 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective mosquito control programs. We are determined to protect the public health of the communities in which we operate. Our mosquito control professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated mosquito management program, from surveillance to disease testing to aerial application in emergency situations.

2017 Mosquito-Borne Disease Year in Review

Exploring Mosquito-Borne Diseases In the U.S.

In 2017, the scientific community, the public, and the press maintained their interest in the Zika virus outbreak of 2016. Articles surfaced on the potential long-term health complications attributed to contracting the virus. The public received extra education on personal protective measures to reduce the spread of Zika. And the scientific community reviewed trusted and experimental methods to prevent future outbreaks.
 
In addition to Mother Nature bringing new mosquito-related problems to Texas and Florida last year, in the floodwaters left by Hurricanes Harvey and Irma, both states reported the only locally-acquired U.S. cases of Zika virus for the second year in a row. 
There were several mosquito-borne diseases reported in the United States in 2017. In this blog, we will focus on: West Nile Virus (WNV), Eastern equine encephalitis (EEE), and Zika. WNV remains the most common virus transmitted by mosquitoes to humans in the U.S. as well as responsible for taking the highest number of human lives.

All of the data points in this post were obtained from the Center for Disease Control (CDC)’s website as of 02/13/2018.

West Nile Virus (WNV)

west-nile-virus-wnv-2017-incidence-cdc-map-united-states-01092018-200x127.jpg47 out of 50 states and the District of Columbia have reported West Nile virus infections in people, birds, or mosquitoes in 2017. Overall, 2,002 cases of WNV were reported in humans, and there were 121 (6%) confirmed deaths in 2017. While this data shows a decrease in the number of human cases reported in 2016 (2,149), it also brings attention to the increase in lives lost, when compared to the 106 (5%) confirmed deaths in 2016. The states reporting the highest number of WNV disease cases* in 2017 include:

California: 509 cases, 28 deaths
Texas: 133 cases, 5 deaths
Arizona: 109 cases, 8 deaths
Illinois: 87 cases, 5 deaths
South Dakota: 73 cases, 4 deaths
 

Georgia did not report as many WNV cases (47) as several other areas of the country; however, the state reported one of the highest numbers (7) of confirmed lives lost as a result of the virus.

*Numbers combine Neuroinvasive Disease Cases and Non-neuroinvasive Disease Cases

WNV is typically transmitted to humans by mosquitoes that have previously fed upon an infected bird. While over 150 species of mosquitoes have been known to carry WNV, the main vector species in the U.S. are Culex pipiens, Culex tarsalis, and Culex quinquefasciatus. These mosquitoes are all active at night, and most cases of infection occur during the summer months. Approximately 20% of people affected by WNV will experience flu-like symptoms including fever, headache, nausea, muscle pain, and swollen lymph glands. Other symptoms may include a stiff neck, rash, sleepiness or disorientation. Less than 1% of those infected will develop West Nile Encephalitis or Meningitis, which can lead to coma, tremors, convulsions, paralysis, and even death.

To learn more about the symptoms, treatment, and mosquito species that vector this virus, visit our educational page on West Nile virus.

Eastern Equine Encephalitis (EEE)

eee-eastern-equine-encephalitis-virus-cases-by-state-2007–2016_cdc-arbonet-400x232.jpgEastern equine encephalitis, also referred to as EEE or Triple E, is a rare but deadly illness for humans. Thankfully, only a few human cases of EEE are reported in the U.S. each year. The CDC sites that an average of 7 cases of EEE were reported annually in the U.S. from 2007 – 2016. In 2016, there were 7 reported human cases of EEE and 3 of those cases were fatal. As of January 9, 2018, there were 3 human cases of EEE reported to the CDC in 2017.

The reason EEE is less common in humans is that the primary mosquito vector (Culiseta melanura), does not typically feed on humans. It is believed that EEE virus is mainly transmitted to humans and horses by bridge vectors that have contracted the virus by feeding on infected birds. Symptoms typically occur four to ten days after a bite from an infected mosquito and include fever, headache, vomiting, muscle aches, joint pain, and fatigue. In rare cases, infection occurs in the brain and spinal cord leading to sudden high fever, stiff neck, disorientation, seizures, and coma. The mortality rate of those that develop EEE is about 33%, the highest among human arboviruses (a virus transmitted by arthropod vectors) cases reported in the U.S. The disease is also a concern for horses. There is a vaccine available for horses, and horse owners are encouraged to discuss an on-going vaccination schedule with their veterinarians. Currently, there is no human vaccine for EEE.

To learn more about the symptoms, treatment, and mosquito species that vector this virus, visit our educational page on EEE virus.

Zika Virus (ZIKV)

Zika_PDF_ButtonIn 2017, within the United States, there were 4 ZIKV cases of local mosquito-borne transmission, 5 cases acquired via sexual transmission, and 409 travel-associated cases reported to the CDC. The 4 local cases were from Florida (2) and Texas (2), the same states that reported the only local cases in 2016 (Florida: 218 and Texas: 6).

U.S. Territories reported a total of 636 local cases in 2017, a dramatic decrease from the previous year. In 2016, U.S. Territories reported close to 36,000 cases of Zika virus that were likely acquired through local mosquito-borne transmission. VDCI partnered with the CDC in several U.S. territories in 2016 to help combat the spread of Zika virus.

Many individuals learned about Zika during the outbreaks in South and North America; however, the virus was first discovered in 1947 in the Zika Forest of Uganda. In the Americas, it has only been linked to transmission by Aedes aegypti or the Yellow Fever mosquitoAe. aegypti is also responsible for the transmission of dengue virusyellow fever virus, and chikungunya virus. In Africa, the virus was detected in Aedes albopictus or the Asian tiger mosquito; hence, it is possible that Ae. albopictus could vector the virus in the Americas.

When symptoms occur, they typically begin with a mild headache and fever. Within a day or two, a maculopapular rash may appear and can cover many parts of the body. Following the rash, people generally report continued fever, malaise, and body aches. Other symptoms can include diarrhea, constipation, abdominal pain, and dizziness. Treatment for symptoms includes hydration, rest, and the use of acetaminophen to relieve fever. If a pregnant woman is infected with Zika virus, it may result in microcephaly, a birth defect causing underdevelopment of the head and brain in newborn children. Currently, there is no vaccine or cure for ZIKV.

To learn more about the symptoms, treatment, and mosquito species that vector this virus, visit our educational page on Zika virus.

Contact Us to Learn More About Effective Mosquito Prevention Strategies:

VDCI_Logo_square Since 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective mosquito control programs. We are determined to protect the public health of the communities in which we operate. Our mosquito control professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated mosquito management program, from surveillance to disease testing to aerial application in emergency situations.

Is It Possible To Control All Stages Of Development?

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Managing Mosquitoes Throughout All Life Stages

As is generally known there are four life stages in the development of a mosquito: egg, larva, pupa, and adult. Perhaps less known is that each stage has a corresponding and unique method of attack, or as we shall see, a lack of one when it comes to targeting mosquito management efforts at each stage of the mosquito’s life cycle.

Life Cycle Stage 1: Egg

1200px-Culex_mosquito_life_cycle_nol_text.svg-067754-edited.pngAlthough several studies have shown the efficacy of several plant-derived botanical oils as an ovicide (an insecticide designed to kill eggs) these studies were conducted in the lab under a carefully controlled environment, very much unlike the conditions found out in the field where mosquitoes eggs are extremely difficult if not outright impossible to identify in the numbers needed to make a meaningful impact. While oviciding could be viewed as an ideal control method, in theory, oviciding remains perpetually unproven in the real world. Because the method remains unproven, mosquito management professionals often consider the next stage of development the best option in mosquito control efforts.

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Disease Spreading Tick: Ixodes scapularis

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Integrated Tick Management

Have you heard several tick-related stories recently? Listened to predictions that we will see an increase in tick populations? Read an article on why we may be seeing a rise in Lyme disease? Watched a story about a new case of Powassan virus? A lot of information has surfaced on ticks in the last few year. While there are hundreds of species of ticks, there is one main culprit in spreading both of the above diseases to humans.

Female_Adult_Black-legged_deer_tick_Ixodes_scapularis_disease_testing-682083-edited.jpgIxodes scapularis, the black-legged tick or deer tick, is the main vector of Lyme disease and Powassan virus to humans. Black-legged ticks are born disease free, and it is during their first larval stage blood meal that the tick may acquire a disease from an infected host. White-footed mice and other small mammals are known in the Lyme disease cycle as the primary reservoir hosts carrying the disease and infecting the larval tick.

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Commercial Properties and Outdoor Employees: 4 Mosquito Management Tips

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Create Safe, Mosquito-Free Spaces

Commercial properties have many facilities that feed, power, and clothe the world. Often these locations are operational 24 hours a day, 365 days a year, and can present employees with challenging working conditions indoors and outdoors. Mosquitoes do not have to be one of the daily challenges on commercial properties. By taking a few simple steps, employers can reduce concern for these pests both as a nuisance and their potential to spread vector-borne diseases.

1. Remove Standing Water

Mosquitoes can breed in the smallest amounts of water, and it does not take much time for an adequate larval habitat to produce the next generation of mosquitoes. To help reduce the chances of mosquitoes breeding on your property, look around for items that can hold water. Tire piles, culverts, ditches or rain gutters that may not drain properly, and low areas in grassy locations are just a few examples of where you may consider checking. If they can be emptied or removed, this is the best way to ensure they do not produce mosquitoes. While ditches may need to be dug out, or a gutter may need to be cleaned, this small amount of effort can go a long way to combat your existing or potential mosquito problem. In some instances, where the water source cannot be removed, it may be beneficial to investigate biological control agents or apply larvicides.

2. Barrier Treatments

Most mosquitoes prefer to rest during the day and come out at dusk in search of a blood meal. They find out-of-the-way places such as storm drains, shrubs, or under walkways and awnings to avoid the elements while they wait for the perfect time to attack! Several of these areas can be ideal to consider a residual pesticide to kill any mosquitoes that utilize the locations to hide on your property. You can apply a treatment with a simple pump sprayer, or, for bigger areas, you may need a powered backpack or truck-mounted sprayer. Most of the time, if the product is applied in a location that does not receive direct sunlight or have an opportunity to be washed away by rain, the treatment can provide your property with a few weeks of control.

3. Personal Repellant

Public Education in Reducing Mosquito Populations 2 bugspray mosquito prevention health and safetyIf you have employees that work outdoors at dusk or dawn, you may have thought about which mosquito repellents are best at protecting your team from this nuisance and potentially disease-carrying pest. DEET, Picaridin, and IR3535 are all approved repellants and come in a variety of forms. You can distribute single-use repellent wipes to carry around a job site or offer spray cans. Be sure to check the chosen product’s label for the concentration of the active ingredient. Providing your employees with education on the product, instructions for application, and expected time frame of protection will ensure maximum efficacy.

 

4. Adult Mosquito Control

Even with all of the above efforts, you may still see some mosquitoes flying on your property. ULV fogging may be necessary to kill mosquito species that are active while your employees are working. If portions of your property are located in hard to reach places, several handheld sprayers can provide an option for crews to complete applications on foot and have a few set flow rates to make the application process easy. Remember to take care applying pesticides around working employees, and always read the product label and associated labeling prior to use. Additionally, be sure to research if the selected pesticide requires an applicator’s license.

VDCI is committed to public education and spreading awareness throughout the U.S. about the dangers of mosquito-borne diseases and their preventability, with the overarching goal of reducing illness and fatality statistics. Our dedicated and experienced team works tirelessly to prevent the spread of mosquito-borne diseases in all of the contracts we service. If you would like more information about any aspect of an Integrated Mosquito Management (IMM) program, including mosquito surveillance, disease testing, or adult control, please contact Vector Disease Control International (VDCI), and we will help you get started immediately.

Contact Us to Learn More About Effective Mosquito Prevention Strategies:

VDCI_Logo_squareSince 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective mosquito control programs. We are determined to protect the public health of the communities in which we operate. Our mosquito control professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated mosquito management program, from surveillance to disease testing to aerial application in emergency situations.

Mosquito Surveillance Traps: Are They All The Same?

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Exploring the Types of Mosquito Traps and How They Collect Data

Why are there several different types of mosquito surveillance traps? This blog will provide a brief overview of seven mosquito surveillance tools, each with its advantages, depending upon what specific information is desired. Adult mosquito surveillance programs include the weekly trapping of adult mosquitoes by dividing an area such as a city, county, or industrial facility into control zones and utilizing traps that are most meaningful in each zone. Understanding a community’s environment and history, along with the implementation of the right trap(s), will provide a better picture of the mosquito species in a given area and if a potential disease threat exists.

CDC Light Trap

CDC light traps are an industry standard in adult mosquito surveillance. Developed by the Center for Disease Control (CDC) and Prevention, these portable traps are powered by a 6V battery with a motorized fan and a mosquito collection cup. CDC traps are portable and can be utilized in a variety of ways, but the most common model is accompanied by a small light and a carbon dioxide (CO2) bait source. The flow of CO2 emanating from the trap will lure adult mosquitoes by simulating the exhaled respiratory gasses of birds or mammals. Mosquitoes attracted to the trap are drawn in at the top and forced downward by the fan into the collection net where they cannot escape. Many mosquito species are active during the evening, and therefore CDC traps are typically deployed at dusk and collected after dawn the following day. The live-trapped mosquitoes can then be analyzed at the lab.

BG-Sentinel Trap

The BG-Sentinel trap was designed with two specific mosquito species in mind, Aedes albopictus (Asian Tiger mosquito) and Aedes aegypti (Yellow Fever mosquito). The two species are known to vector dengue, chikungunya, Zika, and yellow fever viruses and thrive in urban environments. Both species use natural and artificial containers for breeding, making them notoriously difficult to catch in significant numbers. The BG-Sentinel trap is made of a tarp like material, about the size of a 5-gallon bucket, and utilizes an attractant such as Octenol lure, human scent lure, or carbon dioxide (CO2). A funnel located at the top of the trap leads mosquitoes to an electric fan (outlet or battery powered) that pulls them into a collection net. The BG-Sentinel traps do well at catching the elusive Aedes species when placed in the proper areas and with the appropriate attractants.

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Answers To 7 Questions You Asked About

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Common Questions About Mosquito Management

VDCI team members are constantly in conversations with city, county, and parish officials as well as mosquito abatement districts who are interested in starting or upgrading their mosquito abatement programs. We field many questions, and some are really great! We would like to take the time to provide answers to a few of the questions that our professionals were asked over the past year.

1. Our community has conducted our own spraying for years. Why would we want to contract out our mosquito abatement program?

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Mosquito control involves much more than using trucks to spray a community at night. Truck spraying should be the end result of a fully integrated approach to managing mosquitoes that includes public educationsource reductionsurveillance, larvicidingdisease testing, and adulticiding. VDCI can provide all of the above in a turn-key mosquito abatement program, freeing up your resources and lowering your liability.

2. I am aware that VDCI has airplanes. We have never conducted an aerial mission before. Why would we need it?

Aerial missions may not be a need in your community. Many mosquito control operations around the country use aerial applications, and for a good reason. With truck and foot missions, you can encounter limitations with road networks and the ability to safely access a given area. If some areas are not accessible, it can be challenging to ensure good control. VDCI’s aircraft are equipped with industry-leading technology that assists in desired coverage for large and small target areas, often seeing as much as a 95% reduction in the mosquito population.

3. Does truck spraying really work?

Yes, truck spraying is a meaningful and effective action within an Integrated Mosquito Management (IMM) program; however, there are a multitude of factors that need to be taken into consideration for maximum efficacy, such as:

  • Calibration – Equipment MUST be properly calibrated to ensure that you are applying enough product to be effective, while at the same time not over applying and harming non-targets or beneficial insects.
  • Timing/Biology – Most adulticides are designed to kill the flying mosquito. If the mosquito species you are targeting is not active at the time you are spraying, you may as well leave the truck in the shed! Spraying at 4:30 pm may cut down on overtime; however, it does not kill many mosquitoes.
  • Wind Speed and Direction – We rely on our product floating in the air and need a little wind to carry the adulticide through the target area. If there is NO wind, your effectiveness will be reduced, and the product will not move far from the truck. On the flip side, high winds (over 10 mph) will carry the product too fast through the desired area.
  • Droplet Size – If product drops are too big, they will fall out of the air too soon and never reach a mosquito. A large drop can also lead to deposition onto plants and other foliage, potentially leading to non-target exposure, and can lead to pesticide resistance in the future. If they are too small, they may not be lethal enough to kill the mosquito and can lead to resistance within the population.
  • Truck Speed – Driving too fast causes sub-lethal doses to be applied, while driving too slow can put out too much product, affecting non-targets. As a stand-alone option, truck fogging is not the best choice; however, when combined with surveillance, disease monitoring, source reduction, larval control, and public education, truck spraying absolutely has its place in a mosquito management program and can play a huge role in the suppression of mosquito-borne disease.

4. What Effect Does Spraying Have On Other “Beneficial” Insects, Pets, And Humans?

Extensive studies have shown little or no effect on beneficial insects from ULV spraying for adult mosquitoes. By A) limiting applications to areas with documented high annoyance or threat of disease, B) utilizing specialized Ultra-Low Volume technology (applications at approximately 1.0 ounce per acre, with specifically-sized microscopic droplets of a low toxicity product), and C) timing applications only during the evening when mosquitoes are at their peak activity period, and most other non-target insects are not active, we are able to minimize non-target effects. As far as pets and humans are concerned, ULV technology again allows us to apply a very small amount of a very low toxicity product over a large area, which means the amount of product people are exposed to is minimal. Additionally, these products breakdown very rapidly in the environment and do not bio-accumulate. For more information, please visit our Pesticides Page.

5. Which mosquitoes transmit West Nile virus?

At least 43 species of mosquitoes have been found to transmit West Nile virus in the United States. Many of these infected mosquitoes feed only upon birds, thus contributing to a cycling of the virus among avian populations. Other species feed upon these infected birds and then will feed on humans, making them an ideal vector. In urban settings, Culex pipiens and Culex quinquefasciatus tend to be the primary vectors of concern. In rural areas, particularly in the western part of the United States, Culex tarsalis is the primary transmitter.

6. Do really cold winters mean that we will have fewer mosquitoes next year?

Not necessarily. Different mosquito species spend the winter months in different life stages. When the water and air temperature start to get colder, and the days get shorter, mosquitoes will go into a type of hibernation referred to as ‘diapause’. This means adult mosquitoes are not seeking a blood meal, larvae will stay in their current instar stage, and eggs will not hatch even when wet. Anopheles and Culex mosquitoes will overwinter as adults. They find underground storm drains, crawl spaces, barns, and any other place they can get out of the weather and cold. This is why when you get a couple of warm days during the winter, you may start to see a few mosquitoes. There are adult mosquitoes out there simply waiting for it to warm up! Others, such as your Aedes, or floodwater mosquitoes, will overwinter in the egg stage. These eggs can get wet and dry out several times in the winter, but they will not hatch until the spring, when the water temperature warms up and the days start to get longer. So, the short answer is that mosquitoes know how to survive winters and they have been doing it for thousands of years.

7. If we were to go to another city where VDCI works, will there be NO mosquitoes?

You will probably see mosquitoes in areas that VDCI services. VDCI will never claim to decrease your mosquito population by 100%, and you should run from anyone that does make that promise. What you will find is a scientifically-based approach to mosquito control that strives to protect public health by considering all stages of the mosquito life-cycle and each species bionomics. Surveillance alone is not effective. Source reduction or larviciding alone is not effective. Truck spraying alone is certainly not effective. Aerial spraying alone is not effective. What is effective, however, is the combination of all of these components – an Integrated Mosquito Management (IMM) program. An IMM program will reduce the chance of being bitten and contracting a mosquito-borne disease. VDCI continues to use innovative mosquito management methodologies and industry-leading technologies to provide more efficient, cost effective, and timely solutions to protect public health.

Contact Us to Learn More About Effective Mosquito Management Strategies:

VDCI_Logo_squareSince 1992, Vector Disease Control International (VDCI) has taken pride in providing municipalities, mosquito abatement districts, industrial sites, planned communities, homeowners associations, and golf courses with the tools they need to run effective mosquito control programs. We are determined to protect the public health of the communities in which we operate. Our mosquito control professionals have over 100 years of combined experience in the field of public health, specifically vector disease control. We strive to provide the most effective and scientifically sound mosquito surveillance and control programs possible based on an Integrated Mosquito Management approach recommended by the American Mosquito Control Association (AMCA) and Centers for Disease Control and Prevention (CDC). VDCI is the only company in the country that can manage all aspects of an integrated mosquito management program, from surveillance to disease testing to aerial application in emergency situations.