Vector Disease


2017 Mosquito-Borne Disease Year in Review

Posted by The VDCI Team on Feb 13, 2018 4:36:30 PM

Written By The VDCI Team


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. 
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Topics: Public Education, Mosquito-Borne Diseases

Mosquito Surveillance – Part 2: Life at the Lab Identifying Species and Disease Testing

Posted by The VDCI Team on Nov 29, 2017 11:28:53 AM

Written By Michael “Doc” Weissmann, Ph.D., Chief Entomologist

As discussed in a previous Mosquito Surveillance blog post, a well-designed surveillance program provides important information necessary to guide a modern mosquito control program. However, trapping the mosquitoes is only the first step in surveillance. Once the mosquito specimens are collected, they must be processed in the laboratory.

lab-mosquito-identification-250x166.jpgOnce the sample is euthanized, the mosquitoes are counted to determine how many were captured. If the trap count is very high, the numbers are estimated and only a sample is identified. How high is high? In locations without mosquito control and with good sources of water, nectar, blood-meals, and harborage, trap counts in the tens of thousands of mosquitoes in one night have been recorded, and not just in the tropics!
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Topics: Integrated Mosquito Management (IMM), Surveillance and Disease Monitoring

Mosquito Surveillance – Part 1: The Art of Hunting Mosquitoes

Posted by The VDCI Team on Oct 30, 2017 2:17:22 PM

Written By Michael “Doc” Weissmann, Ph.D., Chief Entomologist

I may be biased, but in my opinion surveillance is the most critical component of the Integrated Pest Management method of controlling insect pests. In modern mosquito control programs, surveillance includes setting traps to monitor adult mosquito populations in a given area.

harvey-emergency-response-truck-surveillance-250x166-blog_TX-danm.jpgA good surveillance strategy includes choosing the right kind(s) of traps to use that meet the goals of the control program. For example, most female mosquitoes are attracted to carbon-dioxide given off by a breathing animal that would be a potential source for a blood-meal. A CObaited light trap utilizes dry ice or some other source of carbon-dioxide to mimic the breathing of an animal blood source, with a small light bulb to draw the mosquitoes close enough to the trap fan for capture. Egg-laying females of species that live as larvae in smaller, water-filled containers can be collected with Gravid Traps. These consist of a fan and net suspended above a container of “highly organic” water as bait (usually an infusion of fermented hay and other ingredients). Many mosquito species are attracted to light, and a New Jersey light trap draws them into a fan using a bright light as bait, but with the unfortunate side-effect of collecting many other species of flies, beetles, and moths that also come to lights – in some locations at certain times of year it can be quite a chore to pick through the non-mosquitoes that are also collected. Surveys for Aedes aegypti - the primary vector of Yellow Fever, Chikungunya, Dengue, Zika, and other viruses – and the related Asian Tiger mosquito (Ae. albopictus) often utilize BG Sentinel traps and lethal ovitraps to attract egg-laying females of these “container-breeding” species.
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Topics: Integrated Mosquito Management (IMM), Surveillance and Disease Monitoring

The Mosquito Life Cycle: Is It Possible To Control All Stages Of Development?

Posted by The VDCI Team on Sep 20, 2017 11:42:38 AM

Written By Rob Kozar, Front Range Regional Director

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 to 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 mosquito 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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Topics: Integrated Mosquito Management (IMM), Public Education

Getting Smart With Technology: GIS and Mosquito Management

Posted by The VDCI Team on Jul 27, 2017 12:45:06 PM

Written By Deborah Bennett, GIS Specialist

A geographic information system, GIS, is a set of tools that allow us to visualize, question, analyze, and interpret data. By creating maps, reports, or charts, you can reveal relationships, patterns, or trends in data that often play a significant role in decision making.

technician-gis-data-gps-edwin-wilkinson-250x144_dallas-TX-jasonwGIS is designed to capture data and store it in various digital formats (individual files, databases, geodatabases, etc.) so that data can be edited and managed with ease. Most industries and businesses of all sizes can benefit from GIS to improve record keeping, provide guidance on where to apply financial and human resources, and support communication and education efforts with employees and customers. The technology offers a variety of data to assist in decision making, which is vital within industries that manage time-sensitive projects and/or services where public education and public health is a concern.
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Topics: Integrated Mosquito Management (IMM), Technology

Aerial Mosquito Management: Timing Control Efforts

Posted by The VDCI Team on Jul 3, 2017 12:17:38 PM

Written By Robbie Allen, Aviation Science

For districts, counties, or municipalities, it can feel that when the mosquito season starts, the clock also starts. It won't be long before residents begin to contact local leaders to help reduce mosquito populations in their community. If a threat becomes too great, often aerial applications are conducted. The Mission: To reduce large nuisance populations and kill as many mosquitoes that could carry vector-borne diseases as possible. Timing during this mission is a top concern.

2500-acres-larvicide-e_laramie-WY-robbiea-250x166.jpgFrom the moment an aerial applicator wakes up in the morning, he or she is timing out the day. Whether larviciding or adulticiding, timing in Aerial Mosquito Control is an extremely critical component. Knowing the amount of time that is required to go through all the protocols, preflight the aircraft, and be able to hit the “spray on” switch at the exact specified time, to ensure a successful mission, can sometimes present its challenges – but must be accomplished.
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Topics: Integrated Mosquito Management (IMM), Aerial Applications

Disease Spreading Tick: Ixodes scapularis [Quick Overview]

Posted by The VDCI Team on Jun 8, 2017 11:16:00 AM

Written By Emily Hibbard, Entomologist and Contract Supervisor

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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Topics: Public Education, Integrated Tick Management (ITM)

Lyme Disease: 3 Reasons It’s on the Rise in the Northeast

Posted by The VDCI Team on May 17, 2017 10:58:10 AM

Written By Emily Hibbard, Entomologist and Contract Supervisor

Warmer weather has arrived, along with new questions and concerns over ticks, Lyme disease, and the large number of U.S. cases reported in the Northeast. 

2015-dot-map-CDC-269568-edited250x193.jpgAccording to the CDC, there are 30,000+ cases of Lyme disease reported each year. Since national Lyme surveillance began, in the early 1990s, the number of annual Lyme cases has increased. Seasonal variations have contributed to what appears to be a northward expansion. These shifts are suspected to be associated with global climate change. Increases in temperature, changes in precipitation patterns, increases in extreme weather, and rising sea levels are capable of influencing the life cycle, distribution, and prevalence of vector-borne diseases by altering habitat availability and reproduction rates. Reasons contributing to the seasonal variability of tick activity and the probable northeast spread of Lyme disease are tick and host habitat range expansion, longer seasons for tick activity, and increased human exposure seasonally.
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Topics: Integrated Tick Management (ITM), Tick-Borne Diseases

Commercial Properties and Outdoor Employees: 4 Mosquito Management Tips

Posted by The VDCI Team on Apr 6, 2017 11:00:02 AM

Written By Kris New, Regional Director

Food Processing Facilities. Steel Mills. Paper Mills. Power Plants.

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.
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Topics: Integrated Mosquito Management (IMM), Public Education

Urban Mosquito Management: Success of Truck-Based Wide-Area Larvicide Application

Posted by The VDCI Team on Mar 23, 2017 10:39:10 AM

Written By Broox Boze, Ph.D.

Cities around the globe continue to learn about new control methods that can protect their growing populations from disease-carrying insects.

ulv-truck-250x255_brooxb.pngThe emergence of Zika virus in the Americas brought to light many of the challenges facing mosquito control programs and abatement districts throughout the world as well as within the United States. Traditional door-to-door interventions for managing urban mosquitoes such as Aedes aegypti (Yellow Fever mosquito) and Aedes albopictus (Asian Tiger mosquito) have put financial stress on many programs and encouraged investigation into novel or alternate application technologies. It can prove challenging to supply enough manpower to turn over every flowerpot, remove garbage, and inspect every clogged gutter in densely populated areas. Residential technicians also find limited access to private commercial and individual properties and are challenged to identify or access the small and cryptic breeding grounds utilized by these invasive urban mosquito species. The new public health threat associated with Zika, combined with management obstacles, have forced new thinking on how to control mosquitoes within densely populated areas.
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Topics: Integrated Mosquito Management (IMM), Technology