While there are more than 3,000 species of mosquitoes in the world, there are fewer than 200 species in the United States. Regardless of the number of species, mosquitoes play a significant role in how American communities and individuals enjoy outdoor activities. To what extent you’ll be affected depends on the climate, desirable habitat, and several other factors and variables unique to your region.
Written by the Vector Disease Control International (VDCI) team
Official reports on vector-borne diseases, severe weather, and changes in our climate were repeated in various media outlets last year. The attention brought heightened awareness to a number of disease-carrying pests, with a lot of the attention on - the mosquito. For this article, we will provide a brief overview of mosquito-borne disease reporting to the Centers for Disease Control and Prevention (CDC) in 2018. We will also discuss lesser known mosquito-borne diseases, and the CDC report that highlighted an increase in vector-borne disease reporting over the last decade.
Vector-borne disease transmission cycles are complex. They involve a variety of interconnected environmental parameters - meaning that predicting where they will be prevalent in any given year is difficult. However, we will also briefly cover what is currently being reported in 2019.
Written by Kelsey Renfro, Ecologist, Taxonomist, and Laboratory Manager in Colorado
Generally, in Colorado, we spend day after day digging through piles of Aedes vexans, Culex pipiens, Culex tarsalis, and several other common species. When it comes to adult mosquito surveillance, our Denver office alone sets and collects over 200 traps per week. It can get pretty exciting while sorting through a pile of mosquitoes, during your normal monotonous routine, when a specimen that doesn’t seem to belong appears under your microscope. After running the unique arthropod through a dichotomous key (an identification tool), the excitement is heightened when you realize you have found a mosquito species never previously recorded in your state! In a single season, our Denver lab identified three (3) species that lacked historical records in the state of Colorado. Needless to say, our team was intrigued by the new discoveries and took on the challenge to monitor their presence during the remainder of the season as well as throughout the next year.
The obvious question was, “Why are new species entering Colorado?” The state has seen a substantial increase in people moving in over the last decade. Could the influx of human residents be playing a role in the introduction of the 6-legged residents? Are changes by Mother Nature contributing to the mosquito species crossing state lines? Or a combination of the above?
Over recent decades many mosquito-borne diseases have resurfaced or emerged and spread rapidly. From Zika, dengue to West Nile fever and chikungunya. Even malaria, which has had long-term global efforts to eradicate it has recently shown signs of increasing.
Many of these diseases have no specific treatment and the limited medicines available for some are facing resistance. Insecticides used to control mosquitoes are also facing resistance. On many fronts, innovations are urgently needed to control old diseases and prevent new ones from spreading.
Scientists in fields as diverse as biochemistry, genomics, entomology, computing, remote sensing, avionics, artificial intelligence, robotics, and aerospace engineering are combining their resources to develop new ways to fight diseases.
Here are a few examples of some recent scientific developments that are bringing a new dawn in the fight against the global threat of 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 malaria, yellow fever, and dengue-hemorrhagic fever. What is the history and what are the current local cases of mosquito-borne disease in the U.S.?
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.
Written By Team VDCI
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?
Written By Rob Kozar, Front Range Regional Director - Colorado
Like cell phones, computers, and domestic beer, today’s adult mosquito fogging trucks bear little resemblance to their predecessors from the not too distant past. While Ultra Low Volume (ULV) fogging machines have been in use for decades the technology to collect data, map, and apply pesticides in the pursuit of controlling adult mosquito populations is as cutting-edge as never before. The utilization of such technology allows mosquito control professionals across the country to practice adult mosquito control via a “science on wheels” approach which places primacy on accuracy, efficacy, and safety as well as the capacity to generate information useful and frequently necessary for clients in addition to helping the employee performing the application.
Written By Kellie Nestrud, Biologist and Contract Manager in Louisiana
There are several different components of a successful Integrated Mosquito Management (IMM) program. The consideration of chemical resistance in the local mosquito population is one of the components. Knowing, understanding, and monitoring for chemical resistance should begin as early as possible in an IMM program. It is recommended that all IMM programs monitor their mosquito populations for resistance at the beginning of a season and as often throughout the season as thought necessary. Resistance data is most valuable when collected over time to allow for comparison and monitoring of trends. There are many methods to monitor the effectiveness of an insecticide, and program managers may need to adjust their approach from season to season.
The Centers for Disease Control and Prevention (CDC) defines that a population of mosquitoes is considered to be resistant to an insecticide if a mortality rate is less than 90%. So how would one know if they are working with a population that has resistance?
Written By The VDCI Team
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.