History of the Medical Entomology Program
at the Illinois Natural History Survey
"To provide for research on disease vectors associated with used and waste tires, and the diseases they spread."
Tires and Public Health and Solid Waste Hazards
The introduction and spread across the United States of the invasive Asian tiger mosquito (Aedes albopictus) in the 1980s, primarily through international and national trade of used tires, generated considerable concern among public health officials. The Asian tiger avidly bites humans and it is an important vector of Dengue and Chikungunya viruses. Further, the Asian tiger has been shown to be a competent vector of numerous arboviruses under experimental conditions. Furthermore, waste tires not only transported these exotic mosquitoes around the United States, but they also acted like “incubators” for other nuisance and vector mosquito species, including vectors of LaCrosse encephalitis (Aedes triseriatus, Eastern treehole mosquito) and St. Louis encephalitis (Culex pipiens, the Northern house mosquito). The focus on tires and mosquitoes brought to light a second concern, namely a growing solid waste problem. Tires had been banned from most landfills and occasionally they were associated with fires that were so intense they were simply contained until they burned out. About 13 million used tires are generated annually within Illinois and used tires could be found dumped inside and on the outskirts of most communities or stored in large numbers by tire dealers. The vast number of tires challenged the small tire recycling industry.
Waste Tire Act and the creation of the Medical Entomology program
The Illinois Legislature and the Governor passed the Illinois Waste Tire Act (ILCS 5/53 to 55.7a) in 1989 with the purpose to:
- provide removal of used and waste tire dumps in order to reduce threats to public health
- promote development of recycling facilities and technologies, including energy recovery
- provide grants to local public health districts and mosquito abatement districts in order to conduct mosquito management and pathogen surveillance
- provide for research on vectors associated with used and waste tires and the diseases they spread
Small tire dump in Macon County, IL.
Once vegetation grows over these small dumps of 25-100 tires, they are difficult to locate. The tires tend to hold water for long periods and the water often comes organically rich due to the decaying vegetation. They rapidly become habitats for approximately 15 mosquito species including vector and nuisance species. Several small tire dumps, like the one at the left, were discovered around Decatur in 2002. Soon after that Aedes albopictus was collected in mosquito traps near this area. This mosquito spread throughout the city in 2003 and continues to be detected annually, despite an intense effort to cleanup tire dumps.
The Used Tire Management Fund, which is maintained by a fee from the retail sale of tires, provided the Illinois Department of Natural Resources with a annual budget to be used by the Illinois Natural History Survey to "perform research to study the biology, distribution, population ecology, and biosystematics of tire-breeding arthropods, especially mosquitoes, and the diseases they spread."
In 1990, Illinois Natural History Survey established the Medical Entomology Program to conduct research on mosquito species associated with tires, establish their sensitivity to microbial and synthetic insecticides, evaluate alternative control methods in the laboratory and field, and improve methods for surveillance and monitoring of pathogens and vectors. Over the next 17 years, The Program evolved into a multidisciplinary group of research scientists, technical personnel, students, and hourly academic staff, addressing a broad range of questions regarding the biology and behavior of vector mosquitoes, the transmission and management of mosquito-borne pathogens, and their impact on wildlife.
Invasion of West Nile Virus
Since the 2002 Outbreak of West Nile virus (WNV) in Illinois, a large portion of the Program’s research focused on defining the factors that regulate the intensity of West Nile virus transmission in Illinois. The ability of West Nile virus to overwinter in northern areas resulted in annual outbreaks in Illinois. The Emergency Public Health Fund in 2003 was established under the Waste Tire Act by Public Act 093-0052 and provided an additional source of financial support to the Illinois Natural History Survey in order to expand research, surveillance, and diagnostics for WNV. The Medical Entomology Program assists public agencies throughout the state in their virus and mosquito monitoring. All of the test results are provided to the Illinois Department of Public Health to assist them in making risk assessment.
West Nile virus transmission cycle between birds and mosquitoes
In less than 5 years, West Nile virus (WNV) spread from the Atlantic to Pacific coasts in North America, presumably by a combination of avian and anthropogenic dispersal mechanisms. An unprecedented consequence of this phenomenal range expansion was the establishment of endemic transmission cycles in a mosaic of ecosystems from the tropics of Central America to temperate southern Canada. The primary vectors, hosts, and risk of transmission vary considerably between and within these broad physiographic regions. The human and wildlife consequences of WNV did not become fully evident until its westward progression extended into the Midwestern and Gulf Coast states in 2002 and then into the Great Plains and Mountain states in 2003. Each of those years was successively the largest arbovirus epidemic in North America and the largest WNV outbreak worldwide. The 2002 Outbreak was the largest mosquito-borne outbreak in the US and the largest WNV outbreak worldwide, Illinois stands out as having the highest number of human cases in 2002 and the second highest number in 2005 and a major resurgence in 2006.