Deer Tick

Stop Ticks On People
A Coalition in Partnership with
Families First New York, Inc.

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Research

Ticks are the most harmful ectoparasites of domestic and wild animals as well as important vectors of disease agents to humans. In order to develop an effective tick biocontrol program, we must encourage scientists and policy makers to support this long neglected field so that it will become an active branch of research. 

The two animals most implicated in the increase of tick-borne disease are the mouse and the deer. The mice followed by the chipmunk are the greatest reservoirs for Lyme disease and perhaps other tick-borne disorders. Therefore, the mouse is the animal most responsible for transmitting disease. The deer is not responsible for that since it is not a good reservoir.  Larval and nymphal stages of the tick feed primarilary on small rodents. It is not uncommon for a mouse to carry over 100 larval ticks, and transmit disease to them.

The favored host of the adult female tick is the deer. After becoming engorged with blood at this last meal on the host animal. It then drops to the ground where it lays approximately 3,000 eggs. Therefore, the deer is the animal most responsible for the increasing numbers of ticks.
 

Intervention Strategies to Control Tick Populations

There are numerous strategies to controlling tick populations. These strategies are grouped into three general catagories:

  • Reducing tick immigration

  • Increasing tick mortality

  • Reducing tick reproduction 

4 POSTER

A topical treatment device to control adult ticks on deer. The deer come to the device to feed from a bin that contains corn. In order to feed they must roll their head against a vertical roller, laced with a "tickacide."  Since most ticks congregate on the ears, head and neck area of the deer, this drastically cuts down on the next generation of ticks that would have hatched. This is a carefully controlled and targeted use of a "tickacide" (selection is one that is not dangerous to or absorbed systemically by the deer).

BAIT-BOX

A bait box is a topical treatment device to control ticks on small rodents. The mouse or other small rodent is attracted into the device to feed and is brushed with a small dose of Fipronil. Fipronil provides 42 days of control on rodents. CDC trials have shown amazing success in reducing the tick infestation rate on mice. This can not only break the cycle of disease, but also the risk of exposure for the property owner where the devices are installed. Again this is a carefully controlled and targeted use of an acaricide. 

NEMATODES

Nematodes are microscopic roundworms. Several strains of Steinernema and strains of Heterorhabditis, are well known to science and are utilized in attacking insect pests.. They are harmless to higher vertebrates (humans and livestock, for instance). In a limited field test by Doloris Hill, Ph.D, U.S.D.A., 95 -100% of adult engorged females were killed

PHEROMONES

Chemical secreted by ticks that guide behavior such as assembly, attachment, sex and primer. Scientists are examining these in order to replicate them and use them to control tick numbers. Pheromones are species specific so they are environmentally safe. 

FUNGUS

Entomopathic fungi have been widely used for biological control of agricultural pests. Several of them cause mortality of ticks. 

PARASITOIDS

Tiny sting-less wasps that lay eggs in the body of ticks. When the bees hatch they kill the ticks. 
  

The goal is to make Dutchess County a role model for other communities to follow in drastically reducing Lyme disease and other tick-borne illnesses. This will be done with integrated research programs comprised of  multifaceted, environmentally safe tick control programs, and education of residents to alter their self protection behavior and landscape management around their homes. Consistent with these goals are the following projects.

The US Centers for Disease Control has awarded a three year $300,000 grant to reduce Lyme Disease in Dutchess County.  This is to be accomplished through education, surveys, and tick reduction intervention. Four areas that have the highest numbers of  individuals with Lyme disease are being carefully monitored to determine how much of an effect intervention with "4 - Poster" deer stations and Maxforce Tick Management System (see '4-Poster' and 'Bait-box' above) will have on the numbers of ticks and their infection rate. The Dutchess County Department of Health (DC DOH), the American Lyme Disease Foundation (ALDF), The Institute of Ecosystem Studies (IES) and a Community Advisory Board (CAB) are jointly coordinating this project. (see education below for additional information).

The Dutchess County Legislature formed a Task Force to Study Tick Control, awarded a research grant to the IES (see below), and sponsored a conference of scientists to brainstorm about tick control. The Task force posted signs warning of ticks in areas of high public visitation. Among other items being studied are deer intervention modalities,  targeted controlled spraying of recreation areas, the use of other natural predators, etc. Stop Ticks On People educational web site was an outcrop of the Task Force (www.StopTicks.org)..

The IES is the primary investigator for the CDC grant. It is also performing research on naturally occurring environmental fungus that causes mortality of ticks; with a goal to produce a commercially available product. Additionally ticks have been analyzed by the Institute to determine the infection rates of numerous tick-borne organisms.
 

There is much promising research in the field of tick control by federal agencies (CDC, USDA, NIH, the Armed Services), state agencies (CT, TX, CA, etc.),  university centers and private institutions.  In spite of  this we do not already have solutions that have reduced human and animal exposure to ticks due to lack of public awareness, funding, and priorities. 

A prime example of neglect of appropriate funding is the situation in NYS which has the highest number of people infected with Lyme disease. The NYS DOH Tick Borne Disease Institute (TBDI) responsible for this kind of research is funded with only $150,000, while two years in a row $31 million was budgeted for West Nile Virus. In fact, researchers in New York and elsewhere were reassigned from the more prevalent debilitating tick-borne diseases to work on West Nile Virus.

We are now 25 years into Lyme disease and we have not progressed very far although millions have been spent in research for testing and cures.  In these twenty five years tick numbers have grown like wildfire and the number of diseases identified to be caused by them have been increasing as well. Thus, many more people are coming into contact with ticks, and are being infected with more than one disease which only complicates the already difficult problems of  diagnosis, treatment and cure. One would have to wonder if a fraction of this money had been spent on tick reduction if  there would even be a tick-borne disease problem today?

The 1999 Annual Review of Entomology, "Pathogens and Predators of Ticks and Their Potential in Biological Controls," says it best: "We must encourage scientists and policy makers to turn this long neglected, important field into an active branch of research..." This is necessary to develop an effective tick biocontrol program.

When a three year old child has 23 ticks removed during her bath after a visit to a rural park in Dutchess County, you know it's time to do something. Additionally, the myth that people do not die from Lyme disease needs to be dispelled, although rare, they do, from complications directly caused by Lyme, and from other tick-borne diseases which can be fatal.

What is needed is public action. You and others are needed to start demanding your local,  state, and federal representatives to redirect future funding priorities where it can have the most dramatic effect, tick control, to reduce human and animal exposure to these blood sucking disease ridden parasites!

Check the following web sites to find your representatives:

Federal:

United States Senate
House of Representatives

NY State:

New York State Senate
New York State Assembly

UPDATE ON RESEARCH INITIATIVES

 

Stephen Wikel, Ph.D.

 

Anti-tick Vaccine Research

 

            Significant progress is being made in characterizing host responses to tick infestation and tick countermeasures to those responses. The spectrum of tick modulation of host immune defenses is extensive and increasingly important links being made between those events and tick transmission of infectious agents. A recent example is the finding that Ixodes scapularis, a vector of Lyme disease, babesiosis and granulocytic anaplasmosis, and Dermacentor andersoni, a vector of Rocky Mountain spotted fever, both down regulate adhesion molecules that are essential for cells of the immune response to leave the circulation, cross endothelial cells of blood vessels and enter tissues. These changes in adhesion molecule expression differ for each tick species and they correlate with changes that would impair the ability of the host to mount an effective immune response to both tick and infectious agents transmitted by those species.

            Extensive analyses are being conducted of gene and protein expression in tick salivary glands. Rapid progress is being made in linking genes and their products to specific functions, such as inducing or modulating host defenses. A few comments can be made about emerging findings. During the course of feeding by Ixodes scapularis the protein composition of the saliva changes with new proteins being expressed at different times and with other proteins no longer expressed. The magnitude of those changes appears to be much greater than previously recognized. In addition, ticks appear to generate slightly different copies of molecules that are essential for successful blood feeding. Those molecules appear to be highly conserved at their active sites, but the remainder of the molecule can be structurally very different. This �variant redundancy� is likely a away to avoid host immune responses that could target key molecules for tick survival.

            A recent study correlated human skin reactivity to repeated tick bites with heightened resistance to infection with Borrelia burgdorferi. Studies are underway to identify the spectrum of human immune responses to tick bite and their possible correlation with resistance to tick transmitted infections. Due to research on genes and proteins expressed by tick salivary glands, and the forthcoming data from the Ixodes scapularis genome project, the molecules responsible for those responses will ultimately be identified.

            The overarching goal of all this research is to identify molecules that can be incorporated into vaccines that block transmission of tick-borne infectious agents.

 

 

Ixodes scapularis Genome Project

 

            The Ixodes scapularis genome is the first tick genome to be sequenced and information obtained will provide an unprecedented resource for the study of tick biology and tick-host-pathogen interactions. The Microbial Sequencing Centers (http://www.niaid.nih.gov/dmid/genomes/mscs/) of the National Institute of Allergy and Infectious Diseases, National Institutes of Health were established with a significant commitment to sequencing the genomes of microorganisms considered to be possible bioterrorism threats, emerging and re-emerging infectious diseases, and arthropod vectors of human disease. The Ixodes scapularis genome project is a collaborative effort of an international community of tick researchers, the National Institutes of Health and the Microbial Sequencing Centers. The project co-directors are Dr. Catherine Hill, Department of Entomology, Purdue University, West Lafayette, IN 47907 and Dr. Stephen Wikel, Center for Microbial Pathogenesis, School of Medicine, University of Connecticut Health Center, Farmington, CT 06030.

            The project is underway and the white paper describing the genome project can be viewed in its entirety at http://www.entm.purdue.edu/ig/overview.html. The first phase of the project involves (1) massive sequence analysis of cDNA libraries, 100,000 clones, composed of all tissues from all developmental stages; and, (2) complete end to end sequencing of approximately 40 randomly chosen large-insert bacterial artificial chromosome, BAC, clones containing I. scapularis genomic DNA. This phase provides information about the genes, their density, repetitive elements and the degree of polymorphism in the sequenced tick tissues. The second phase is whole-genome random shotgun sequencing to provide sufficient information for assembly and annotation of large sections of the genome. The size of the Ixodes scapularis genome is approximately two-thirds the size of the human genome. The Ixodes scapularis genome is approximately seven times larger than that of the malaria vector mosquito, Anopheles gambiae. A small tick has a very large genome and abundant information to reveal.

            All sequence data generated will be provided rapidly and in an unrestricted manner through public databases. The information obtained will be an unparalleled resource for the tick research community and will provide the basis for rapid advances, particularly in those areas that have been previously difficult to study.

 

For more information, please refer to our calendar of events.
 

 

 


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