Are Abundances of Diseases in Local Deer Ticks Changing?
Introduction
The Main purpose of this ongoing study is to monitor the prevalence and spread of three
tick-borne pathogens in the blacklegged (deer) tick population from Schmeeckle
Discussion
Author: Nathan D. Nelson (Biochemistry)
Mentor: Dr. Diane A. Caporale
Department of Biology
This study shows that, within the last 15 years, the
prevalence of Borrelia burgdorferi, Anaplasma
Reserve. Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne
phagocytophilum, and Babesia microti have oscillated from
illness, where symptoms start flu-like and can develop into joint pain and brain swelling.
year to year, with an overall increase. Abiotic factors, such
Anaplasmosis is a disease developed from an intracellular infection of Anaplasma
phagocytophilum, which also causes flu-like symptoms. Babesiosis is a disease caused
by Babesia microti which is a protozoan parasite that infects red blood cells, causing malarialike symptoms and anemia. Deer ticks first pick up these pathogens from rodents and, after
Result
s
as weather conditions, may play a role in this increase. For
example, researchers have found a direct correlation
between adult tick abundance and June rainfall levels two
years prior to their collection (that is, when they hatch from
molting, can then transmit them to people. Since year 2000, ticks near the trail around Lake
eggs). In addition, researchers have found a direct
Jonas have been monitored every fall by Biology 319 students for Borrelia infection, and
correlation between tick abundance and Borrelia infection
student researchers have been identifying ticks carrying Anaplasma, Babesia, or any
rates in ticks. We found that Borrelia levels increased two
combination of the three pathogens. Previous results have shown new emergences
years after higher precipitation in June and decreased two
of Anaplasma and Babesia, and increases in prevalence of all three. Here I report the current
years later with lower June precipitation. However, a lag of
infection rates and co-infection rates of these pathogens in deer ticks collected fall 2014 and
about year was observed for Anaplasma. Babesia seems to
provide ecological explanations for the changes in infection rates from year to year.
be unaffected by the amount of precipitation in June.
Predictions of future changes in abundance of these disease-causing agents are provided.
Some researchers have found that winter weather can
also dictate the prevalence of tick borne pathogens two years
Methods
after it occurs. By this logic, a winter with very cold
temperature and low precipitation would have low tick
abundance two years later and, therefore, have low pathogen
levels as well. This was observed in years 2002, 2005, 2007
and 2010, where pathogen levels decreased from the
previous year. In addition, the most optimal condition for tick
abundance and pathogen prevalence would be when June
rainfall is high and winter temperatures are mild with snow
cover. This was observed in 2003, 2006 and 2011, where
pathogen levels increased. Our data confirmed these
Prevalence of Tick Borne Pathogens
Actual
Year
2013
(Predicted)
2014
(2015)
observations for Borrelia but did not for the other two
(2016)
pathogens. This could be due Anaplasma and Babesia
Borrelia
burgdorferia
35.4%
36.0%
(36%)
(37%)
Anaplasma
phagocytophilum
16.5%
10.3%
(11%)
(10%)
populations are not completely established yet.
Using abiotic factors from 2013 and 2014, along with
Babesia
microti
Co-infected with
any two pathogens
5.2%
8.4%
7.8%
7.1%
(9%)
(5%)
(10%)
(10%)
trends that have been noticed in previous years, we predict
the prevalence of tick borne pathogens in 2015 and 2016.
Literature Cited
Acknowledgments
Centers for Disease Control and Prevention. Anaplasmosis. 8 July 2013.
http://www.cdc.gov/anaplasmosis/index.html
Centers for Disease Control and Prevention. Lyme disease. 6 December 2013.
http://www.cdc.gov/lyme/stats/
Centers for Disease Control and Prevention. Parasites-Babesiosis. 4 February 2014.
http://www.cdc.gov/parasites/babesiosis/
Exper. Appl. Acar (2002) 28: 249-256
College of Letters and Science
Matthew Swiatnicki
Benjamin Pietsch
Biology 319 Students
URSCA Fund