UMaine Tick Surveillance Program Annual Report - 2019 INTRODUCTION The University of Maine Cooperative Extension Tick Lab conducts surveillance of ticks and tick-borne pathogens to track their distribution, detect trends or changes in tick activity, and to identify areas of risk for tick-borne disease in Maine. In 2019, the UMaine Extension Tick Lab began accepting tick samples from the public for tick-borne pathogen testing. For $15, Maine residents can have ticks tested for the causative agents of Lyme disease, anaplasmosis, and babesiosis; the three most common tick-borne diseases. A free tick identification program also continues to be offered. This report summarizes the information gathered through the passive surveillance associated with the UMaine Extension Tick Surveillance Program. Passive surveillance refers to tick specimens found and submitted by members of the public and can potentially result in a bias toward certain geographic locations or uncertainty about where a specific sample was collected. All samples were submitted to the Tick Lab within the UMaine Cooperative Extension Diagnostic & Research Laboratory. For more information on ticks in Maine or on submitting a tick to the Tick Lab, please visit us online at: ticks.umaine.edu 2019 Annual Report BACKGROUND Ticks and tick-borne diseases have become a significant public health issue in Maine and throughout the eastern United States. Lyme disease is the most commonly reported vector-borne disease in the US, and reported cases have been steadily increasing throughout much of the state. In addition to Lyme disease, cases of anaplasmosis and babesiosis are also on the rise. Other tick-borne diseases known to occur in Maine include Borrelia miyamotoi disease and the serious but relatively rare Powassan virus. The primary vector of these diseases, the deer tick or black-legged tick, has greatly increased in both population size and geographic range within the state. Furthermore, Maine faces significant threats related to invasive tick species including the lone star tick and Asian long-horned tick, both of which can have serious impacts on the health of humans, wildlife, and domestic animals. There are fifteen different tick species that have been found in Maine, though not all are permanent residents. Some may arrive in the state on wildlife hosts and do not establish viable populations. Other species have thrived in Maine and are now widespread throughout much of the state. The most commonly encountered tick species in Maine are the deer tick (Ixodes scapularis), the American dog tick (Dermacentor variabilis), and, to a lesser extent, the woodchuck tick (Ixodes cookei). PURPOSE Combatting the threats associated with ticks is an immense challenge that relies heavily on an integrated approach that includes monitoring tick populations, reducing tick and host habitat, managing ticks and their wildlife hosts, and widespread educational outreach on personal protection. The tick surveillance associated with the UMaine Extension Tick Lab is an attempt to gain information on the geographic spread of ticks and tick-borne disease in Maine and to provide information on the risk of encountering ticks. The Tick Lab is not a medical lab and does not provide medical information. The testing of tick samples is intended to provide information on ticks and their associated pathogens in Maine and is not intended to be used in human health assessment or to be interpreted as a medical diagnosis. If you have been bitten by a tick, do not wait until tick testing results are available to consult with your doctor. This report was prepared by Griffin Dill and Tom Rounsville, University of Maine Cooperative Extension. Questions regarding the report can be directed to tickID@maine.edu. 2 2019 Annual Report TICK SPECIES IDENTIFICATION A total of 2,697 ticks were submitted to the UMaine Extension Tick Surveillance Program in 2019, with samples submitted from each of the state’s 16 counties and from 358 towns. The first sample arrived to the lab for testing on April 1st and the final sample of 2019 arrived on December 30th. The majority of the ticks submitted were identified as deer ticks (Ixodes scapularis), while American dog ticks (Dermacentor variabilis) also made up a significant portion of the submissions. Lone star ticks (Amblyomma americanum), a species of significant medical importance, were also submitted. Lone star ticks are not known to have established permanent populations in Maine, but are established in other New England states. They are sporadically found in Maine, most likely the result of being transported on migratory wildlife. Of the 10 lone star ticks that were submitted to the program, five were related to Maine residents travelling to other states, while the other five samples were acquired in Maine, originating from Cumberland, Knox, Kennebec, and Penobscot Counties. Tick Species Submitted to the UMaine Extension Tick Lab in 2019 (Table 1) Tick Species Common Name Total Ixodes scapularis Deer tick or blacklegged tick 2056 Dermacentor variabilis American dog tick 585 Ixodes cookei Woodchuck tick 37 Amblyomma americanum Lone star tick 10 Ixodes marxi Squirrel tick 1 Ixodes muris Mouse tick 1 Unknown Specimens damaged during removal/delivery 7 Deer Tick (Ixodes scapularis) Submissions by Life Stage and Feeding Status (Table 2) Life Stage Adult Females Adult Males Nymphs Larvae Unfed Partially Engorged Fully Engorged Engorgement Unknown* Total 624 760 25 32 1441 - - - - 30 118 427 15 5 565 7 13 0 0 20 * Some specimens arrived to the lab too damaged to determine feeding status. Though male ticks may feed for brief periods, they do not become engorged. 3 2019 Annual Report SEASONALITY OF TICK SUBMISSIONS The risks associated with ticks and tick-borne disease varies by season, based upon multiple factors including the tick’s life cycle, weather conditions, and host availability. Adult deer ticks are generally most active from early spring to late fall with two peaks, one in April or May and another in late October or early November. Nymph numbers usually peak in June and early July. Deer ticks can remain active as long as the temperature is above freezing, thus it is also possible to encounter them during the winter months. American dog tick activity tends to peak in early summer with populations becoming inactive by early fall. Deer Ticks (Ixodes scapularis) Collected by Week (Fig. 1) 180 160 Number of Ticks 140 120 100 80 60 40 20 3/26/2019 4/2/2019 4/9/2019 4/16/2019 4/23/2019 4/30/2019 5/7/2019 5/14/2019 5/21/2019 5/28/2019 6/4/2019 6/11/2019 6/18/2019 6/25/2019 7/2/2019 7/9/2019 7/16/2019 7/23/2019 7/30/2019 8/6/2019 8/13/2019 8/20/2019 8/27/2019 9/3/2019 9/10/2019 9/17/2019 9/24/2019 10/1/2019 10/8/2019 10/15/2019 10/22/2019 10/29/2019 11/5/2019 11/12/2019 11/19/2019 11/26/2019 12/3/2019 12/10/2019 12/17/2019 12/24/2019 0 adults nymphs American Dog Ticks (Dermacentor variabilis) Collected by Week (Fig. 2) 180 140 120 100 80 60 40 20 0 3/26/2019 4/2/2019 4/9/2019 4/16/2019 4/23/2019 4/30/2019 5/7/2019 5/14/2019 5/21/2019 5/28/2019 6/4/2019 6/11/2019 6/18/2019 6/25/2019 7/2/2019 7/9/2019 7/16/2019 7/23/2019 7/30/2019 8/6/2019 8/13/2019 8/20/2019 8/27/2019 9/3/2019 9/10/2019 9/17/2019 9/24/2019 10/1/2019 10/8/2019 10/15/2019 10/22/2019 10/29/2019 11/5/2019 11/12/2019 11/19/2019 11/26/2019 12/3/2019 12/10/2019 12/17/2019 12/24/2019 Number of Ticks 160 4 2019 Annual Report All Ticks Received For Identification And/Or Testing 12.5 25 50 Miles I I All Ticks Received - 2019 1 Dot 1 Tick Received Each dot randomly placed inside town boundary of location where tick was collected THE UNIVERSITY OF 373., For More Information Contact: A I Cooperative Extension 2019 Annual Report lxodes scapularis (Deer Ticks) Received for Identification And/Or Testing 12.5 25 50 Miles I I I lxodes scapularis Received - 2019 1 Dot 1 Tick Received Each dot randomly placed inside town boundary of location where tick was collected THE UNIVERSITY OF ?3:5 For More Information Contact: A I Cooperative Extension 2019 Annual Report Dermacentor variabilis (Dog Ticks) Received for Identification A 0 12.5 25 50 Miles Dermacentor variabilis Received - 2019 1 Dot 1 Tick Received Each dot randomly placed inside town boundary of location where . >36 tick was collected THE UNIVERSITY OF 5' For More Information Contact: MA I TICle@malne.edu Cooperative Extension 2019 Annual Report TICK PATHOGEN TESTING Pathogen testing was conducted for the causative agents of Lyme disease (Borrelia burgdorferi), anaplasmosis (Anaplasma phagocytophilum), and babesiosis (Babesia microti), using a multiplex real-time polymerase chain reaction (PCR) assay. As the deer tick (Ixodes scapularis) is the known vector of these pathogens, testing was conducted primarily on this species. The figures below display the percentage of deer ticks infected with each pathogen and ticks co-infected with multiple pathogens, as well as a weekly record of infected tick submissions. Infection Prevalence in Submitted Deer Ticks - 2019 (Table 3) Pathogen % of infected nymphs % of infected adults % of infected ticks Positive for at least 1 pathogen 33.9% 49.8% 44.9% Borrelia burgdorferi 29.3% 43.0% 38.8% Anaplasma phagocytophilum 6.7% 8.7% 8.1% Babesia microti 5.3% 6.5% 6.1% Borrelia + Anaplasma 3.1% 3.5% 3.3% Borrelia + Babesia 2.7% 3.2% 3.0% Anaplasma + Babesia 0.2% 0.4% 0.3% Borrelia + Anaplasma + Babesia 0.7% 0.7% 0.7% Infection Prevalence in Submitted Deer Ticks by Week - 2019 (Fig. 3) 80 60 50 40 30 20 10 0 3/26/2019 4/2/2019 4/9/2019 4/16/2019 4/23/2019 4/30/2019 5/7/2019 5/14/2019 5/21/2019 5/28/2019 6/4/2019 6/11/2019 6/18/2019 6/25/2019 7/2/2019 7/9/2019 7/16/2019 7/23/2019 7/30/2019 8/6/2019 8/13/2019 8/20/2019 8/27/2019 9/3/2019 9/10/2019 9/17/2019 9/24/2019 10/1/2019 10/8/2019 10/15/2019 10/22/2019 10/29/2019 11/5/2019 11/12/2019 11/19/2019 11/26/2019 12/3/2019 12/10/2019 12/17/2019 12/24/2019 Number of Positives 70 Borrelia (Lyme) Anaplasma Babesia 8 2019 Annual Report TICK PATHOGEN TESTING Tick populations and infection rates can vary greatly over both large and small geographic distances. The numbers in the following table represent the amount of deer ticks that tested positive from each county. The percentage indicates the number of ticks that tested positive divided by the total number of deer ticks that were tested from that county. Submissions testing positive for each pathogen are mapped on the following three pages. Infection Prevalence in Submitted Deer Ticks - 2019 (Table 4) Deer Ticks Submitted Deer Ticks Tested Borrelia (Lyme) Anaplasma 70 66 26 (39.4%) 5 (7.6%) 7 (10.6%) 5 5 0 (0.0%) 0 (0.0%) 0 (0.0%) 347 328 116 (35.4%) 36 (11.0%) 26 (7.9%) Franklin 33 30 15 (50.0%) 1 (3.3%) 0 (0.0%) Hancock 332 325 121 (37.2%) 23 (7.1%) 11 (3.4%) Kennebec 136 128 43 (33.6%) 13 (10.2%) 5 (3.9%) Knox 140 135 62 (45.9%) 11 (8.1%) 15 (11.1%) Lincoln 218 206 91 (44.2%) 10 (4.9%) 13 (6.3%) Oxford 52 49 18 (36.7%) 8 (16.3%) 3 (6.1%) Penobscot 251 229 90 (39.3%) 11 (4.8%) 4 (1.7%) Piscataquis 25 24 6 (25.0%) 0 (0.0%) 0 (0.0%) Sagadahoc 49 48 19 (39.6%) 4 (8.3%) 4 (8.3%) Somerset 39 36 14 (38.9%) 2 (5.6%) 0 (0.0%) 145 141 59 (41.8%) 10 (7.1%) 10 (7.1%) 45 43 16 (37.2%) 5 (11.6%) 2 (4.7%) 128 125 42 (33.6%) 14 (11.2%) 16 (12.8%) 41 39 21 (53.8%) 6 (15.4%) 4 (10.3%) 2056 1957 759 (38.8%) 159 (8.1%) 120 (6.1%) County Androscoggin Aroostook Cumberland Waldo Washington York Outside of Maine TOTAL Babesia 9 2019 Annual Report lxodes scapular/s (Deer Ticks) Positive for Borrelia burgdon?eri sensu lato (Causitive Ag sease) 0 12.5 25 50 Miles I ?Ticks Positive for Borrelia burgdorferi sensu Iato DNA - 2019 1 Dot 1 Positive Test Each dot randomly placed inside town boundary of location where tick was collected THE UNIVERSITY OF For More Information Contact: A I Ticle@maine.edu Cooperative Extension 2019 Annual Report Ixodes scapularis (Deer Ticks) Positive for Anaplasma phagocytophilum (Causitive Ag mosis) 0 12.5 25 50 Miles icks Positive for Anaplasma phagocytophilum DNA- 2019 1 Dot- - 1 Positive Test Each dot randomly placed inside town boundary of location where tick was collected THE UNIVERSITY OF For More Information Contact: A IN Ticle@maIne.edu Cooperative Extension 2019 Annual Report Ixodes scapularis (Deer Ticks) Positive for Babesia microti (CausitiveA of Bab 0 12.5 25 50 Miles icks Positive for Babesia microti DNA - 2019 1 Dot 1 Positive Test Each dot randomly placed inside town boundary of location where tick was collected THE UNIVERSITY OF For More Information Contact: A IN TICle@maine.edu Cooperative Extension 2019 Annual Report HOST ASSOCIATIONS Many of the tick species in Maine are host specific, in that they feed on a limited range of wildlife species and are not commonly found on humans. The tick species most commonly encountered by humans, the deer tick and American dog tick, are generalist feeders that will attach and feed upon humans as well as a wide variety of different animal species. The ticks submitted to the UMaine Tick Lab were overwhelmingly found on human hosts (93%), with pets and other hosts making up the remaining small percentage of submissions. Tick Submissions by Host - 2019 (Fig. 4) The risk of encountering ticks can vary depending upon age, with the young and very old often considered to be most at risk. During 2019, deer tick nymphs were commonly submitted from children under the age of 15, while adult deer ticks were most commonly submitted by those over the age of 45. Deer Tick (Ixodes scapularis) Submissions by Age Group - 2019 (Fig. 5) 450 400 350 300 250 200 150 100 50 0 0-4 5-14 15-24 Adults 25-44 45-64 65+ Nymphs 13 2019 Annual Report TICK FEEDING SITES Once the tick is on a host it may immediately attach and start feeding or it may wander around before settling on a spot. Feeding may last several days or more than a week depending on the species and life stage. Females utilize these extended feedings, while Deer Tick Attachment Sites – All Ages (Fig. 6) adult males only take small occasional blood meals, if they feed at all. The vast majority of ticks submitted from human hosts (95%) were discovered while attached and feeding, while the remaining 5% were found crawling on the body. Feeding sites were fairly evenly distributed across the body on average (Fig. 6), however, there were some differences based upon age (Fig. 7). Deer ticks were most commonly found on the head of children under the age of 15, however, they were more often attached to the legs of adults. The tick’s life stage also made a difference, with deer tick nymphs more often attached to the legs than other parts of the body. Deer Tick Attachment Sites by Age – 2019 (Fig. 7) 350 Number of Ticks 300 250 200 150 100 50 0 Arm Armpit Groin Head Adults Leg Neck Torso (Back) Torso (Front) Children 14 2019 Annual Report HUMAN ACTIVITY One of the goals of UMaine Extension’s Tick Surveillance Program is to identify potential risk factors for contacting ticks. Certain human activities may increase this potential for contact and subsequently lead to increased risk of contracting a tick-borne illness. The following table summarizes the human activities associated with the deer ticks (Ixodes scapularis) that were submitted to the UMaine Tick Lab in 2019. The listed activities represent just some of the potential ways in which contact with ticks can be made. Human Activity at the Time of Deer Tick (Ixodes scapularis) Acquisition (Table 5) Activity ATV Riding Adults Nymphs Total 5 3 8 (0.4%) Bicycling 10 6 16 (0.8%) Camping 15 41 56 (2.9%) 5 2 7 (0.4%) Gardening/Yardwork 529 198 727 (38.2%) Hiking 129 55 184 (9.7%) Hunting / Trapping 29 1 30 (1.6%) Occupational - Agriculture 16 3 19 (1.0%) Occupational – Forestry/Logging 18 4 22 (1.2%) Occupational - Other 13 5 18 (0.9%) 178 56 234 (12.3%) Playing Outside 96 49 145 (7.6%) Playing Sports 29 20 49 (2.6%) Running 6 5 11 (0.6%) Walking 267 108 375 (19.7%) Fishing Other 15 2019 Annual Report LIMITATIONS OF THE DATA The information in this report is preliminary as of December 31, 2019. Tick samples collected in 2019 that are submitted after this date will be added to the data set and included in future reports. As this is the first annual report, it represents only a snapshot in time and cannot be used to examine long-term trends. This report provides a general summary of the data collected and does not attempt to draw specific conclusions. Each tick is counted individually, but multiple ticks may be submitted from a single host or person, which can thus impact the interpretation of geographic data. Towns without tick submissions or positive test results should not be interpreted as not having tick populations or tick-borne disease. The data in this report is generated from passive surveillance (tick specimens found and submitted by members of the public) and can potentially result in a bias toward certain geographic locations or uncertainty about where a specific sample was collected. LOOKING AHEAD The University of Maine Cooperative Extension Tick Lab plans to expand upon its Tick Surveillance Program through the addition of tests for other emerging tick-borne pathogens. Currently, the Tick Lab tests for the three most common tick-borne illnesses, Lyme disease, anaplasmosis, and babesiosis. In April of 2020, Borrelia miyamotoi will be added to the deer tick testing panel and a new testing panel will be added for non-deer tick samples. American dog ticks, lone star ticks, and other non-deer tick samples will be screened for the causative agents of Rocky Mountain spotted fever, Ehrlichiosis, and Tularemia. In addition to the enhanced passive surveillance, the Tick Lab also plans to increase field monitoring for disease-carrying ticks throughout Maine. ACKNOWLEDGEMENTS Special thanks to all those who submitted ticks to the program, the Maine state government, and the people of Maine for supporting this program. The Tick Lab is part of the Pest Management Unit within the University of Maine Cooperative Extension Diagnostic and Research Laboratory. The Diagnostic and Research Lab is coordinated by Jim Dill and combines veterinary diagnostics, pest management, and aquatic animal health research under one roof. The University of Maine is an EEO/AA employer, and does not discriminate on the grounds of race, color, religion, sex, sexual orientation, transgender status, gender expression, national origin, citizenship status, age, disability, genetic information or veteran’s status in employment, education, and all other programs and activities. The following person has been designated to handle inquiries regarding non-discrimination policies: Director of Equal Opportunity, 101 North Stevens Hall, University of Maine, Orono, ME 04469-5754, 207.581.1226, TTY 711 (Maine Relay System). 16