Vital Signs: Trends in Reported Vectorborne Disease Cases — United States and Territories
Rosenberg R, Lindsey NP, Fischer M, et al. 2004–2016.
Centers for Disease Control, MMWR Morb Mortal Wkly Rep 2018;67:496–501.
Vectorborne diseases are major causes of death and illness worldwide. In the United States, the most common vectorborne pathogens are transmitted by ticks or mosquitoes, including those causing Lyme disease; Rocky Mountain spotted fever; and West Nile, dengue, and Zika virus diseases. This report examines trends in occurrence of nationally reportable vectorborne diseases during 2004–2016. A total 642,602 cases were reported. The number of annual reports of tickborne bacterial and protozoan diseases more than doubled during this period, from >22,000 in 2004 to >48,000 in 2016. Lyme disease accounted for 82% of all tickborne disease reports during 2004–2016. The occurrence of mosquitoborne diseases was marked by virus epidemics. Transmission in Puerto Rico, the U.S. Virgin Islands, and American Samoa accounted for most reports of dengue, chikungunya, and Zika virus diseases; West Nile virus was endemic, and periodically epidemic, in the continental United States.
Surveillance for Lyme Disease – United States, 2008-2015
Schwartz AM, Hinckley AF, Mead PS, Hook SA, Kugeler KJ.
Morbidity and Mortality Weekly Report 2017;66(No. SS-22):1–12.
Results: During 2008–2015, a total of 275,589 cases of Lyme disease were reported to CDC (208,834 confirmed and 66,755 probable). Although most cases continue to be reported from states with high incidence in the Northeast, mid-Atlantic, and upper Midwest regions, case counts in most of these states have remained stable or decreased during the reporting period. In contrast, case counts have increased in states that neighbor those with high incidence. Overall, demographic characteristics associated with confirmed cases were similar to those described previously, with a slight predominance among males and a bimodal age distribution with peaks among young children and older adults. Yet, among the subset of cases reported from states with low incidence, infection occurred more commonly among females and older adults. In addition, probable cases occurred more commonly among females and with a higher modal age than confirmed cases.
Incidence of clinician-diagnosed Lyme disease, United States, 2005–2010
Nelson CA, Saha S, Kugeler KJ, Delorey MJ, Shankar MB, Hinckley AP, et al.
Emerging Infectious Diseases, Vol 12, No 9, September 2015. (Cited August 12, 2015.)
Of 103,647,966 person-years, 985 inpatient admissions and 44,445 outpatient LD diagnoses were identified. Epidemiologic patterns were similar to US surveillance data overall. Outpatient incidence was highest among boys 5–9 years of age and persons of both sexes 60–64 years of age. On the basis of extrapolation to the US population and application of correction factors for coding, we estimate that annual incidence is 106.6 cases/100,000 persons and that ˜329,000 (95% credible interval 296,000–376,000) LD cases occur annually. LD is a major US public health problem that causes substantial use of health care resources.
Comparison of Lyme Disease Prevalence and Disease Reporting in an Endemic Area
Journal of Microbiology Research, Vol. 3 No. 6, 2013, pp. 261-265.
Thus, in a region endemic for Lyme disease, cases are diagnosed by physicians more frequently than cases are reported. Additionally, a significant proportion of the study population reported signs and symptoms consistent with late-stage Lyme disease. Together, these results indicate underestimation of Lyme disease risk and an increase in public health burden for people living in endemic areas.
Lyme Disease Testing by Large Commercial Laboratories in the United States
Alison F. Hinckley, Neeta P. Connally, James I. Meek, Barbara J. Johnson, Melissa M. Kemperman, Katherine A. Feldman, Jennifer L. White, and Paul S. Mead
Clinical Infectious Diseases. published 6 July 2014.
Seven participating laboratories performed approximately 3.4 million LD tests on approximately 2.4 million specimens nationwide at an estimated cost of $492 million. Two-tiered testing accounted for at least 62% of assays performed; alternative testing accounted for <3% of assays. The estimated frequency of infection among patients from whom specimens were submitted ranged from 10% to 18.5%. Applied to the total numbers of specimens, this yielded an estimated 240 000 to 444 000 infected source patients in 2008.
‘Lyme Disease’: ancient engine of an unrecognized boreliosis pandemic?
W. T. Harvey, P. Salvato
Summary Unexpectedly we have found large numbers of chronically ill Borrelia burgdorferi PCR- and seropositive patients in Houston, Texas, a zoonotically ‘non-endemic’ area. In order to understand this finding prior to sufficient data availability, we chose to examine critically currently accepted but troublesome ‘Lyme disease’ concepts. Our method was to analyze each foundation ‘Lyme disease’ premise within the context of available medical and veterinary literature, then to reconstruct the disease model consistent with the preponderance of that data. We find the present conceptualization of the illness seriously truncated, with a high likelihood of two distinct but connected forms of human B. burgdorferi infection. The yet-unrecognized form appears to have a broader clinical presentation, wider geographic distribution, and vastly greater prevalence. We conclude that ‘Lyme disease’ currently acknowledges only its zoonosis arm and is a limited conceptualization of a far more pervasive and unrecognized infection state that must be considered a global epidemic.
Blacklegged Ticks Found in Half of U.S. Counties
Entomological Society of America, Annapolis, Maryland
January 19, 2016
Lyme disease is transmitted by the blacklegged tick (Ixodes scapularis) and the western blacklegged tick (Ixodes pacificus), and the range of these ticks is spreading, according to research published in the Journal of Medical Entomology.
They found that the blacklegged tick has been reported in more than 45% of U.S. counties, compared to 30% of counties in 1998. Even more alarming, the blacklegged tick is now considered established in twice the number of counties as in 1998.
Evolution of Northeastern and Midwestern Borrelia burgdorferi, United States.
Emerging Infectious Disease, 2010 Jun;16(6):911-7.
Brisson D, Vandermause MF, Meece JK, Reed KD, Dykhuizen DE.
The per capita incidence of human Lyme disease in the northeastern United States is more than twice that in the Midwest. However, the prevalence of Borrelia burgdorferi, the bacterium that causes Lyme disease, in the tick vector is nearly identical in the 2 regions. The disparity in human Lyme disease incidence may result from a disparity in the human invasiveness of the bacteria in the Northeast and Midwest caused by fundamentally different evolutionary histories.
Recent and rapid population growth and range expansion of the Lyme disease tick vector, Ixodes scapularis, in North America
Khatchikian, C. E., Prusinski, M. A., Stone, M., Backenson, P. B., Wang, I.-N., Foley, E., Seifert, S. N., Levy, M. Z. and Brisson, D.
Evolution, online first, July 6, 2015.
Populations of blacklegged ticks have established and flourished in areas of North America previously thought to be devoid of this species.
A Bayesian spatio-temporal model for forecasting the prevalence of antibodies to Borrelia burgdorferi, causative agent of Lyme disease, in domestic dogs within the contiguous United States
Stella C. Watson, Yan Liu, Robert B. Lund, Jenna R. Gettings, Shila K. Nordone, Christopher S. McMahan, Michael J. Yabsley
PLoS ONE 12(5): e0174428.
This paper models the prevalence of antibodies to Borrelia burgdorferi in domestic dogs in the United States using climate, geographic, and societal factors. We then use this model to forecast the prevalence of antibodies to B. burgdorferi in dogs for 2016.
Human pathogens associated with the blacklegged tick Ixodes scapularis: a systematic review
Nelder MP, Russell CB, Sheehan NJ, Sander B, Moore S, Li Y, Johnson S, Patel SN, Sider D.
Parasites Vectors, online first, 2016 May 5.
The blacklegged tick Ixodes scapularis transmits Borrelia burgdorferi (sensu stricto) in eastern North America; however, the agent of Lyme disease is not the sole pathogen harbored by the blacklegged tick. Seventy-eight studies were included in the final review, 72 were from the US and eight were from Canada (two studies included blacklegged ticks from both countries). Sixty-four (82 %) studies met = 75 % of the quality assessment criteria. Blacklegged ticks harbored 91 distinct taxa, 16 of these are tick-transmitted human pathogens, including species of Anaplasma, Babesia, Bartonella, Borrelia, Ehrlichia, Rickettsia, Theileria and Flavivirus. Organism richness was highest in the Northeast (Connecticut, New York) and Upper Midwest US (Wisconsin); however, organism richness was dependent on sampling effort.
The Use of Harvested White-Tailed Deer (Odocoileus virginianus) and Geographic Information System (GIS) Methods to Characterize Distribution and Locate Spatial Clusters of Borrelia burgdorferi and Its Vector Ixodes scapularis in Indiana
Lisa M. Keefe, Manuel H. Moro, Javier Vinasco, Catherine Hill, Ching C. Wu, and Eran A. Raizman. Vector-Borne and Zoonotic Diseases. December 2009, 9(6): 671-680. doi:10.1089/vbz.2008.0162.
Published in Volume: 9 Issue 6: December 9, 2009
Multiple spatial clusters of I. scapularis-infested deer were identified in western Indiana. B. burgdorferi was isolated from tick pools in 11 counties. In addition to the I. scapularis clusters, one spatial cluster of Bb-infected ticks was identified. Our current survey results and cluster analysis indicate that the western geographic regions of Indiana should be considered by the healthcare community to be at increased risk of LD compared with the rest of Indiana.
The Relationship Between Deer Density, Tick Abundance, and Human Cases of Lyme Disease in a Residential Community
Kilpatrick, Howard J.; Labonte, Andrew M.; Stafford, Kirby C.
Journal of Medical Entomology, Volume 51, Number 4, pp. 777-784(8).
Reducing deer density to 5.1 deer per square kilometer resulted in a 76% reduction in tick abundance, 70% reduction in the entomological risk index, and 80% reduction in resident-reported cases of Lyme disease in the community from before to after a hunt was initiated.
Lyme disease cases in Indiana experience an uptick of 82 percent
By John Terhune, Journal and Courier, Lafayette, Indiana
August 29, 2011
The number of Lyme disease cases has been escalating over the years in the state and county. In Indiana, the number of Lyme disease cases has increased 82 percent, rising from 34 cases in 2005 to 62 in 2009, according to the Indiana State Department of Health.
Forest and Surface Water As Predictors of Borrelia burgdorferi and Its Vector Ixodes scapularis (Acari: Ixodidae) in Indiana
E. A. Raizman, J. D. Holland, L. M. Keefe, and M. H. Moro
© 2010 Entomological Society of America
The objective of this study was to assess whether the distribution of Borrelia burgdorferi, the causative agent of Lyme disease, and its vector tick Ixodes scapularis Say (Acari: Ixodidae) across Indiana is influenced by large-scale landscape features, specifically the proportion of forest within the surrounding landscape and the distance to water features such as lakes and major streams
White-Tailed Deer (Odocoileus virginianus) as a Potential Sentinel for Human Lyme Disease in Indiana
E. A. Raizman, J. D. Holland, J. T. Shukle
Zoonoses and Public Health, Volume 60, Issue 3, pages 227–233, May 2013.
Lyme disease incident rate varied between 0.08 cases per 10,000 habitants (Johnson county) and 5.9 cases per 10,000 habitants (Warren county).
Long-term study on ticks reveals shifting migration patterns, disease risks
Indiana University, Bloomington, Indiana
May 11, 2015
“Just in the past 10 years, we’re seeing things shift considerably,” Clay said. “You used to never see lone star ticks in Indiana; now they’re very common. In 10 years, we’re likely to see the Gulf Coast tick here, too. There are several theories for why this is happening, but the big one is climate change.”
Prevalence of Borrelia miyamotoi in Ixodes ticks in Europe and the United States.
Crowder CD, Carolan HE, Rounds MA, Honig V, Mothes B, Haag H, et al.
Emerging Infectious Diseases. 2014 Oct [Cited: September 12, 2014].
Ticks were collected from California, New York, Connecticut, Pennsylvania, and Indiana in the United States and from Germany and the Czech Republic in Europe from 2008 through 2012. We found B. miyamotoi infection in ticks in 16 of the 26 sites surveyed, with infection prevalence as high as 15.4%. These results show the widespread distribution of the pathogen, indicating an exposure risk to humans in areas where Ixodes ticks reside.
Widespread distribution of ticks and selected tick-borne pathogens in Kentucky (USA).
Lockwood BH, Stasiak I, Pfaff MA, Cleveland CA, Yabsley MJ.
Ticks and Tick-Borne Diseases. 2018 Mar;9(3):738-741.
The geographical distribution of Ixodes scapularis and Amblyomma maculatum ticks is poorly understood in Kentucky.We conducted a convenience survey of wildlife species (white-tailed deer (Odocoileus virginianus), elk (Cervus canadensis) and black bears (Ursus americanus)) for ticks from October 2015 to January 2017. We detected four tick species including Amblyomma americanum, Dermacentor albipictus, I. scapularis and A. maculatum. Although the former two tick species were previously known to be widely distributed in Kentucky, we also found that I. scapularis and A. maculatum were also widespread.Because of the limited data available for pathogens from I. scapularis and A. maculatum, we tested them for Borrelia and Rickettsia spp. by polymerase chain reaction assays. Prevalence of Borrelia burgdorferi sensu stricto and Rickettsia parkeri were 11% and 3%, respectively. These data indicate that public health measures are important to prevent tick-borne diseases in Kentucky.
Borrelia burgdorferi in small mammal reservoirs in Kentucky, a traditionally non-endemic state for Lyme disease
Buchholz MJ, Davis C, Rowland NS, Dick CW.
Parasitology Research, online first 2018 Feb 7.
Prevalence of B. burgdorferi (21.8%) in Kentucky small mammals was comparable to the lowest recorded prevalence in regions where Lyme disease is endemic. Moreover, infestation of small mammals by Ixodes scapularis, the primary vector of B. burgdorferi, was rare, while Dermacentor variabilis comprised the majority of ticks collected.
Infection Prevalences of Common Tick-borne Pathogens in Adult Lone Star Ticks (Amblyomma americanum) and American Dog Ticks (Dermacentor variabilis) in Kentucky
Authors: Charissa M. Fritzen, Junjun Huang, Kathleen Westby, James D. Freye, Brett Dunlap, Michael J. Yabsley, Mike Schardein, John R. Dunn, Timothy F. Jones, Abelardo C. Moncayo
Publisher: The American Society of Tropical Medicine and Hygiene
During 2007–2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Rickettsia spp., Borrelia spp., and Ehrlichia spp. by using polymerase chain reaction. Forty-one (14.3%) ticks (31 A. americanum and 10 D. variabilis) were polymerase chain reaction–positive for a Rickettsia spp. Fourteen (4.9%) ticks (6 A. americanum and 8 D. variabilis) were positive for E. chaffeensis, and 4 A. americanum (1.4%) were positive for E. ewingii. One (0.4%) A. americanum was positive for Borrelia lonestari.
“The Lyme Disease Spirochete, Borrelia burgdorferi, in Tick Species Collected … in the Warren and Barren Counties of South Central Kentucky”
A total of 976 ticks were collected. Three different species were obtained from raccoons; Dermacentor variabilis, Amblyomma americanum, and Ixodes sp. Dermacentor variabilis was the only tick species found on opossums. Twenty-five percent (163/642) of the tick DNA samples were positive for Borrelia burgdorferi. Prevalence of B. burgdorferi by tick species was 24.4% (141/577) in D. variabilis, 40.6% (13/32) in A. americanum, and 27.6% (8/29) in I. scapularis. In the present study, 15.7% (8/51) of the total raccoon blood samples examined by PCR were positive for B. burgdorferi, while no opossum blood samples were positive. The high prevalence of B. burgdorferi in ticks common to raccoons and opossums observed in this study, as well as in a tick species that aggressively bites humans in the southeast U. S. (A. americanum), creates concern that there are ample opportunities for people to come in contact with the infected ticks on these animals.
Rickettsia parkeri and Rickettsia montanensis, Kentucky and Tennessee, USA.
Pagac BB, Miller MK, Mazzei MC, Nielsen DH, Jiang J, Richards AL.
Emerging Infectious Disease [Internet]. 2014 Oct [Cited: September 4, 2014].
We found that 14.3% (15/105) of Amblyomma maculatum and 3.3% (10/299) of Dermacentor variabilis ticks collected at 3 high-use military training sites in west-central Kentucky and northern Tennessee, USA, were infected with Rickettsia parkeri and Rickettsia montanensis.
Temporal and Spatial Distribution of Tick-Borne Disease Cases among Humans and Canines in Illinois (2000-2009).
Herrmann JA, Dahm NM, Ruiz MO, Brown WM.
Environmental Health Insights, available online, 2014 Nov 9; 8(Suppl 2):15-27. eCollection 2014.
Four tick-borne diseases (TBDs), anaplasmosis, ehrlichiosis, Lyme disease (LD), and Rocky Mountain spotted fever (RMSF), are endemic in Illinois. The prevalence of human and canine cases of all four TBDs rose over the study period with significant differences in geographic distribution within the state.
Ixodes scapularis and Borrelia burgdorferi Among Diverse Habitats Within a Natural Area in East-Central Illinois.
Rydzewski J, Mateus-Pinilla N, Warner RE, Hamer S, Weng HY.
Vector Borne and Zoonotic Diseases, online before print, 2011 Jun 20.
The minimum Bb infection prevalence of on-host I. scapularis collected in the natural area was 14% (n=56). Unlike previous studies solely focused on forested areas and Peromyscus leucopus, our study is the first to provide evidence of I. scapularis collected from prairie habitat and other reservoir hosts, particularly M. ochrogaster.
Ixodes scapularis (Acari: Ixodidae) distribution surveys in the Chicago metropolitan region.
Rydzewski J, Mateus-Pinilla N, Warner RE, Nelson JA, Velat TC.
Journal of Medical Entomology. 2012 Jul;49(4):955-9.
This study updates the I. scapularis distribution in northeast Illinois. Our random sampling of suitable tick habitats across a large geographic area of the Chicago metropolitan area suggests a widespread human exposure to I. scapularis, and, potentially, to their associated pathogens throughout the region. These results prompt continued monitoring and investigation of the distribution, emergence, and expansion of I. scapularis populations and Borrelia burgdorferi transmission within this heavily populated region of Illinois.
Emergence of Ixodes scapularis and Borrelia burgdorferi, the Lyme disease vector and agent, in Ohio.
Wang P, Glowacki MN, Hoet AE, Needham GR, Smith KA, Gary RE, Li X.
Frontiers in Cellular Infection Microbiology, 2014 Jun 4;4:70.
Collectively, these data suggest that the enzootic life cycle of B. burgdorferi has become established in Ohio, which poses risk of Lyme disease to people and animals in the area.
Geographic Expansion of Lyme disease in Michigan, 2000-2014
Paul M. Lantos, Jean Tsao, Lise E. Nigrovic, Paul G. Auwaerter, Vance Fowler, Felicia Ruffin, Erik Foster, and Graham Hickling
Open Forum Infectious Diseases (2017) ofw269. Published 09 January 2017.
Most Lyme disease cases in the Midwestern United States are reported in Minnesota and Wisconsin. In recent years, however, a widening geographic extent of Lyme disease has been noted with evidence of expansion eastwards into Michigan and neighboring states with historically low incidence rates.
Prevalence of Borrelia burgdorferi in adult female ticks (Ixodes scapularis), Wisconsin 2010–2013
Lloyd W. Turtinen, Alyssa N. Kruger and Madeleine M. Hacker
Journal of Vector Ecology, Volume 40, Issue 1, pages 195-197, June 2015.
Published surveys completed overseas in various countries (Germany, Japan, China, Norway) have shown prevalence rates of Borrelia spp. infection ranging from about 30-40% in adult Ixodes spp. In Wisconsin, unpublished surveys also reveal that as many as 40-50% of Ixodes scapularis adults in some areas may be infected. In recently published studies from the eastern United States, prevalence rates of B. burgdorferi in adult I. scapularis ranged from 27% to 45.2%. In Wisconsin, the prevalence of B. burgdorferi in I. scapularis nymphs collected from managed red pine forests from 2009 to 2013 was approximately 30%.
The Emergence of Clinically Relevant Babesiosis in Southwestern Wisconsin
Kowalski TJ, Jobe DA, Dolan EC, Kessler A, Lovrich SD, Callister SM.
Wisconsin Medical Journal. 2015 Aug;114(4):152-7.
Babesiosis should be considered endemic in southwestern Wisconsin, and testing should be considered for patients with compatible clinical and laboratory features.
Babesiosis Surveillance – Wisconsin, 2001-2015
Stein E, Elbadawi LI, Kazmierczak J, Davis JP.
Morbidity and Mortality Weekly Report (MMWR). 2017 Jul 7;66(26):687-691.
Wisconsin babesiosis surveillance data for 2001–2015 were analyzed in 3-year intervals to compare demographic, epidemiologic, and laboratory features among patients with cases of reported babesiosis. To determine possible reasons for an increase in reported Babesia infection, trends in electronic laboratory reporting and diagnosis by polymerase chain reaction testing (PCR) were examined. Between the first and last 3-year analysis intervals, there was a 26-fold increase in the incidence of confirmed babesiosis, in addition to geographic expansion.
Range Expansion and Increasing Borrelia burgdorferi Infection of the Tick Ixodes scapularis (Acari: Ixodidae) in Iowa, 1990-2013.
Oliver JD, Bennett SW, Beati L, Bartholomay LC.
Journal of Medical Entomology. 2017 Nov 7;54(6):1727-1734.
In 2013, 23.5% of nymphal and adult I. scapularis were infected with B. burgdorferi, the highest proportion of any year. Active surveillance was performed at selected sites from 2007–2009. Ixodes scapularis nymphs collected at these sites were tested for the presence of B. burgdorferi, Anaplasma phagocytophilum, and spotted fever group Rickettsia spp. (likely representing Rickettsia buchneri).Nymphs tested were 17.3% positive for B. burgdorferi, 28.9% for A. phagocytophilum, and 67.3% for Rickettsia spp. The results of these surveillance programs indicate an increasing risk of disease transmission by I. scapularis in Iowa.
Increased diversity of zoonotic pathogens and Borrelia burgdorferi strains in established versus incipient Ixodes scapularis populations across the Midwestern United States.
Hamer SA, Hickling GJ, Walker ED, Tsao JI.
Infection, Genetics and Evolution, pii: S1567-1348(14)00206-8.
Online before print 2014 Jun 17.
Analysis of 1565 adult I. scapularis ticks from 13 sites across five Midwestern states revealed that tick infection prevalence with multiple microbial agents (Borrelia burgdorferi, Borrelia miyamotoi, Babesia odocoilei, Babesia microti, and Anaplasma phagocytophilum), coinfections, and molecular genetic diversity of B. burgdorferi all were positively correlated with the duration of establishment of tick populations, and therefore generally support the center of origin – pathogen diversity hypothesis. The observed differences across the gradient of establishment, however, were not strong and were nuanced by the high frequency of coinfections in tick populations at both established and recently-invaded tick populations.
Confirmation of Borrelia burgdorferi sensu stricto and Anaplasma phagocytophilum in Ixodes scapularis, Southwestern Virginia.
Herrin BH, Zajac AM, Little SE.
Vector-Borne and Zoonotic Diseases. 2014 Nov;14(11):821-823.
These data document the presence of I. scapularis and the agent of Lyme disease in a newly established area of the Appalachian region, providing further evidence of range expansion of both the tick and public and veterinary health risk it creates.
Detection of Borrelia burgdorferi and Anaplasma phagocytophilum in the black-legged tick, Ixodes scapularis, within southwestern Pennsylvania
Scott M. Brown, Preston M. Lehman, Ryan A. Kern and Jill D. Henning
Journal of Vector Ecology, Volume 40, Issue 1, pages 180-183, June 2015.
Of the ticks collected from Pennsylvania, B. burgdorferi (causative agent of Lyme disease) was present in 114/325 (35%) and Anaplasma phagocytophilum (causative agent of Human Granulocytic Anaplasmosis) was present in 48/325 (15%) as determined by PCR analysis.
Dramatic Rise in Lyme Disease Cases in Alabama Prompts State Health Officer to Deliver Warning to Medical Professionals in 7 Alabama Counties Endemic for the Disease
October 8, 2015
The Alabama Lyme Disease Association reports that, due to a Dramatic Rise in Lyme disease cases in Alabama, State Health Officer Don Williamson recently sent a letter to Medical Professionals in Seven Alabama Counties Endemic for the disease to be aware of the symptoms and to remain vigilant
Prevalence Rates of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae), Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae), and Babesia microti (Piroplasmida: Babesiidae) in Host-Seeking Ixodes scapularis (Acari: Ixodidae) from Pennsylvania.
Hutchinson ML, Strohecker MD, Simmons TW, Kyle AD, Helwig MW.
Journal of Medical Entomology. 2015 Jul;52(4):693-8.
Infection rates were highest for B. burgdorferi (47.4%), followed by Ba. microti (3.5%) and A. phagocytophilum (3.3%). Coinfections included B. burgdorferi + Ba. microti (2.0%), B. burgdorferi + A. phagocytophilum (1.5%) and one tick positive for A. phagocytophilum + Ba. microti.
Molecular identification of Ehrlichia species and host bloodmeal source in Amblyomma americanum L. from two locations in Tennessee, United States
Jessica R. Harmon, M. Cathy Scott, Ellen M. Baker, Carl J. Jones, Graham J. Hickling
Ticks and Tick-borne Diseases, online before print, February 11, 2015.
The 9.3% prevalence of Ehrlichia spp. in ticks from the retirement community was similar to that detected at the state park site (5.5%), suggesting that the 4-Poster treatment had not been sufficient to reduce Ehrlichia spp. cycling in the tick population.
Prevalence of Rickettsiales in ticks removed from the skin of outdoor workers in North Carolina
Lee S, Kakumanu M, Ponnusamy L, Vaughn M, Funkhouser S, Thornton H, Meshnick SR, Apperson CS.
Parasite Vectors, online before print, 2014 Dec 23;7(1):607.
The lone star tick (Amblyomma americanum) accounted for 95.0 and 92.9% of ticks submitted in 2011 (n=423) and 2012 (n=451), respectively. Specimens of American dog tick (Dermacentor variabilis), Gulf Coast tick (Amblyomma maculatum) and black-legged tick (Ixodes scapularis) were also identified. In both years of our study, 60.9% of ticks tested positive for 17-kDa. “Candidatus R. amblyommii”, identified in all four tick species, accounted for 90.2% (416/461) of the 23S-5S-positive samples and 52.9% (416/787) of all samples tested. Nucleotide sequence analysis of Rickettsia-specific 23S-5S IGS, ompA and gltA gene fragments indicated that ticks, principally A. americanum, contained novel species of Rickettsia. Other Rickettsiales, including Ehrlichia ewingii, E. chaffeensis, Ehrlichia sp. (Panola Mountain), and Anaplasma phagocytophilum, were infrequently identified, principally in A. americanum.
Geographic Expansion of Lyme Disease in the Southeastern United States, 2000–2014
Paul M. Lantos, Lise E. Nigrovic, Paul G. Auwaerter, Vance G. Fowler Jr., Felicia Ruffin, R. Jory Brinkerhoff, Jodi Reber, Carl Williams, James Broyhill, William K. Pan and David N. Gaines
Open Forum Infectious Diseases, Nov 2015; 2 (4).
The majority of Lyme disease cases in the United States are acquired on the east coast between northern Virginia and New England. In recent years the geographic extent of Lyme disease has been expanding, raising the prospect of Lyme disease becoming endemic in the southeast.
Bartonella is Everywhere, So Why Don’t We Know More About It?
By Stephanie Soucheray, North Carolina Health News, Chapel Hill, North Carolina
December 5, 2013
An N.C. State professor says Bartonella infection is one of the most important untold medical stories.
Rickettsiae and ehrlichiae within a city park: is the urban dweller at risk?
Blanton LS, Walker DH, Bouyer DH.
Vector Borne Zoonotic Dis. 2014 Feb;14(2):168-70.
A total of 273 ticks were collected during July, 2011. Amblyomma americanum was the predominant tick species, with 255 (93%) of those collected. The remaining 18 (7%) were Dermacentor variabilis. Ticks were separated and pooled into groups for further testing. Forty-two of the 43 (98%) A. americanum pools demonstrated molecular evidence for the presence of rickettsiae.
Human granulocytic anaplasmosis in the United States from 2008 to 2012: a summary of national surveillance data.
Dahlgren FS, Heitman KN, Drexler NA, Massung RF, Behravesh CB.
The American Journal of Tropical Medicine and Hygiene. 2015 Jul;93(1):66-72.
Cases were reported from 38 states and from New York City, with the highest incidence in Minnesota (IR = 97), Wisconsin (IR = 79), and Rhode Island (IR = 51). Thirty-seven percent of cases were classified as confirmed, almost exclusively by polymerase chain reaction.The reported case fatality rate was 0.3% and the reported hospitalization rate was 31%. IRs, hospitalization rates, life-threatening complications, and case fatality rates increased with age group. The IR increased from 2008 to 2012 and the geographic range of reported cases of anaplasmosis appears to have increased since 2000–2007.
Human infection with Ehrlichia muris–like pathogen, United States, 2007–2013
Hoang Johnson DK, Schiffman EK, Davis JP, Neitzel DF, Sloan LM, Nicholson WL, et al.
Emerging Infectious Diseases. 2015 Oct [Cited September 28, 2015].
During 2004–2013, blood samples from 75,077 patients from all 50 United States were tested by PCR from the groEL gene for Ehrlichia spp. and Anaplasma phagocytophilum. During 2007–2013, samples from 69 (0.1%) patients were positive for the EML pathogen; patients were from 5 states: Indiana (1), Michigan (1), Minnesota (33), North Dakota (3), and Wisconsin (31).
Detection of Borrelia, Ehrlichia, and Rickettsia spp. in ticks in northeast Missouri
Hudman DA, Sargentini NJ.
Ticks and Tick-borne Diseases, online first, 2016 Apr 20.
We evaluated Amblyomma americanum (lone star tick) and Dermacentor variabilis (American dog tick) in northeast Missouri for the presence of Borrelia, Ehrlichia, and Rickettsia bacteria. We collected actively questing ticks from four sites within Adair County, Missouri. A total of 15,162 ticks were collected, of which 13,980 were grouped in 308 pools (lone star ticks, 288 pools; American dog ticks, 20 pools) and tested for presence/absence of bacteria using polymerase chain reaction.Infection rates were calculated as the maximum likelihood estimation (MLE) with 95% confidence intervals (CI). Of the 308 pools tested, 229 (74.4%) were infected with bacteria and the overall MLE of the infection rate per 100 ticks was calculated as 2.9% (CI 2.61–3.21). Infection rates varied among life stages, 28.6% (CI 23.89–33.97) in adults, 7.0% (CI 5.10–9.86) in nymphs, and 1.0% (CI 0.75–1.20) in larvae.In the 116 adult lone star pools, infection rates were calculated for Borrelia lonestari (1.4%), Borrelia spp. (2.7%), Ehrlichia chaffeensis (6.1%), Ehrlichia ewingii (3.3%), Rickettsia amblyommii (18.3%), and Rickettsia montanensis (0.4%). Infection rates for the 52 nymphal lone star pools were calculated as B. lonestari (1.03%), Borrelia spp. (0.40%), E. chaffeensis (2.02%), E. ewingii (0.24%), and R. amblyommii (2.70%). In the 20 adult American dog tick pools, infection rates were determined as E. chaffeensis (9.47%), E. ewingii (5.47%), and R. montanensis (8.06%).
Geographic and genospecies distribution of Borrelia burgdorferi sensu lato DNA detected in humans in the United States
Kerry L Clark, Brian F Leydet and Clifford Threlkeld
Journal of Medical Microbiology, online ahead of print February 25, 2014.
The study findings suggest that human cases of Lyme disease in the southern U.S. may be more common than previously recognized, and may also be caused by more than one species of B. burgdorferi sensu lato. This study provides further evidence that B. burgdorferi sensu stricto is not the only species associated with signs and/or symptoms consistent with Lyme borreliosis in the USA.
Prevalence of Tick-Borne Pathogens in Host-Seeking Amblyomma americanum (Acari: Ixodidae) and Odocoileus virginianus (Artiodactyla: Cervidae) in Florida.
Sayler KA, Loftis AD, Beatty SK, Boyce CL, Garrison E, Clemons B, Cunningham M, Alleman AR, Barbet AF.
Journal of Medical Entomology, online first, 2016 Apr 26.
Amblyomma americanum (L.), the lone star tick, is an aggressive tick that is expanding its geographic range within the United States.In lone star ticks, 14.6, 15.6, and 57.1% were positive for E. chaffeensis, E. ewingii, and Rickettsia spp. DNA, respectively. Panola Mountain Ehrlichia or B. lonestari DNA were each detected in nearly 2% of tick specimens. In white-tailed deer, 7.3% were PCR positive for E. chaffeensis, 6.0% for E. ewingii, and 3.2% for rickettsial species. Approximately 45% of white-tailed deer specimens had antibodies to Ehrlichia spp., and <1% had antibodies to Borrelia burgdorferi.
Zoonotic Babesia microti in the northeastern U.S.: Evidence for the expansion of a specific parasite lineage
Goethert HK, Molloy P, Berardi V, Weeks K, Telford SR 3rd.
PLoS One. 2018 Mar 22;13(3):e0193837.
We conclude that a single B. microti genotype has expanded across the northeastern U.S. The biological attributes associated with this parasite genotype that have contributed to such a selective sweep remain to be identified.
Identification of Novel Viruses in Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis Ticks
Rafal Tokarz, Stephen Sameroff, Teresa Tagliafierro, Komal Jain, Simon H. Williams, D. Moses Cucura, Ilia Rochlin, Javier Monzon, Giovanna Carpi, Danielle Tufts, Maria Diuk-Wasser, Jory Brinkerhoff, W. Ian Lipkin
mSphere Mar 2018, 3 (2) e00614-17.
Ticks carry a wide range of known human and animal pathogens and are postulated to carry others with the potential to cause disease. Here we report a discovery effort wherein unbiased high-throughput sequencing was used to characterize the virome of 2,021 ticks, including Ixodes scapularis (n = 1,138), Amblyomma americanum (n = 720), and Dermacentor variabilis (n = 163), collected in New York, Connecticut, and Virginia in 2015 and 2016. We identified 33 viruses, including 24 putative novel viral species. The most frequently detected viruses were phylogenetically related to members of the Bunyaviridae and Rhabdoviridae families, as well as the recently proposed Chuviridae. Our work expands our understanding of tick viromes and underscores the high viral diversity that is present in ticks.
Impact of white-tailed deer on the spread of Borrelia burgdorferi
Roome A, Hill L, Al-Feghali V, Murnock CG, Goodsell JA, Spathis R, Garruto RM.
Medical and Veterinary Entomology, online first, 2016 Oct 4.
These data suggest that a mechanism in white-tailed deer may aid in clearing the pathogen from attached deer ticks, although white-tailed deer do contribute to the spatial distribution of deer tick populations and also serve as deadend host breeding sites for ticks.
A quantitative synthesis of the role of birds in carrying ticks and tick-borne pathogens in North America
Loss SR, Noden BH, Hamer GL, Hamer SA.
Oecologia, online first, 2016 Sep 26.
Birds play a central role in the ecology of tick-borne pathogens. They expand tick populations and pathogens across vast distances and serve as reservoirs that maintain and amplify transmission locally.
Wild Birds as Sentinels for Multiple Zoonotic Pathogens Along an Urban to Rural Gradient in Greater Chicago, Illinois.
Zoonoses and Public Health, online before print, February 22, 2012.
Hamer SA, Lehrer E, Magle SB.
Wild birds were captured using mist nets at five sites throughout greater Chicago, Illinois, and blood, faecal and ectoparasite samples were collected for diagnostic testing. A total of 289 birds were captured across all sites. A total of 2.8% of birds harboured Ixodes scapularis – the blacklegged tick – of which 54.5% were infected with the agent of Lyme disease.
Expanded geographic distribution and clinical characteristics of Ehrlichia ewingii infections, United States
Harris RM, Couturier BA, Sample SC, Coulter KS, Casey KK, Schlaberg R.
Emerging Infectious Diseases. 2016 May [cited April 20, 2016].
Ehrlichiosis is a bacterial zoonosis, spread through the bites of infected ticks, that is most commonly caused in the United States by infection with the bacterium Ehrlichia chaffeensis.We retrospectively reviewed samples from an 18-month study of ehrlichiosis in the United States and found that E. ewingii was present in 10 (9.2%) of 109 case-patients with ehrlichiosis, a higher rate of infection with this species than had previously been reported. Two patients resided in New Jersey and Indiana, where cases have not been reported. All patients with available case histories recovered.
Co-infection of Ticks: The Rule Rather Than the Exception
Moutailler S, Valiente Moro C, Vaumourin E, Michelet L, Tran FH, Devillers E, Cosson JF, Gasqui P, Van VT, Mavingui P, Vourc’h G, Vayssier-Taussat M.
PLOS Neglected Tropical Diseases, 10(3):e0004539. Online first, 2016 Mar 17.
Ticks transmit more pathogens than any other arthropod, and one single species can transmit a large variety of bacteria and parasites. Because co-infection might be much more common than previously thought, we evaluated the prevalence of 38 known or neglected tick-borne pathogens in Ixodes ricinus ticks. Our results demonstrated that co-infection occurred in almost half of the infected ticks, and that ticks could be infected with up to five pathogens.
Undetermined Human Ehrlichiosis and Anaplasmosis in the United States, 2008-2012: A Catch-All for Passive Surveillance
Dahlgren FS, Heitman KN, Behravesh CB.
The American Journal of Tropical Medicine and Hygiene, online first, 2015 Nov 30.
Human ehrlichiosis and anaplasmosis are potentially severe illnesses endemic in the United States. Several bacterial agents are known causes of these diseases: Ehrlichia chaffeensis, Ehrlichia ewingii, Ehrlichia muris-like agent, Panola Mountain Ehrlichia species, and Anaplasma phagocytophilum.
Increasing Incidence of Ehrlichiosis in the United States: A Summary of National Surveillance of Ehrlichia chaffeensis and Ehrlichia ewingii Infections in the United States, 2008-2012.
Heitman KN, Dahlgren FS, Drexler NA, Massung RF, Behravesh CB.
The American Journal of Tropical Medicine and Hygiene, online first, 2015 Nov 30.
Human ehrlichiosis is a potentially fatal disease caused by Ehrlichia chaffeensis and Ehrlichia ewingii. Cases of ehrlichiosis are reported to Centers for Disease Control and Prevention through two national surveillance systems: Nationally Notifiable Diseases Surveillance System (NNDSS) and Case Report Forms.
Human Babesiosis: Pathogens, Prevalence, Diagnosis and Treatment
Ord RL, Lobo CA.
Current Clinical Microbiology Reports. 2015 Dec;2(4):173-181.
Human babesiosis is a zoonotic disease caused by protozoan parasites of the Babesia genus, primarily in the Northeastern and Midwest USA due to Babesia microti and Western Europe due to Babesia divergens.
Virulence of the Lyme disease spirochete before and after the tick bloodmeal: a quantitative assessment
Irene N. Kasumba, Aaron Bestor, Kit Tilly and Patricia A. Rosa
Parasites & Vectors, 2016, 9:129, online first March 7, 2016.
Borrelia burgdorferi, the tick-transmitted agent of Lyme disease, adapts to different environments as it cycles between an arthropod vector and vertebrate host.Conditional priming of B. burgdorferi during tick feeding induces changes in addition to OspC that are required for infection of the mammalian host.
More stricken with Lyme disease in Franklin County, throughout Ohio
By Laura Arenschield, The Columbus Dispatch, Columbus, Ohio
January 5, 2016
Lyme disease cases are on the rise in Ohio, and this past year Franklin County residents bore the brunt of the bites.The number of people with the disease, spread by ticks, has steadily increased in the past six years, according to data from the Ohio Department of Health.From January through September 2015, 146 cases of Lyme disease were reported to the state agency. In all of 2014, 119 cases were reported. Ten years ago, 58 cases were reported.
Specifying Pathogen Associations of Amblyomma maculatum (Acari: Ixodidae) in Western Tennessee.
Mays SE, Houston AE, Trout Fryxell RT.
Journal of Medical Entomology, online first 2016 Jan 7.
Amblyomma maculatum Koch (Acari: Ixodidae) is established in western Tennessee, a region with increased risk for Rocky Mountain spotted fever and ehrlichiosis. This tick transmits Rickettsia parkeri to humans, likely contributing to cases of rickettsiosis in the region.The objective was to determine pathogen associations within questing and host-collected A. maculatum, and identify ecological factors associated with pathogen infection that may increase the effectiveness of surveillance methods. Of 265 ticks tested, 60 (22.6%) were infected with R. parkeri, and 15 (5.7%) with Candidatus Rickettsia andeanae, a Rickettsia of unknown pathogenicity. Two deer-collected ticks tested positive for Ehrlichia ewingii.
Rickettsia parkeri in Amblyomma americanum ticks, Tennessee and Georgia, USA.
Cohen SB, Yabsley MJ, Garrison LE, Freye JD, Dunlap BG, Dunn JR, et al.
Emerging Infectious Disease, 2009 Sep; [serial on the Internet].
To determine the geographic distribution of the newly recognized human pathogen Rickettsia parkeri, we looked for this organism in ticks from Tennessee and Georgia, USA. Using PCR and sequence analysis, we identified R. parkeri in 2 Amblyomma americanum ticks. This rickettsiosis may be underdiagnosed in the eastern United States.
Babesiosis Occurrence among the Elderly in the United States, as Recorded in Large Medicare Databases during 2006-2013.
Menis M, Forshee RA, Kumar S, McKean S, Warnock R, Izurieta HS, Gondalia R, Johnson C, Mintz PD, Walderhaug MO, Worrall CM, Kelman JA, Anderson SA.
PLoS One. 2015 Oct 15;10(10):e0140332.
A total of 10,305 elderly Medicare beneficiaries had a recorded babesiosis diagnosis during the eight-year study period, for an overall rate of about 5 per 100,000 persons. Study results showed a significant increase in babesiosis occurrence over time (p<0.05), with the largest number of cases recorded in 2013 (N = 1,848) and the highest rates (per 100,000) in five Northeastern states: Connecticut (46), Massachusetts (45), Rhode Island (42), New York (27), and New Jersey (14). About 75% of all cases were diagnosed from May through October. Babesiosis occurrence was significantly higher among males vs. females and whites vs. non-whites
Deciphering Babesia-Vector Interactions
Antunes S, Rosa C, Couto J, Ferrolho J, Domingos A.
Frontiers in Cellular and Infection Microbiology, online first 2017 Sep 29.
Understanding host-pathogen-tick interactions remains a vitally important issue that might be better understood by basic research focused on each of the dyad interplays.Pathogens gain access to either the vector or host during tick feeding when ticks are confronted with strong hemostatic, inflammatory and immune responses. A prominent example of this is the Babesia spp.—tick—vertebrate host relationship. Babesia spp. are intraerythrocytic apicomplexan organisms spread worldwide, with a complex life cycle. The presence of transovarial transmission in almost all the Babesia species is the main difference between their life cycle and that of other piroplasmida. With more than 100 species described so far, Babesia are the second most commonly found blood parasite of mammals after trypanosomes.
U.S. public’s experience with ticks and tick-borne diseases: Results from national HealthStyles surveys.
Hook SA, Nelson CA, Mead PS.
Ticks and Tick-borne Diseases. pii: S1877-959X(15)00054-0. Online first, 2015 Apr 14.
There were 4728 respondents in 2009, 4050 in 2011, and 3503 in 2012. Twenty-one percent of respondents reported that a household member found a tick on his or her body during the previous year; of these, 10.1% reported consultation with a health care provider as a result. Overall, 63.7% of respondents reported that Lyme disease (LD) occurs in the area where they live.
Filarial Nematode Infection in Ixodes scapularis Ticks Collected from Southern Connecticut
Pabbati Namrata, Jamie M. Miller, Madari Shilpa, Patlolla Raghavender Reddy, Cheryl Bandoski, Michael J. Rossi and Eva Sapi
Veterinary Sciences, 2014, 1(1), 5-15.
It was recently demonstrated that the lone star tick Amblyomma americanum could harbor filarial nematodes within the genus Acanthocheilonema. In this study, Ixodes scapularis (deer) ticks collected from Southern Connecticut were evaluated for their potential to harbor filarial nematodes.
Synanthropic rodents and their ectoparasites as carriers of a novel haemoplasma and vector-borne, zoonotic pathogens indoors.
Hornok S, Földvári G, Rigó K, Meli ML, Gönczi E, Répási A, Farkas R, Papp I, Kontschán J, Hofmann-Lehmann R.
Parasite & Vectors, online before print, 2015 Jan 15.
Fifty-two rodents (mainly house mice and brown rats) were caught alive in buildings and checked for blood-sucking ectoparasites; followed by molecular analysis of these, together with spleen samples, for the presence of vector-borne agents. Haemoplasma infection was significantly more prevalent among brown rats, than among house mice. A novel haemoplasma genotype (with only 92-93% similarity to Candidatus Mycoplasma turicensis and M. coccoides in its 16S rRNA gene) was detected in a harvest mouse and a brown rat. Sporadic occurrence of Rickettsia helvetica, Anaplasma phagocytophilum, Borrelia burgdorferi s.l. and Bartonella sp. was also noted in rodents and/or their ectoparasites. These results indicate that synanthropic rodents, although with low prevalence, may carry zoonotic and vector-borne pathogens indoors.
Impacts of misclassification on Lyme disease surveillance
Rutz H, Hogan B, Hook S, Hinckley A, Feldman K.
Zoonoses and Public Health. 2018 Sep 21.
In Maryland, Lyme disease (LD) is the most widely reported tickborne disease. All laboratories and healthcare providers are required to report LD cases to the local health department. Given the large volume of LD reports, the nuances of diagnosing and reporting LD, and the effort required for investigations by local health department staff, surveillance for LD is burdensome and subject to underreporting.
To determine the degree to which misclassification occurs in Maryland, we reviewed medical records for a sample of LD reports from 2009. We characterized what proportion of suspected and “not a case” reports could be reclassified as confirmed or probable once additional information was obtained from medical record review, explored the reasons for misclassification, and determined multipliers for a more accurate number of LD cases.
We reviewed medical records for reports originally classified as suspected (n = 44) and “not a case” (n = 92). Of these 136 records, 31 (23%) suspected cases and “not a case” reports were reclassified. We calculated multipliers and applied them to the case counts from 2009, and estimate an additional 269 confirmed and probable cases, a 13.3% increase.
Reasons for misclassification fell into three general categories: lack of clinical or diagnostic information from the provider; surveillance process errors; and incomplete information provided on laboratory reports. These multipliers can be used to calculate a better approximation of the true number of LD cases in Maryland, but these multipliers only account for underreporting due to misclassification, and do not account for cases that are not reported at all (e.g., LD diagnoses based on erythema migrans alone that are not reported) or for cases that are not investigated. Knowing that misclassification of cases occurs during the existing LD surveillance process underscores the complexities of LD surveillance, which further reinforces the need to find alternative approaches to LD surveillance.
Prevalence of Tick-Borne Pathogens in Northeast Missouri
Hudman DA, Sargentini NJ.
Missouri Medicine. 2018 Mar-Apr;115(2):162-168.
We evaluated Amblyomma americanum (lone star tick) and Dermacentor variabilis (American dog tick) in northeast Missouri for the presence of Borrelia, Ehrlichia, and Rickettsia bacteria and Heartland virus. We screened 436 individual adult lone star ticks (86% of all ticks collected) and infection rates were 6% for B. lonestari, 19% for E. chaffeensis, 3% for E. ewingii, 36% for R. amblyommatis, and 1% for R. montanensis.
In the 189 individual American dog ticks, infection rates were 19% for E. chaffeensis, 15% for E. ewingii, 4% for R. amblyommatis, and 5% for R. montanensis. In addition, we screened 20 pools of adults and 30 pools of nymphs for the Heartland virus which was not detected. Understanding the presence and epidemiology of these causative (E. chaffeensis and E. ewingii) and suspected (B. lonestari, R. amblyommatis, and R. montanensis) agents in Missouri should increase awareness of potential tick-borne disease in the medical community.
New Quest Diagnostics Data Shows Lyme Disease Prevalence Increasing and is Now Present in New U.S. States
Number of positive tests for Lyme disease increased significantly between 2016 and 2017.
Historically concentrated in Pennsylvania and New England states, Lyme disease has been detected in each of the 50 United States and the District of Columbia.
Outside of the northeastern U.S., California and Florida – states not historically associated with significant rates of Lyme disease – saw the largest absolute increases in positive Lyme disease test results. Notable increases also observed in Georgia, Arizona, Ohio, Texas, Tennessee and Virginia.
Press Release: Quest Diagnostics, Secaucus, New Jersey
July 31, 2018
The prevalence of Lyme disease is increasing in the United States, spiking significantly between 2016 and 2017, and has spread to all 50 United States and the District of Columbia, according to a new study released today by Quest Diagnostics (NYSE: DGX).
The number of positive Lyme disease test results is increasing. Based on more than six million de-identified laboratory test results conducted over the past seven years, the Quest Diagnostics study also found that outside of the northeastern U.S. which is historically associated with Lyme disease, California and Florida saw the largest absolute increases in positive test results. California found 483 infected patients in 2017, a 194.5 percent increase over 2015 levels. Florida found 501 infected patients in 2017, a 77 percent increase over 2015 levels. “Lyme disease is a bigger risk to more people in the United States than ever before,” said Harvey W. Kaufman, M.D., senior medical director for Quest Diagnostics and head of the company’s Health Trends research program. “Our data show that positive results for Lyme are both increasing in number and occurring in geographic areas not historically associated with the disease. We hypothesize that these significant rates of increase may reinforce other research suggesting changing climate conditions that allow ticks to live longer and in more regions may factor into disease risk.”
Increasing prevalence of Borrelia burgdorferi sensu stricto–infected blacklegged ticks in Tennessee Valley, Tennessee, USA, 2012–2017.
Hickling GJ, Kelly JR, Auckland LD, Hamer SA.
Emerging Infectious Diseases Volume 24, Number 9, September 2018 [cited July 27, 2018].
In 2017, we surveyed forests in the upper Tennessee Valley, Tennessee, USA.
We found Ixodes scapularis ticks established in 23 of 26 counties, 4 of which had Borrelia burgdorferi sensu stricto–infected ticks. Public health officials should be vigilant for increasing Lyme disease incidence in this region.
Using citizen science to describe the prevalence and distribution of tick bite and exposure to tick-borne diseases in the United States
Nieto NC, Porter WT, Wachara JC, Lowrey TJ, Martin L, Motyka PJ, Salkeld DJ.
PLoS One. 2018 Jul 12;13(7):e0199644. eCollection 2018.
Tick-borne pathogens are increasing their range and incidence in North America as a consequence of numerous factors including improvements in diagnostics and diagnosis, range expansion of primary vectors, changes in human behavior, and an increasing understanding of the diversity of species of pathogens that cause human disease. Public health agencies have access to human incidence data on notifiable diseases e.g., Borrelia burgdorferi, the causative agent of Lyme disease, and often local pathogen prevalence in vector populations. However, data on exposure to vectors and pathogens can be difficult to determine e.g., if disease does not occur. We report on an investigation of exposure to ticks and tick-borne bacteria, conducted at a national scale, using citizen science participation. 16,080 ticks were submitted between January 2016 and August 2017, and screened for B. burgdorferi, B. miyamotoi, Anaplasma phagocytophilum, and Babesia microti. These data corroborate entomologic investigations of tick distributions in North America, but also identify patterns of local disease risk and tick contact with humans throughout the year in numerous species of ticks and associated pathogens.
Ticks from cats in the United States: patterns of infestation and infection with pathogens
Susan E. Littlea, Anne W. Barretta, Yoko Nagamoria, Brian H. Herrin, Dorothy Normile, Kathleen Heaney, Rob Armstrong
Veterinary Parasitology, online first May 5, 2018.
Ticks are an important but under recognized parasitic threat to cats in many areas of the United States. To characterize the species and stages of ticks most commonly recovered from cats and determine the prevalence of disease agents in the ticks, we conducted a survey of ticks removed from cats at veterinary practices in 18 states from April 2016 – June 2017. A total of 796 ticks were submitted from 332 cats from 41 different veterinary practices. A single tick was submitted from the majority of cats, with a mean infestation intensity of 2.4 (range 1–46). The most common tick was Ixodes scapularis, accounting for 422/796 (53.0%) ticks submitted, followed by Amblyomma americanum (224/796; 28.1%) and Dermacentor variabilis (131/796; 16.5%); a few I. pacificus, I. banksi, D. occidentalis, A. maculatum, Rhipicephalus sanguineus, and Otobius megnini were also submitted. A majority of ticks were adults (593/796; 74.5%); females predominated in all adult tick submissions including I. scapularis (277/327; 84.7% female), A. americanum (66/128; 51.6% female), and D. variabilis (75/126; 59.5% female). Immature ticks included 186 nymphs and 17 larvae and were primarily I. scapularis and A. americanum. Adult I. scapularis were most reported to be attached to the dorsal head and neck; A. americanum to the abdomen and perianal region; and D. variabilis to the back and ear. Ticks were collected in every month; the largest number of submissions were in May and June (42.5% of ticks) and October and November (35.9% of ticks). Adults of I. scapularis were most commonly submitted October through December, A. americanum March through June, and D. variabilis May through July. Cats with ticks were predominantly male (58.8%) and altered (76.2%), and most reportedly spent >30% of time outdoors, although 64/294 (21.8%) for which lifestyle estimates were provided were reported to live primarily (=30% of time outside; n?=?54) or entirely (100%; n?=?10) indoors. Assay of ticks removed from cats revealed I. scapularis were infected with Borrelia burgdorferi (25.7%) and Anaplasma phagocytophilum (4.4%); A. americanum were infected with Ehrlichia chaffeensis (1.3%); and D. variabilis were infected with spotted fever group Rickettsia spp. (3.1%). No ticks in this study tested positive for Cytauxzoon felis. Pet cats, including those that live primarily indoors, are at risk of tick infestation, potentially exposed to tick-borne disease agents, and would benefit from routine tick control.
Vital Signs: Trends in Reported Vectorborne Disease Cases – United States and Territories, 2004-2016
Rosenberg R, Lindsey NP, Fischer M, et. al.
Morbidity and Mortality Weekly Report (MMWR) 2018 May 4;67(17):496-501.
A total 642,602 cases were reported. The number of annual reports of tickborne bacterial and protozoan diseases more than doubled during this period, from >22,000 in 2004 to >48,000 in 2016. Lyme disease accounted for 82% of all tickborne disease reports during 2004–2016. The occurrence of mosquito borne diseases was marked by virus epidemics. Transmission in Puerto Rico, the U.S. Virgin Islands, and American Samoa accounted for most reports of dengue, chikungunya, and Zika virus diseases; West Nile virus was endemic, and periodically epidemic, in the continental United States. Vectorborne diseases are a large and growing public health problem in the United States, characterized by geographic specificity and frequent pathogen emergence and introduction. Differences in distribution and transmission dynamics of tickborne and mosquitoborne diseases are often rooted in biologic differences of the vectors. To effectively reduce transmission and respond to outbreaks will require major national improvement of surveillance, diagnostics, reporting, and vector control, as well as new tools, including vaccines.
Occupational risk for personnel working in veterinary clinics through exposure to vectors of rickettsial pathogens
Escárcega-Ávila AM, de la Mora-Covarrubias A, Quezada-Casasola A, Jiménez-Vega F.
Ticks and Tick-borne Diseases, online first 2018 Oct 31.
It was established that grooming posed the highest risk for R. rickettsii exposure. The implementation of
appropriate management practices for zoonotic diseases is recommended to avoid health problems that
may be life threatening to personnel in veterinary clinics.
Regional prevalences of Borrelia burgdorferi, Borrelia bissettiae, and Bartonella henselae in Ixodes affinis, Ixodes pacificus and Ixodes scapularis in the USA
Ricardo G.Maggi, Marcée Toliver, Toni Richardson, Thomas Mather, Edward B. Breitschwerdt
Overall, 129/929 (13.9%) Ixodes ticks were PCR positive for Borrelia burgdorferi sensu stricto, 48/929 for B. bissettiae whereas 23/929 (2.5%) were PCR positive for a Bartonella henselae. Borrelia bissettiae or B. burgdorferi s.s. and B. henselae co-infections were found in I. affinis from North Carolina at a rate of 4.5%; in a single I. scapularis from Minnesota, but not in I. pacificus. For both bacterial genera, PCR positive rates were highly variable depending on geographic location and tick species, with Ixodes affinis (n = 155) collected from North Carolina, being the tick species with the highest prevalence’s for both Borrelia spp. (63.2%) and B. henselae (10.3%). Based on the results of this and other published studies, improved understanding of the enzooticcycle, transmission dynamics, and vector competence of Ixodes species (especially I. affinis) for transmission of Borrelia spp. and B. henselae should be a public health research priority.