331 research outputs found
Emerging tickborne diseases
No full textTuesday, March 21, at 1:00 p.m. ETInfections from tickborne diseases in the US are steadily increasing \u2014 and new tickborne diseases have been discovered in recent years. Ticks are vectors that can carry infectious agents such as bacteria, viruses, or parasites. When an infected tick bites a person or an animal, the tick\u2019s saliva transmits infectious agents that can cause illness. Some ticks can transmit multiple diseases. These \u201cco-infections\u201d pose challenges for diagnosing, treating and preventing tickborne diseases.The geographic ranges of ticks also are expanding. Ticks differ in their tolerance to heat, cold and aridity, making certain tick species more common than others in any given location in the United States. Different species transmit different diseases and this leads to differences in incidence of tickborne diseases by geographic region in the US.Rebecca Eisen, PhD, Research Biologist, Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC [\u201cExpanding Diversity and Distribution of Tickborne Diseases\u201d]; Christopher D. Paddock, MD, Medical Officer, Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC [\u201cTickborne Spotted Fevers \u2013 Old and New\u201d]; Gregory D. Ebel, ScD, Associate Professor, Department of Microbiology Immunology and Pathology, Director, Arthropod-Borne and Infectious Diseases Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University [\u201cEmerging Tickborne Viruses\u201c]; Bobbi Pritt, MD, MSc, DTM&H, Director, Clinical Parasitology Laboratory, Co-Director, Vector-borne Diseases Laboratory Services, Professor of Pathology and Laboratory Medicine, Division of Clinical Microbiology, Mayo Clinic [\u201cAdvances in Diagnosing Tickborne Diseases\u201d].Facilitated by: John Iskander, MD, MPH, Scientific Director, Public Health Grand Rounds; Phoebe Thorpe, MD, MPH, Deputy Scientific Director, Public Health Grand Rounds; Susan Laird, MSN, RN, Communications Director, Public Health Grand Rounds.Expanding Diversity and Distribution of Tickborne Diseases [PDF version of the PowerPoint presentation by Rebecca Eisen, p. 2-30] -- Tickborne Spotted Fevers \u2013 Old and New [PDF version of the PowerPoint presentation by P. Christopher D. Paddock, p. 31-45] -- Tickborne Viruses : Emerging Public Health Concern [PDF version of the PowerPoint presentation by Gregory D. Ebel, p. 46-64 ] -- Advances in Diagnosing Tickborne Diseases [PDF version of the PowerPoint presentation by Bobbi S. Pritt, p. 65-77].201
J Med Entomol
No full textIn recent decades, tickborne disease (TBD) cases and established populations of medically important ticks have been reported over expanding geographic areas, and an increasing number of tickborne bacteria, viruses, and protozoans have been recognized as human pathogens, collectively contributing to an increasing burden of TBDs in the United States. The prevention and diagnosis of TBDs depend greatly on an accurate understanding by the public and healthcare providers of when and where persons are at risk for exposure to human-biting ticks and to the pathogens these ticks transmit. However, national maps showing the distributions of medically important ticks and the presence or prevalence of tickborne pathogens are often incomplete, outdated, or lacking entirely. Similar deficiencies exist regarding geographic variability in host-seeking tick abundance. Efforts to accurately depict acarological risk are hampered by lack of systematic and routine surveillance for medically important ticks and their associated human pathogens. In this review, we: 1) outline the public health importance of tick surveillance; 2) identify gaps in knowledge regarding the distributions and abundance of medically important ticks in the United States and the presence and prevalence of their associated pathogens; 3) describe key objectives for tick surveillance and review methods appropriate for addressing those goals; and 4) assess current capacity and barriers to implementation and sustainability of tick surveillance programs.CC999999/ImCDC/Intramural CDC HHSUnited States
Variability in ornamentation of adult Dermacentor parumapertus Neumann (Acari: Ixodidae): implications for tick identification
No full textAbstract The hard tick Dermacentor parumapertus is an ectoparasite commonly found on hares and rabbits and occurs over much of the western United States. These ticks are rarely encountered except by hunters or scientists collecting rabbits for study. Herein we describe 74 adult D. parumapertus ticks (21F, 53M) removed from 8 black-tailed jackrabbits, Lepus californicus, in central Utah, and 13 adult D. parumapertus (7F, 6M) found on 4 L. californicus in western Texas. The Utah ticks were barely ornamented. Females displayed only slight gray ornamentation near the posterior edge of the scutum and whitish-gray spots distally on the femur of legs II, III, and IV; males were completely devoid of any ornamentation. In contrast, Texas specimens were richly ornamented in white, closely resembling D. variabilis. Females were brightly marked with white (not gray) on the scutum and had white spots distally on all femurs. Males from Texas were variously ornamented along the posterolateral margins of the scutum and displayed white spots distally on all femurs. Documentation of this variability in ornamentation in D. parumapertus is important, particularly as white-marked specimens can easily be confused with D. variabilis and since both species have been reported from rabbit hosts
Figure 1
No full text<p><b>A: <i>Bordetella pertussis</i> on Ciliated Cells of Bronchus.</b> Immunohistochemical localization of <i>B. pertussis</i> bacteria in the cilia of respiratory epithelium lining a bronchus of an infant who died from pertussis. Image courtesy of Christopher Paddock, M.D., Centers for Disease Control and Prevention. <b>B: Aggregates of Leukocytes in a Pulmonary Arteriole in Pertussis.</b> Pulmonary arteriole from an infant with fatal pertussis, showing intravascular aggregates of mixed leukocytes, comprising predominantly mature and band neutrophils, eosinophils, and monocytes. Image courtesy of Christopher Paddock, M.D., Centers for Disease Control and Prevention. <b>C: Drawing of <i>Bordetella pertussis</i> on Ciliated Cells in the Trachea.</b> Published over 100 Years Ago. Ciliated epithelium lining trachea of child dying in acute stage of whooping cough. Large numbers of minute bacilli present between the cilia. x1,000 <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003418#ppat.1003418-Mallory1" target="_blank">[27]</a>.</p
Clin Infect Dis
No full textBackground.Q fever is a worldwide zoonosis caused by Coxiella burnetii. In some persons, particularly those with cardiac valve disease, infection with C. burnetii can cause a life-threatening infective endocarditis. There are few descriptive analyses of Q fever endocarditis in the United States.Methods.Q fever case report forms submitted during 1999\u20132015 were reviewed to identify reports describing endocarditis. Cases were categorized as confirmed or probable using criteria defined by the Council for State and Territorial Epidemiologists (CSTE). Demographic, laboratory, and clinical data were analyzed.Results.Of 140 case report forms reporting endocarditis, 49 met the confirmed definition and 36 met the probable definition. Eighty-two percent were male and the median age was 57 years (range, 16\u201387 years). Sixty-seven patients (78.8%) were hospitalized, and 5 deaths (5.9%) were reported. Forty-five patients (52.9%) had a preexisting valvulopathy. Eight patients with endocarditis had phase I immunoglobulin G antibody titers >800 but did not meet the CSTE case definition for Q fever endocarditis.Conclusions.These data summarize a limited set of clinical and epidemiological features of Q fever endocarditis collected through passive surveillance in the United States. Some cases of apparent Q fever endocarditis could not be classified by CSTE laboratory criteria, suggesting that comparison of phase I and phase II titers could be reexamined as a surveillance criterion. Prospective analyses of culture-negative endocarditis are needed to better assess the clinical spectrum and magnitude of Q fever endocarditis in the United States.CC999999/Intramural CDC HHS/United State
Ticks Tick Borne Dis
No full textDermacentor andersoni, the Rocky Mountain wood tick, occurs predominantly in the northwestern United States and southwestern Canada. There are relatively few contemporary data to evaluate the occurrence of Rickettsia and Anaplasma species in D. andersoni in western North America, and even less information about these associations in the state of Washington, where this tick species is widely distributed and often bites humans. We used PCR assays to detect DNA of Rickettsia and Anaplasmataceae bacteria in 203 adult D. andersoni ticks collected from 17 sites in 9 counties of Washington between May 2012 and May 2015. Of these, 56 (27.6 %) were infected with a Rickettsia species and 3 (5.4 %) with a member of the Anaplasmataceae family. Rickettsia peacockii, R. bellii and R. rhipicephali were found in 17.7 %, 4.9 %, and 4.4 % of the Rickettsia positive ticks, respectively. Coinfections of R. bellii with R. peacockii or R. rhipicephali were identified in 6 ticks. Of the Anaplasmataceae-positive ticks, one was identified as being infected with Anaplasma phagocytophilum AP-Variant 1. No ticks were infected with a recognized human or animal pathogen, including R. rickettsii, A. phagocytophilum-ha, A. bovis, or A. marginale.CC999999/ImCDC/Intramural CDC HHSUnited States
Clin Infect Dis
No full textBackgroundRickettsia rickettsii, Rickettsia parkeri, and Rickettsia akari are the most common causes of spotted fever group rickettsioses indigenous to the United States. Infected patients characteristically present with a maculopapular rash, often accompanied by an inoculation eschar. Skin biopsy specimens are often obtained from these lesions for diagnostic evaluation. However, a species-specific diagnosis is achieved infrequently from pathologic specimens because immunohistochemical stains do not differentiate among the causative agents of spotted fever group rickettsiae, and existing polymerase chain reaction (PCR) assays generally target large gene segments that may be difficult or impossible to obtain from formalin-fixed tissues.MethodsThis work describes the development and evaluation of a multiplex real-time PCR assay for the detection of these 3 Rickettsia species from formalin-fixed, paraffin-embedded (FFPE) skin biopsy specimens.ResultsThe multiplex PCR assay was specific at discriminating each species from FFPE controls of unrelated bacterial, viral, protozoan, and fungal pathogens that cause skin lesions, as well as other closely related spotted fever group Rickettsia species.ConclusionsThis multiplex real-time PCR demonstrates greater sensitivity than nested PCR assays in FFPE tissues and provides an effective method to specifically identify cases of Rocky Mountain spotted fever, rickettsialpox, and R. parkeri rickettsiosis by using skin biopsy specimens.CC999999/Intramural CDC HHSUnited States
as a Paradigm for Multiple Causes of Tick‐Borne Spotted Fever in the Western Hemisphere
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