Ticks
Jerome Goddard in Public Health Entomology, 2022
Ehrlichiosis and anaplasmosis. Ehrlichia and Anaplasma organisms may be transmitted by ticks as well. They are rickettsia-like bacteria that primarily infect circulating leukocytes. The most common of them, Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (HME), occurs mostly in the central and southern United States, and infects mononuclear phagocytes in blood and tissues.12 There were 1,799 cases of HME in the United States in 2018.4 A new species of Ehrlichia causing human illness in Minnesota and Wisconsin has recently been recognized.13 Another, Anaplasma (formerly Ehrlichia) phagocytophilum, infects granulocytes and causes human granulocytic anaplasmosis (HGA); it is mostly reported from the upper Midwest and northeastern United States. There were 4,008 cases of HGA in the United States in 2018.4
Rifampicin (Rifampin)
M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson in Kucers’ The Use of Antibiotics, 2017
Ehrlichiae are rickettsia-like organisms transmitted by ticks. Recognized human pathogens are Ehrlichia chaffeensis, Anaplasma phagocytophilum (formerly E. phagocytophilia), and E. ewingii (Amsden et al., 2005; Dumler et al., 2007). These organisms are very sensitive to rifampicin in vitro (Brouqui and Raoult, 1990; Dumler and Bakken, 1995; Klein et al., 1997; Horowitz et al., 2001; Maurin et al., 2003; Branger et al., 2004), although rifampicin was inconsistently effective in eradicating organisms in experimental E. canis infection (Theodorou et al., 2013).
Severe Tick-Borne Infections and Their Mimics in the Critical Care Unit
Cheston B. Cunha, Burke A. Cunha in Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Ehrlichia chaffeensis, a gram-negative intracellular bacterium, is the etiologic agent of HME. Infection occurs from the bite of an infected lone star tick (Amblyomma americanum). The highest incidence is in South Central and southeastern United States; however, the disease can potentially occur in any state in which this tick species is endemic [3,14].
Advances in multiplex nucleic acid diagnostics for blood-borne pathogens: promises and pitfalls - an update
Published in Expert Review of Molecular Diagnostics, 2019
Robert Duncan, Elena Grigorenko, Carolyn Fisher, Donna Hockman, Bryan Lanning
Tick-borne pathogenic agents continue to emerge as blood safety threats. Babesia microti is well characterized and an FDA approved assay is available, however other recently emerged agents transmitted by the deer tick (Ixodes scapularis), increasingly demonstrate expanded geographic ranges, clinical case reports and more evidence of transmission by blood transfusion. During the last five years, several newly described tick-borne viral agents have also emerged and potentially may be transmitted by blood transfusion [2]. Examples of emerging tick-borne agents include the obligate intracellular Gram-negative bacterium, Anaplasma phagocytophilum, causing infections that range from asymptomatic to more severe disease and death in less than 1% of cases [3]; Ehrlichia chaffeensis, which causes human monocytic ehrlichiosis (HME), is primarily found in the southeastern US and is transmitted by the Lone Star tick, Amblyomma americanum [4]; of widespread concern the spirochete, Borrelia burgdorferi (Lyme Disease), is not typically a blood-borne agent due to its unique biology, however Borrelia miyamotoi, the agent of relapsing fever in the Northeast US, has been transfusion transmitted in a murine model [5].
How relevant are in vitro culture models for study of tick-pathogen interactions?
Published in Pathogens and Global Health, 2021
Cristiano Salata, Sara Moutailler, Houssam Attoui, Erich Zweygarth, Lygia Decker, Lesley Bell-Sakyi
The immunodominant surface proteins of the human pathogen Ehrlichia chaffeensis, and the closely related canine pathogen Ehrlichia canis, are encoded by multigene families. Protein expression studies of E. chaffeensis and E. canis grown in tick cell lines [44,139] confirmed previous observations on differential transcription of genes encoding their immunodominant outer membrane proteins in tick and mammalian hosts [140,141]. Two of the proteins encoded by members of the E. chaffeensis p28-Omp multigene family were predominantly expressed in infected canine macrophage (DH82) cultures, whereas a single, different p28-Omp protein was expressed in infected vector (AAE2) and non-vector (ISE6) tick cell lines [44,139]. Similarly, three of the proteins encoded by the E. canis p30-Omp multigene family were expressed in infected DH82 cultures, while the protein encoded by a single, different p30-Omp member was expressed in infected, non-vector (ISE6) tick cells.
Permethrin treated clothing to protect outdoor workers: evaluation of different methods for mosquito exposure against populations with differing resistance status
Published in Pathogens and Global Health, 2018
Stephanie L. Richards, Nwanne Agada, Jo Anne G. Balanay, Avian V. White
Commonly reported tick-borne diseases are Lyme disease, spotted fever group rickettsiosis, ehrlichiosis, and anaplasmosis [3]. The reason for the high number of tick-borne disease cases in recent years may be due to a lack of public knowledge of tick bite prevention methods [4]. A serosurvey done on United States National Park Service employees revealed that 22% of employees were seropositive from past exposure to spotted fever group rickettsiae, 3% were seropositive from past exposure to Ehrlichia chaffeensis, and 8% of employees were seropositive from past exposure to Anaplasma phagocytophylium [5]. Most of the participants spent 26% of their time working outdoors. This same study also looked at mosquito-borne pathogens and found that 1.5% were seropositive from past exposure to West Nile virus, 12.6% were seropositive from past exposure to La Crosse virus, and 2.2% were seropositive from a flavivirus (type not specified) [5]. A participant who was infected with La Crosse virus was reported to have spent 38% of his time working outdoors [5].
Related Knowledge Centers
- Amblyomma Americanum
- Bacteria
- Ehrlichiosis
- Rickettsiales
- Monocytotropic Ehrlichiosis