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Ticks
Published in Jerome Goddard, 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
Diagnostic Approach to Rash and Fever in the Critical Care Unit
Published in Cheston B. Cunha, Burke A. Cunha, Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Lee S. Engel, Charles V. Sanders, Fred A. Lopez
Over 90% of patients diagnosed correctly with Lyme disease have successful outcomes with treatment. The Ixodes tick is capable of transmitting other infectious agents, Anaplasma phagocytophilum and Babesia; thus, co-infections are possible. A small number of patients may develop post-treatment Lyme disease syndrome (PTLDS) [94]. No further serologic testing is recommended for PTLDS, as IgG and IgM antibodies can persist and remain detectible for years.
Ticks
Published in Gail Miriam Moraru, Jerome Goddard, The Goddard Guide to Arthropods of Medical Importance, Seventh Edition, 2019
Gail Miriam Moraru, Jerome Goddard
Anaplasma phagocytophilum infects granulocytes and causes human granulocytic anaplasmosis (HGA). For many years, this disease was called human granulocytic ehrlichiosis (HGE) and is often included in the older medical literature under that label. Complicating matters further, sometimes commercial laboratories may still refer to tests for HGA as human granulocytic ehrlichiosis tests. HGA is mostly reported from the upper midwestern and northeastern United States. There were 3656 cases of HGA reported to the CDC in 2015, a 30% increase over 2014.18 The case fatality rate is 0.3% but can be higher in older patients.31
Detection of Neoehrlichia mikurensis DNA in blood donors in southeastern Sweden
Published in Infectious Diseases, 2022
Lisa Labbé Sandelin, Jenny Olofsson, Conny Tolf, Louise Rohlén, Lars Brudin, Ivar Tjernberg, Per-Eric Lindgren, Björn Olsen, Jonas Waldenström
Although vector-borne infectious agents can be found in blood, they are generally not transmitted directly by blood contact, but by a vector, such as a tick or a mosquito [20]. As a result, vector-borne infections vary geographically depending on vector species distribution, competency, and available reservoirs [8,21]. Several tick-borne pathogens can potentially be transmitted through blood transfusion. Furthermore, many tick-borne microorganisms are located intracellularly, which is an excellent condition for transmission by transfusion [21]. Different tick-borne infections have different cell tropisms that affect prevalence and density in human blood, and thus the probability of transfusion-mediated transmission [22]. In the Northern Hemisphere, a limited number of tick-borne infections have been identified as TTIs [21,22]. The intraerythrocytic protozoan Babesia spp. is of greatest concern to recipient safety [1]. Of transfusion-transmitted tick-borne rickettsiae, Anaplasma phagocytophilum, which infects granulocytes and causes anaplasmosis, is most frequently reported [8,23].
Additional considerations for anti-tick vaccine research
Published in Expert Review of Vaccines, 2022
José de la Fuente, Marinela Contreras
Vaccination with Subolesin has shown protection against multiple tick species and pathogen infection/transmission [3,6]. The use of Subolesin-based vaccines alone or in combination with other antigens have reached 80–97% efficacy, similar or higher than that obtained with other tick antigens such as Bm86/Bm95, Metalloprotease, Ribosomal protein P0, Ferritin 2, and Aquaporin [6] (reviewed by [3]). Under field conditions, vaccination with the Subolesin-Anaplasma marginale Major surface protein 1a chimeric antigen resulted in reduction of tick infestations and pathogen infection/transmission in cattle and sheep [7]. These results support the possibility of combining tick and pathogen derived antigens for the control of tick infestations and TBD. Furthermore, Subolesin has shown efficacy in the control of cattle tick infestations with an oral vaccine formulation with heat inactivated Mycobacterium bovis [8] and the combination with Bm86 in a subcutaneous vaccine formulation.
Emerging and threatening vector-borne zoonoses in the world and in Europe: a brief update
Published in Pathogens and Global Health, 2019
Bacterial order Rickettsiales causes wide range of related diseases spread by ticks, fleas, chiggers and lice. Spreading abilities, morbidity and mortality rates of Rickettsiales are high. Typhus fever caused by Rickettsia prowazekii was classified as the category B on the list of bioterrorism agents [81]. The most common rickettsiosis in Europe is Mediterranean spotted fever caused by Rickettsia conorii. Even though the disease had been endemic to Southern Italy for many years [82], it has been spreading recently [83]. This infection may represent a severe threat, as its mortality rate is about 32% [84]. Anaplasmosis caused by Anaplasma phagophytophila has also a strongly increasing and widespread occurrence in Europe [85,86]. Recently, new human rickettsial infections have been recognized in Europe [82,87]. In general, rickettsioses occurrence increases in northern countries, which had been traditionally Rickettsia free [88]. It is supposed that this increasing occurrence is associated with the rise of temperature and decreasing number of frosty days [83,89,90]. Several rickettsial vaccines were developed; however, they were difficult, expensive and very hazardous to produce [91]. There is still no approved vaccine available yet [92].