The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Jennifer H. Mcquiston - One of the best experts on this subject based on the ideXlab platform.
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Epidemiology of Ehrlichiosis and Anaplasmosis among American Indians in the United States, 2000–2007
The American journal of tropical medicine and hygiene, 2012Co-Authors: Arianne M. Folkema, F. Scott Dahlgren, Robert C. Holman, James E. Cheek, Jennifer H. McquistonAbstract:Ehrlichiosis and Anaplasmosis infections among American Indians (AIs) have never been specifically examined, despite high rates of other tick-borne rickettsial diseases among AIs. The epidemiology of ehrlichiosis and Anaplasmosis among AIs was analyzed using the National Electronic Telecommunications System for Surveillance (NETSS), Case Report Forms (CRFs), and Indian Health Service (IHS) inpatient and outpatient visits. The 2000-2007 average annual ehrlichiosis and Anaplasmosis incidence among AIs reported to NETSS was almost 4-fold lower (4.0/1,000,000) than that using IHS data (14.9). American Indian cases reported from CRFs had a higher proportion of hospitalization (44%) compared with IHS (10%). American Indian incidence of ehrlichiosis and Anaplasmosis was higher and showed a different age and geographical distribution than other races. These results highlight the need to improve collaboration between the ehrlichiosis and Anaplasmosis surveillance systems for AIs so as to develop interventions that target the unique epidemiology and mitigate the burden of disease among this high-risk population.
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Increasing Incidence of Ehrlichia chaffeensis and Anaplasma phagocytophilum in the United States, 2000–2007
The American journal of tropical medicine and hygiene, 2011Co-Authors: F. Scott Dahlgren, Robert F Massung, Eric J. Mandel, John W. Krebs, Jennifer H. McquistonAbstract:Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic Anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and Anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and Anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.
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increasing incidence of ehrlichia chaffeensis and anaplasma phagocytophilum in the united states 2000 2007
American Journal of Tropical Medicine and Hygiene, 2011Co-Authors: Scott F Dahlgren, Robert F Massung, Eric J. Mandel, John W. Krebs, Jennifer H. McquistonAbstract:Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic Anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and Anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and Anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.
José De La Fuente - One of the best experts on this subject based on the ideXlab platform.
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Editorial: Tick-host-pathogen interactions
'Frontiers Media SA', 2019Co-Authors: Bonnet Sarah, Nijhof, Ard M., José De La FuenteAbstract:Ticks are important vectors of pathogens affecting human and animal health around the world. They act as vectors of several pathogens causing diseases of major concern including Lyme borreliosis, Anaplasmosis, rickettsiosis, ehrlichiosis, tularemia, and tick-borne encephalitis (TBE) in humans, and babesiosis, theileriosis, and Anaplasmosis in livestock. Therefore, a One Health approach is important for the effective prevention and control of tick-borne diseases (TBDs).Editorial on the Research Topic.Peer Reviewe
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Epidemiology and evolution of the genetic variability of Anaplasma marginale in South Africa.
Ticks and Tick-borne Diseases, 2014Co-Authors: Awelani M. Mutshembele, Alejandro Cabezas Cruz, Moses S. Mtshali, Oriel M.m. Thekisoe, Ruth C. Galindo, José De La FuenteAbstract:Bovine Anaplasmosis caused by infection of cattle with Anaplasma marginale has been considered to be endemic in South Africa, an assumption based primarily on the distribution of the tick vectors of A. marginale and serological studies on the prevalence of Anaplasmosis in Limpopo, Free State, and North West. However, molecular evidence of the distribution of Anaplasmosis has only been reported in the Free State province. In order to establish effective control measures for Anaplasmosis, epidemiological surveys are needed to define the prevalence and distribution of A. marginale in South Africa. In addition, a proposed control strategy for Anaplasmosis is the development of an A. marginale major surface protein la (MSP1a)-based vaccine. Nevertheless, regional variations of this gene would need to be characterized prior to vaccine development for South Africa. The objectives of the present study were therefore to conduct a national survey of the prevalence of A. marginale in South Africa, followed by an evaluation of the diversity and evolution of msp1a in South African strains of A. marginale. To accomplish these objectives, species-specific PCR was used to test 250 blood samples from cattle collected from all South African provinces (including 26 districts and municipalities), except the Free State province where similar studies were reported previously. The prevalence of A. marginale ranged from 65% to 100%, except in Northern Cape province where A. marginale was not detected. A correlation was found between the prevalence and genetic diversity of A. marginale MSP1a. Additionally, the genetic diversity of the A. marginale MSP1a was found to evolve under negative and positive selection, and 23 new tandem repeats in South Africa were shown to have evolved from the extant tandem repeat 4. Despite the MSP1a genetic variability, some types of tandem repeats were found to be conserved among the A. marginale strains, and low-variable peptides in MSP1a tandem repeats were subsequently identified. The results of this research confirmed that Anaplasmosis is endemic in South Africa. The results of the molecular characterization of the MSP1a can then be used as the basis for development of new and novel vaccines for Anaplasmosis control in South Africa.
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Current challenges in the diagnosis and control of bovine Anaplasmosis
The Bovine practitioner, 2012Co-Authors: Katherine M. Kocan, Johann F. Coetzee, José De La Fuente, Douglas L. Step, Edmour F. Blouin, Katharine M. Simpson, Emily Reppert, Melanie J. BoileauAbstract:Bovine Anaplasmosis, caused by the intracellular rickettsia Anaplasma marginale, continues to impact cattle production in the US. Control and management of bovine Anaplasmosis is influenced by our understanding of the complexity of this pathogen, interactions with both cattle and tick hosts, and the disease. A. marginale is maintained in nature through biological transmission by ticks and mechanical transmission by any means of blood transfer from infected to susceptible cattle. The major surface protein 5 (MSP5)-based cELISA, approved for use in the US and Canada, has proven to be a sensitive serologic test. However, more recently this test has been shown to be cross-reactive with closely related organisms, including A. phagocytophilum, because of the conservation of MSP5. Therefore, additional molecular tests may be required in some situations to confirm the identity of the infective agent. While tetracycline antimicrobials are approved by the US Food and Drug Administration for prevention or treatment of acute Anaplasmosis, no antimicrobials are labeled for elimination of persistent A. marginale infection. Administration of tetracyclines is an important means of preventing clinical Anaplasmosis, but does not prevent cattle from becoming infected with A. marginale. The mode of action of tetracycline is bacteriostatic rather than bactericidal, and its long-term use does not consistently clear cattle of persistent A. marginale infections. USDA approved vaccines for Anaplasmosis are currently unavailable. The challenges of vaccine development include the antigenic variation of A. marginale that occurs during persistent infections and the increased antigenic diversity of A. marginale strains, especially in areas of ongoing cattle movement. The overall goal of this and a previous overview is to summarize the current status of knowledge and research on bovine Anaplasmosis, and to provide veterinarians with answers to frequently asked questions.
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Current challenges of the management and epidemiology of bovine Anaplasmosis
The Bovine practitioner, 2010Co-Authors: Katherine M. Kocan, Johann F. Coetzee, José De La Fuente, Douglas L. Step, Edmour F. Blouin, Katharine M. Simpson, Suzanne G. Genova, Melanie J. BoileauAbstract:Bovine Anaplasmosis, caused by the intracellular rickettsia Anaplasma marginale, is endemic in several areas of the United States and has continued to impact cattle production. While considerable research has been done over the past several decades, control strategies for Anaplasmosis have advanced minimally since the first Anaplasmosis vaccine was marketed in the US in the 1960s. However, these research findings have continued to contribute to our overall understanding of the complexity of bovine Anaplasmosis. With the advent of molecular biology, host/pathogen interactions are currently better defined and the classification of Anaplasma has been reorganized to include several organisms in addition to those that are host-specific for ruminants. In this review, the current status of Anaplasmosis is discussed with the aim of providing insight to bovine practitioners on the future challenges for the management, diagnosis, and control of bovine Anaplasmosis. This review focuses on updated information on the classification of the genus Anaplasma and related organisms, the developmental cycle of A. marginale in cattle and ticks, the role of male ticks in transmission of Anaplasmosis, the diversity of A. marginale strains, the wildlife reservoirs of A. marginale, and the potential influence of climate change on the epidemiology of this serious disease. A second review will follow which focuses on current issues related to diagnosis and control of bovine Anaplasmosis. Overall, the goal of these reviews is to provide an understanding of the current status of research and knowledge of bovine Anaplasmosis and provide veterinarians answers to frequently asked questions.
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Genetic diversity of Anaplasma marginale strains from an outbreak of bovine Anaplasmosis in an endemic area.
Veterinary parasitology, 2008Co-Authors: Consuelo Almazán, Consuelo Alamzán, Citlaly Medrano, Martín Ortiz, José De La FuenteAbstract:Anaplasma marginale is a tick-borne pathogen of cattle that causes the disease bovine Anaplasmosis worldwide. Major surface proteins (MSPs) are involved in host-pathogen and tick-pathogen interactions and have been used as markers for the genetic characterization of A. marginale strains. A. marginale genotypes are highly variable in endemic areas worldwide. The genetic composition of A. marginale strains during Anaplasmosis outbreaks has been characterized in one study only which reported a single msp1alpha genotype in infected cattle. However, more information is required to characterize whether a single genotype is responsible for an Anaplasmosis outbreak or whether multiple genotypes can cause disease in naïve cattle within a single herd in endemic areas. The aim of this study was to characterize the genetic diversity of A. marginale strains from an outbreak of bovine Anaplasmosis in the State of Tamaulipas, Mexico. A. marginale genotypes were characterized at the molecular level using msp4 and msp1alpha gene sequences. The results revealed that several A. marginale genotypes are present in cattle during acute Anaplasmosis outbreaks, thus suggesting that mechanical transmission or stochastic biological transmission through equally efficient independent transmission events may explain A. marginale genotype frequency in a cattle herd during acute bovine Anaplasmosis outbreaks in endemic areas. The results reported herein corroborated the genetic heterogeneity of A. marginale strains in endemic regions worldwide. The development and implementation of Anaplasmosis control measures is dependent upon understanding the epidemiology of A. marginale in endemic regions, including the characterization of the genetic diversity of strains that produce outbreaks of bovine Anaplasmosis.
Scott F Dahlgren - One of the best experts on this subject based on the ideXlab platform.
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undetermined human ehrlichiosis and Anaplasmosis in the united states 2008 2012 a catch all for passive surveillance
American Journal of Tropical Medicine and Hygiene, 2016Co-Authors: Scott F Dahlgren, Kristen Nichols Heitman, Casey Barton BehraveshAbstract: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. Because more than one agent may be present in one area, cases of human ehrlichiosis and Anaplasmosis may be reported as "human ehrlichiosis/Anaplasmosis undetermined" when the available evidence does not suggest an etiology to the species level. Here, we present a brief summary of these undetermined cases with onset of symptoms from 2008 to 2012 reported to two passive surveillance systems in the United States. The reported incidence rate during this time was 0.52 cases per million person-years. Many cases (24%) had positive polymerase chain reaction results. Enhanced surveillance in an area where several of these etiologic agents are endemic may provide a better understanding of the epidemiology of ehrlichiosis and Anaplasmosis in the United States.
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human granulocytic Anaplasmosis in the united states from 2008 to 2012 a summary of national surveillance data
American Journal of Tropical Medicine and Hygiene, 2015Co-Authors: Scott F Dahlgren, Kristen Nichols Heitman, Naomi A Drexler, Robert F Massung, Casey Barton BehraveshAbstract:Abstract. Human granulocytic Anaplasmosis is an acute, febrile illness transmitted by the ticks Ixodes scapularis and Ixodes pacificus in the United States. We present a summary of passive surveillance data for cases of Anaplasmosis with onset during 2008–2012. The overall reported incidence rate (IR) was 6.3 cases per million person-years. 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. Our findings are consistent with previous case series and recent reports of the expanding range of the tick vector I. scapularis.
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increasing incidence of ehrlichia chaffeensis and anaplasma phagocytophilum in the united states 2000 2007
American Journal of Tropical Medicine and Hygiene, 2011Co-Authors: Scott F Dahlgren, Robert F Massung, Eric J. Mandel, John W. Krebs, Jennifer H. McquistonAbstract:Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic Anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and Anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and Anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.
Robert F Massung - One of the best experts on this subject based on the ideXlab platform.
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human granulocytic Anaplasmosis in the united states from 2008 to 2012 a summary of national surveillance data
American Journal of Tropical Medicine and Hygiene, 2015Co-Authors: Scott F Dahlgren, Kristen Nichols Heitman, Naomi A Drexler, Robert F Massung, Casey Barton BehraveshAbstract:Abstract. Human granulocytic Anaplasmosis is an acute, febrile illness transmitted by the ticks Ixodes scapularis and Ixodes pacificus in the United States. We present a summary of passive surveillance data for cases of Anaplasmosis with onset during 2008–2012. The overall reported incidence rate (IR) was 6.3 cases per million person-years. 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. Our findings are consistent with previous case series and recent reports of the expanding range of the tick vector I. scapularis.
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Increasing Incidence of Ehrlichia chaffeensis and Anaplasma phagocytophilum in the United States, 2000–2007
The American journal of tropical medicine and hygiene, 2011Co-Authors: F. Scott Dahlgren, Robert F Massung, Eric J. Mandel, John W. Krebs, Jennifer H. McquistonAbstract:Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic Anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and Anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and Anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.
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increasing incidence of ehrlichia chaffeensis and anaplasma phagocytophilum in the united states 2000 2007
American Journal of Tropical Medicine and Hygiene, 2011Co-Authors: Scott F Dahlgren, Robert F Massung, Eric J. Mandel, John W. Krebs, Jennifer H. McquistonAbstract:Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic Anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and Anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and Anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.
F. Scott Dahlgren - One of the best experts on this subject based on the ideXlab platform.
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Epidemiology of Ehrlichiosis and Anaplasmosis among American Indians in the United States, 2000–2007
The American journal of tropical medicine and hygiene, 2012Co-Authors: Arianne M. Folkema, F. Scott Dahlgren, Robert C. Holman, James E. Cheek, Jennifer H. McquistonAbstract:Ehrlichiosis and Anaplasmosis infections among American Indians (AIs) have never been specifically examined, despite high rates of other tick-borne rickettsial diseases among AIs. The epidemiology of ehrlichiosis and Anaplasmosis among AIs was analyzed using the National Electronic Telecommunications System for Surveillance (NETSS), Case Report Forms (CRFs), and Indian Health Service (IHS) inpatient and outpatient visits. The 2000-2007 average annual ehrlichiosis and Anaplasmosis incidence among AIs reported to NETSS was almost 4-fold lower (4.0/1,000,000) than that using IHS data (14.9). American Indian cases reported from CRFs had a higher proportion of hospitalization (44%) compared with IHS (10%). American Indian incidence of ehrlichiosis and Anaplasmosis was higher and showed a different age and geographical distribution than other races. These results highlight the need to improve collaboration between the ehrlichiosis and Anaplasmosis surveillance systems for AIs so as to develop interventions that target the unique epidemiology and mitigate the burden of disease among this high-risk population.
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Increasing Incidence of Ehrlichia chaffeensis and Anaplasma phagocytophilum in the United States, 2000–2007
The American journal of tropical medicine and hygiene, 2011Co-Authors: F. Scott Dahlgren, Robert F Massung, Eric J. Mandel, John W. Krebs, Jennifer H. McquistonAbstract:Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic Anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and Anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and Anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.