Littérature scientifique sur le sujet « Rickettsiosi, anaplasmosi »

The aim of the study was to assess the epizootiological situation on bacterial vector-borne infections in Caucasian Mineral Waters area of the Stavropol Territory over the period of 2018–2020.Materials and methods. 3494 specimens of ticks (473 pools), 257 specimens of small mammals, 9 regurgitates of birds of prey and mammals, 7 excreta samples of small mammals, and 2 water samples were tested. Laboratory research of the field material was carried out using molecular-genetic, serological, biological methods. Statistical analysis of laboratory results was conducted using Microsoft Excel 2010. The data were mapped using QGIS 2.18 software.Results and discussion. The study revealed that the 44.8 % of collected ticks were positive for tick-borne borreliosis, 21.5 % – for tick-borne rickettsiosis, 10.3% – for human granulocytic anaplasmosis, 2.7 % – for Q fever, 0.84 % – for tularemia. There has been an increase in the percentage of positives for tick-borne borreliosis agent samples (more than three times) and a decrease in this indicator for human granulocytic anaplasmosis (1.5 times) as compared with 2010–2012. Investigation of tick infection with the agents of Q fever and tick-borne rickettsioses has not been previously conducted in the region. During the period under review, 19 pools of ticks had mixed infection, which indicates that there are combined foci of bacterial natural-focal infections with vector-borne transmission in the recreation zone of the Stavropol Territory. This necessitates preventive measures and systematical epizootiological surveys in the Caucasian Mineral Waters region.

Along with a number of hosts, ticks are also capable of infesting snakes and transmitting rickettsiosis, anaplasmosis and ehrlichiosis. In the present study, ticks recovered from a Rat Snake Ptyas mucosa were collected and identified as Amblyomma gervaisi (previously known as Aponomma gervaisi). The case reports pertaining to observation of ticks (especially A. gervaisi) on reptile (snake) hosts are restricted to southern, eastern and western parts of India and the present study claims to be the first documented report of Amblyomma gervaisi ticks from Rat Snakes of northwestern Himalayan region.

Abstract Background Rickettsial diseases (RD) include Spotted Fever Group (SFG) Rickettsiosis, Ehrlichiosis, Anaplasmosis, Typhus Group (TG) and Rickettsialpox, among others. Doxycycline is the treatment of choice in all age groups; early treatment based on clinical diagnosis is important to prevent severe and fatal outcomes. SFG, Ehrlichiosis, and Anaplasmosis are nationally notifiable in the United States, but data on treatment patterns are not collected. Methods We conducted a retrospective analysis using Truven Health MarketScan® Commercial Claims and Encounters databases. We included any individual with an outpatient claim using an ICD-9/10-CM code for RD, who had one-year continuous pre- and 3 months post-diagnosis enrollment and pharmaceutical claim data. The first outpatient record with RD was considered the incident diagnosis, and those with an RD hospitalization in the prior 1 year were excluded. Epidemiologic characteristics, treatment patterns, and outcomes were summarized. Results 13,353 individuals were included; median age was 45 years (IQR: 28–55 years), 2,045 (15%) were under 18 years of age, and 51% were male. The most common diagnosis was SFG (7,133; 50%), followed by Ehrlichiosis (3,920; 30%), and Typhus (1,281; 10%); 36 individuals had >1 diagnosis. Over half (7,075; 53%) received doxycycline within 30 of the index date; of these, 3,634 (51%) received it within 14 days. The majority (5,369; 86%) were treated for at least 10 days at the recommended dose. The proportion with a pharmaceutical claim for doxycycline varied considerably across diagnoses and ranged from 24% for TG to 60% for SFG Rickettsiosis. Among the 6,278 (47%) without a claim for doxycycline, 2,185 (35%) were prescribed another antibiotic; 4,093 (28%) were not prescribed any antibiotic. Hospitalization within 30 days of the incident diagnosis was infrequent (149, 1.1%), and the majority were due to either SFR (40%) or ehrlichiosis (37%). No in-hospital deaths were recorded. Conclusion RD continues to be an important cause of disease in the outpatient population, but providers are still only prescribing the recommended treatment to about half of those in whom they suspect the disease. Continued education and increased awareness is critical to prevent severe outcomes from RD. Disclosures All authors: No reported disclosures.

Objective of the work was to carry out complex assessment of the current state of epizootic activity and epidemiological significance of the infectious disease natural foci in the Aleksandrovsk-Sakhalin territory of the Sakhalin Region. Trapped were 56 samples of small mammals in July, 2010; collected were 180 specimens of taiga tick imago, caught were 1000 specimens of mosquitoes. 223 samples of blood sera were taken from residents of the region. All the field data were tested to detect specific antibodies, antigens and genetic material of agents. Based on the results of epizootiological investigations, serological and molecular-genetic assays, demonstrated was the occurence of natural foci of leptospirosis, tularemia, tick-borne encephalitis, borreliosis, rickettsiosis, human granulocytic anaplasmosis, human monocytic ehrlichiosis, West Nile fever, Inco fever, Batai and Geto fevers, as well as HFRS with varying degree of activity manifestation in the territory of the region. Isolated was tick-borne encephalitis virus from mosquitoes.

Ticks are the most important vectors of human pathogens, leading to increased public health burdens worldwide. Tick-borne pathogens include viruses (e.g. tick-borne encephalitis and Powassan); bacteria, such as the causative agents of Lyme disease, spotted fever rickettsiosis and human anaplasmosis; and malaria-like protozoan parasites causing babesiosis. Tick-borne diseases are emerging due to the geographical expansion of their tick vectors, especially in the northern hemisphere. Two examples of this phenomenon are Ixodes scapularis and Amblyomma americanum, which have expanded their ranges in the USA in recent decades and are responsible for the continuous emergence of Lyme disease and human ehrlichiosis, respectively. This phenomenon is also occurring worldwide and is reflected by the increasing number of tick-borne encephalitis and haemorrhagic fever cases in Europe and Asia. In this review, we provide a concise synopsis of the most medically important tick-borne pathogen worldwide, with a particular emphasis on emerging public health threats.

The ectoparasite Ixodes ricinus is an important vector for many tick-borne diseases (TBD) in the northern hemisphere, such as Lyme borreliosis, rickettsiosis, human granulocytic anaplasmosis, or tick-borne encephalitis virus. As climate change will lead to rising temperatures in the next years, we expect an increase in tick activity, tick population, and thus in the spread of TBD. Consequently, it has never been more critical to understand relationships within the microbial communities in ticks that might contribute to the tick’s fitness and the occurrence of TBD. Therefore, we analyzed the microbiota in different tick tissues such as midgut, salivary glands, and residual tick material, as well as the microbiota in complete Ixodes ricinus ticks using 16S rRNA gene amplicon sequencing. By using a newly developed DNA extraction protocol for tick tissue samples and a self-designed mock community, we were able to detect endosymbionts and pathogens that have been described in the literature previously. Further, this study displayed the usefulness of including a mock community during bioinformatic analysis to identify essential bacteria within the tick.

Zoonoses are, in a broad sense, diseases transmitted to humans through direct or indirect contact with animals (vertebrates or invertebrates), their environment or by-products. There are different concepts, definitions and classifications of zoonoses according to different criteria. There are different concepts, definitions, and classifications of zoonoses following several criteria. Vectors are transmission vehicles that carry etiological agents between different animal species, including man, or between the environment and these species. The Republic of Panama is an interoceanic isthmus that meets all the basic conditions for the development of vector-borne diseases. This review provides a chronological analysis of the vectorial zoonoses related to companion animals or those that have a close relationship with humans. The history of studies on Trypanosomiasis, Leishmaniasis, Babesiosis, Hepatozoonosis, Rickettsiosis, Ehrlichiosis, Anaplasmosis, Bartonellosis, Borreliosis, Equine Encephalitis, Dirofilariasis and Dipylidiasis in Panama shows that environmental, socioeconomic, cultural, evolutive, investigative and educational factors have a direct influence on the success or failure in the control and prevention of these vectorial zoonoses. For this reason, major efforts are needed in relation to research and work that provide real data to support control programs for these diseases.

Aim of the present work is to improve knowledge on ecology of Ixodes ricinus ticks, on epidemiology of some zoonotic agent (Anaplasma phagocytophilum, Bartonella henselae, Bartonella clarridgeiae, Borrelia burgdorferi s.l., Richettsia helvetica, Rickettsia monacensis and Tick-borne encephalitis virus) and to define human risk to bite exposure. Study areas were some sites in the mountain habitats of the eastern Italian Alps and four public parks around Imola, province of Bologna. PCR were used for identification of all pathogens. Host seeking Ixodes ricinus ticks were harvested by dragging along transect of 100m. Density of ticks and association of prevalences of zoonotic inections in ticks with environmental variables (year, season, temperature, relative humidity, monthly rain, mean monthly temperature, vegetation cover, altitude) were evaluated using regression models. Presence of three zoonotic agents, Anaplasma phagocytophilum (Human Granulocitic Erlichiosis agent), Borrelia burgdorferi s.l. (Lyme disease agent) and Tick-borne encephalitis virus (TBE) was surveyed in the mountain habitats. In periurban parks Anaplasma phagocytophilum, Borrelia burgdorferi s.l., Bartonella henselae and B. clarridgeiae (cat scratch disease agents), Rickettsia helvetica and R. monacensis, two emerging rickettsial agents, were found. Acarological Risk, defined as probability of collecting at least one infected nymph along a 100m transect, were calculated as estimate of human risk of infection by each of the pathogens found. Results showed a high occurrence of Ixodes ricinus ticks in different habitats, with hot spots in some locality of mountain habitats, attributable to higher density of micromammals. Their abundance was also associated with season (higher abundance in spring and autumn) and vegetation cover. Borrelia burgdorferi s.l was widespread in wild and periurban habitats. A. phagocytophilum was present only in some localities in mountain habitats, with prevalence lower than 2%. B.henselae infection resulted surprisingly high in ticks from one of the public parks although it has typically a domestic cycle, with fleas (Ctenocephalides felis ) as vector and cats as reservoir. It can be therefore hypothesized that public parks may represent a link between the two cycles. Also the presence of R. helvetica and R. monacensis in public parks is an unexpected outcome: only few years ago these microorganismes were considered only as endosymbiont parasites of Ixodes ricinus and little is known about their epidemiology. The Acarological Risk values calculated show that public parks may represent a disregarded threat to public health, and that these areas should be surveyed, especially when high vegetation and animal densities may support increasing tick abundances.
Lo scopo della tesi è lo studio dell’ecologia di Ixodes ricinus e dell’epidemiologia di alcuni agenti zoonosici (Anaplasma phagocytophilum, Bartonella henselae, Bartonella clarridgeiae, Borrelia burgdorferi s.l., Richettsia helvetica, Rickettsia monacensis e il virus della Tick-borne encephalitis) e la stima del rischio per l’uomo di contrarre queste infezioni. Le aree di studio sono quelle tipicamente silvestri delle Prealpi del nord-est dell’Italia (nelle province di Verona, Vicenza, Treviso, Pordenone e Udine) e quelle periurbane di una cittadina del nord Italia (Imola, Bologna). In entrambe le indagini è stata stimata la densità delle ninfe di Ixodes ricinus (numero di ninfe per 100m2) raccolte mediante la metodica del dragging lungo transetti di 100m ed è stata valutata l’influenza delle variabili stagionali (temperatura e umidità relativa del transetto, temperature medie massime mensili, piovosità mensile, umidità relativa mensile) ed ambientali (tipo di vegetazione ed altitudine) mediante modelli di regressione binomiali negativi Nell’indagine svolta nelle aree silvestri la ricerca riguardante gli agenti patogeni si è concentrata sulla identificazione mediante Real-Time PCR di 3 patogeni: l’Anaplasma phagocytophilum (agente dell’Erlichiosi granulocitica umana), Borrelia burgdorferi s.l. (agente della malattia di Lyme) e del virus della Tick-borne encephalitis (TBE) mentre lo studio che ha coinvolto alcuni parchi della città di Imola ha evidenziato la presenza di Anaplasma phagocytophilum di Borrelia burgdorferi s.l., di Bartonella henselae e B. clarridgeiae, di Richettsia helvetica e R. monacensis, ritenute rickettsiosi emergenti. L’identificazione della presenza di tutti questi patogeni è stata effettuata con PCR classica. È stata quindi valutata mediante modelli di regressione logistica la relazione tra prevalenza e fattori di rischio quali i mesi di campionamento, anno e abbondanza di zecche. E’ stato inoltre quantificato il rischio per l’uomo chiamato anche rischio acarologico, definendolo come la probabilità di trovare almeno una ninfa infetta in 100m di transetto. I risultati ottenuti dimostrano una elevata diffusione della zecca Ixodes ricinus in habitat differenti, con dei picchi di densità in alcune aree probabilmente dovuti alle densità di micromammiferi presenti, che nei modelli di regressione non è stato possibile quantificare. Le indagini hanno confermato che l’abbondanza è influenzata notevolmente dalla stagione, con dei picchi primaverili ed autunnali, come in altre aree d’Europa, ma anche dalla tipologia di vegetazione. Riguardo agli aspetti epidemiologici, viene confermata l’endemia di Borrelia burgdorferi s.l. in habitat silvestri e habitat periurbani, mentre Anaplasma phagocytophilum è presente in focolai con prevalenze più basse del 2% solo in alcune province (Udine, Pordenone, Treviso). Di particolare interesse sono i risultati riguardanti la diffusione di B.henselae nelle zecche, poiché i il principale agente della CSD è generalmente associato ad un tipico ciclo domestico che ha come ospite reservoir il gatto e come vettore la pulce (Ctenocephalides felis). I parchi periurbani potrebbero quindi rappresentare un interfaccia tra cicli domestici e cicli selvatici. Lo stesso fenomeno non è ipotizzabile per B.clarridgeiae, data la scarsa prevalenza nelle zecche. Interessanti anche i risultati per Richettsia helvetica e R.monacensis, dimostrati essere da poco non solo endosimbionti di Ixodes ricinus, ma causa anche di zoonosi. Nonostante le disomogeneità evidenziate anche dai valori del rischio acarologico, il rischio di infettarsi per l’uomo in habitat periurbani non è trascurabile, considerando anche la maggior frequentazione per le attività ricreative rispetto ad habitat silvestri.

Dissertação de Mestrado Integrado em Medicina Veterinária
As doenças transmitidas por vectores são causadas por parasitas, bactérias ou vírus e são veiculadas pela picada de artrópodes (principalmente ixodídeos e mosquitos). Estas doenças afectam cães a nível mundial e a maioria delas têm potencial zoonótico. Nestas estão incluídas as doenças sob estudo: Erliquiose, Babesiose, Riquetsiose, Anaplasmose e Leishmaniose. A patogénese das doenças sob estudo, baseia-se fundamentalmente na resposta humoral exagerada e não protectora desenvolvida pelo hospedeiro, que provoca sintomas semelhantes aos de uma doença auto-imune. Isto é, ao contrário do que se podia pensar, não é o parasita em si que é responsável por todos os sintomas da doença, mas sim a resposta imunológica do hospedeiro à sua presença. No que respeita ao diagnóstico, os médicos veterinários podem ter a sua tarefa complicada devido à ausência de sintomas específicos e à presença de co-infecções (infecção por mais do que um parasita). A compreensão por parte do clínico, da patogenia e imunologia das doenças transmitidas por vectores, é uma ferramenta essencial para o diagnóstico rápido e preciso. Sob o ponto de vista zoonótico, se por um lado os canídeos actuam como sentinelas de doenças, por outro, são reservatórios de parasitas e importantes hospedeiros de transporte de vectores. Devido a isto um dos pontos fulcrais da prevenção destas hemoparasitoses é o controlo de vectores. Neste estudo foi realizado o rastreio de cinco doenças transmitidas por vectores, causadas pelos agentes: Ehrlichia canis, Anaplasma phagocytophilum, Rickettsia conorii, Babesia canis e Leishmania infantum. Este estudo incidiu sobre uma população de um canil de Setúbal, no qual foram testados 80 cães (29 machos e 51 fêmeas) escolhidos aleatoriamente. Os testes utilizados foram testes comerciais de imunofluorescência indirecta (IFI). Dos animais testados 58,75% dos animais encontravam-se infectados (20% co-infectados e 38,75% mono-infectados). As prevalências de anticorpos contra os 5 agentes foram: Rickettsia conorii (23,75%), Babesia canis (20%), Ehrlichia canis (16,25%), Leishmania infantum (16,25%) e Anaplasma phagocytophilum (12,5%).
ABSTRACT - Vector-borne diseases in kennel dogs, a study - Vector-borne diseases are caused by parasites, virus and bacteria, and transmitted through the bite of arthropods. These diseases have a great zoonotic potential and affect dogs worldwide. The five diseases studied (Ehrlichiosis, Babesiosis, Rickettsiosis, Anaplasmosis and Leishmaniasis) are included in this category of illness. The pathogenesis, it‘s based mainly on the humoral response developed by the host, that being exaggerated and not protective, causes symptoms similar to an autoimmune disease. Meaning, on the contrary to what might be thought, is not the parasite itself that is responsible for all the symptoms, but the host‘s immune response to their presence. Concerning the diagnosis, veterinarians can have their task complicated by the absence of specific symptoms and the presence of co-infection (infection for more than a parasite).The understanding of the clinical, the pathogenesis and immunology of vector-borne diseases, is an essential tool for rapid and accurate diagnosis. From the zoonotic point of view, dogs act as sentinels of disease, and are important reservoirs of parasites and carry vectors. Due to this, one of the key points for prevention of vector-borne diseases in animals and humans is vector control. In this study was performed the screening of five vector-borne diseases caused by the agents: Ehrlichia canis, Anaplasma phagocytophilum, Rickettsia conorii, Babesia canis and Leishmania infantum. This study focused on a population of a kennel of Setúbal, in which 80 dogs (29 males and 51 females), randomly chosen, were tested. The tests used were indirect fluorescence antibody (IFA) commercial. 58.75% of the animals tested animals were infected (20% co-infected and 38.75% single infections). The point prevalence for different pathogens was: Rickettsia conorii (23.75%), Babesia canis (20%), Ehrlichia canis (16.25%), Leishmania infantum (16.25%) and Anaplasma phagocytophilum (12.5%).

Rickettsioses are zoonoses caused by obligate Gram-negative intracellular bacteria of the order Rickettsiales, comprising (1) rickettsioses due to bacteria of the genus Rickettsia, including spotted fever groups and typhus groups (Rickettsiaceae), (2) ehrlichioses and anaplasmoses due to bacteria of the Anaplasmataceae, and (3) scrub typhus due to ...

Rickettsioses are mild to life-threatening zoonoses caused by obligate intracellular bacteria of the order Rickettsiales (family Rickettsiaceae). Arthropods, including ticks, fleas, and mites, are implicated as their vectors, reservoirs, or amplifiers. With an increasing number of new pathogens and recognition of new pathogenicity and affected geographical areas over the past few decades, there is a better understanding of the scope and importance of these pathogens, particularly as a paradigm to understanding emerging and remerging infections. The taxonomy has undergone numerous changes, with now three main groups classified as rickettsioses according to morphological, antigenic and metabolic characteristics: (1) Rickettsioses due to the bacteria of the genus Rickettsia, including the spotted fever group, typhus groups (Rickettsiaceae), (2) Ehrlichioses and Anaplasmoses due to bacteria of the Anaplasmataceae and (3) scrub typhus due to Orientia tsutsugamushi.