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1.
Parasitol Res ; 119(4): 1387-1392, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32211989

RESUMEN

Southern Germany is known as tick-borne encephalitis (TBE) risk area; however, the north of the country is almost free of human TBE cases. Due to its location in the transition zone between TBE risk areas and areas with only sporadic cases, Saxony is of importance in the surveillance of TBE. Roe deer (Capreolus capreolus), showing high seroprevalence of TBE virus (TBEV) antibodies, are considered to be sentinels for TBE risk assessment. Thus, roe deer could be used as indicators helping to better understand the focality of the TBEV in nature and as a possible source to isolate TBEV. Therefore, the aims of this study were to examine roe deer coats for the presence of ticks to establish the tick burden and to detect the TBEV in attached ticks. One hundred thirty-four roe deer coats were provided by hunters from the Hunting Association in Saxony (August 2017-January 2019). The coats were frozen at - 80 °C and after de-freezing examined on both sides-inside and outside. Attached and nonattached ticks were collected, morphologically identified and tested using real-time RT-PCR for the presence of TBEV. In total, 1279 ticks were found on 48 coats. The predominant species was Ixodes ricinus (99.76%; n = 1276). Three remaining specimens were Ixodes spp. (0.16%, 1 female and 1 nymph) and Dermacentor reticulatus (0.08%, 1 male). The average infestation rate was 26.7 (SD = 69.5), with maximum of 439 ticks per animal. Females were the dominant life stage of ticks (n = 536; 42%), followed by nymphs (n = 397; n = 31.1%), males (n = 175; 13.7%), and larvae (n = 168; 13.2%). Only half of collected ticks were attached (n = 662; 51.8%). TBEV was detected only in one tick out of 1279 tested ticks. It was a female infesting a roe deer from Saxon Switzerland-East Ore Mountain. The results show that the method used in this study is not sufficient as a sentinel marker to predict TBEV spreading in nature. Although previous studies demonstrated the usefulness of serological testing of roe deer in order to trace TBE-endemic regions, using ticks attached to them to get virus isolates is not productive.


Asunto(s)
Ciervos/parasitología , Dermacentor/clasificación , Encefalitis Transmitida por Garrapatas/veterinaria , Ixodes/clasificación , Carga de Parásitos/métodos , Animales , Dermacentor/virología , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Femenino , Alemania/epidemiología , Humanos , Ixodes/virología , Larva/virología , Masculino , Ninfa/virología , Estudios Seroepidemiológicos , Suiza/epidemiología
2.
Vet Radiol Ultrasound ; 58(1): 53-61, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27714889

RESUMEN

In vivo diagnosis of tick-borne encephalitis is difficult due to high seroprevalence and rapid viral clearance, limiting detection of antibodies in blood and cerebrospinal fluid. Magnetic resonance imaging (MRI) characteristics of tick-borne encephalitis have been reported, however MRI studies can also be negative despite the presence of neurologic signs. Magnetic resonance spectroscopy (1 H MRS) is an imaging method that provides additional information about the metabolic characteristics of brain tissues. The purpose of this retrospective cross-sectional study was to describe brain metabolites using short echo time single-voxel 1 H MRS in dogs with confirmed tick-borne encephalitis and compare them with healthy dogs. Inclusion criteria for the affected dogs were neurological symptoms suggestive of tick-borne encephalitis, previous endemic stay and tick-bite, diagnostic quality brain MRI and 1 H MRS studies, and positive antibody titers or confirmation of tick-borne encephalitis with necropsy. Control dogs were 10, clinically normal beagles that had been used in a previous study. A total of six affected dogs met inclusion criteria. All dogs affected with tick-borne encephalitis had 1 H MRS metabolite concentration alterations versus control dogs. These changes included mild to moderate decreases in N-acetyl aspartate and creatine peaks, and mild increases in glutamate/glutamine peaks. No lactate or lipid signal was detected in any dog. Myoinositol and choline signals did not differ between affected and control dogs. In conclusion, findings supported the use of 1 H MRS as an adjunctive imaging method for dogs with suspected tick-borne encephalitis and inconclusive conventional MRI findings.


Asunto(s)
Encéfalo/parasitología , Enfermedades de los Perros/diagnóstico por imagen , Encefalitis Transmitida por Garrapatas/veterinaria , Espectroscopía de Protones por Resonancia Magnética , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Estudios Transversales , Enfermedades de los Perros/parasitología , Perros , Encefalitis Transmitida por Garrapatas/diagnóstico por imagen , Encefalitis Transmitida por Garrapatas/parasitología , Femenino , Masculino , Valores de Referencia , Estudios Retrospectivos
3.
Acta Neurol Scand ; 125(5): 345-52, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21770904

RESUMEN

OBJECTIVES: Epilepsia partialis continua (EPC) is characterized by localized continuous jerks, from time to time with spreading Jacksonian seizures and, more rarely, secondarily generalized tonic-clonic seizures. EPC has numerous possible etiologies. In this paper we describe EPC in the tick-borne Russian spring-summer encephalitis (TBRSSE) and compare it with Rasmussen syndrome. METHODS AND METHODS: We included patients with EPC in TBRSSE (between 2003 and 2010). The diagnosis was verified by immunology (antibodies against TBRSSE virus). The patients were followed 1-7 (mean 3.4) years. RESULTS: We studied 10 patients (eight males, age 10-21 years) with MRI and video-EEG. Nine developed EPC after acute TBRSSE (meningoencephalitic form), and one had a tick bite without clinical symptoms of encephalitis, but with subsequent EPC. All patients came from Ural and Siberia. The onset was at age 4-14 (mean 8.6 years). The interval from onset of TBRSSE or the tick bite to seizure onset was 1 day-4 years. We identified three phases of clinical course EPC in TBRSSE: (i) acute (meningoencephalitic/encephalitic); (ii) development of EPC; and (iii) chronic EPC. The effect of antiepileptic drugs differed according to seizure types. CONCLUSION: EPC caused by TBRSSE is relatively frequent in the Eastern parts of the Russian Federation but not west of the Ural. Unlike Rasmussen encephalitis, EPC with TBRSSE does not progress even in the long term. It appears as disabling but not fatal condition with a time course where three phases can be distinguished.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/patogenicidad , Encefalitis Transmitida por Garrapatas/complicaciones , Encefalitis Transmitida por Garrapatas/fisiopatología , Epilepsia Parcial Continua/fisiopatología , Adolescente , Animales , Niño , Encefalitis Transmitida por Garrapatas/parasitología , Epilepsia Parcial Continua/diagnóstico , Epilepsia Parcial Continua/parasitología , Femenino , Humanos , Masculino , Adulto Joven
4.
Annu Rev Entomol ; 55: 95-110, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19961325

RESUMEN

Powassan virus (POW) (Flaviviridae: Flavivirus) is the cause of rare but severe neuroinvasive disease in North America and Russia. The virus is transmitted among small- and medium-sized mammals by ixodid ticks. Human infections occur via spillover from the main transmission cycle(s). Since the late 1990s, the incidence of human disease seems to be increasing. In addition, POW constitutes a genetically diverse group of virus genotypes, including Deer tick virus, that are maintained in distinct enzootic transmission cycles. This review highlights recent research into POW, focusing on virus genetics and ecology and human disease. Important directions for future research are also discussed.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/genética , Encefalitis Transmitida por Garrapatas/virología , Animales , Ecosistema , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Humanos , América del Norte/epidemiología
6.
Ticks Tick Borne Dis ; 9(2): 369-378, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29275872

RESUMEN

BACKGROUND: Information on the long-term outcome of tick-borne encephalitis (TBE) is limited. OBJECTIVES: To assess the frequency and severity of post-encephalitic syndrome (PES) at different time points after TBE, and to determine the parameters associated with unfavourable outcome. METHODS: Adult patients diagnosed with TBE in Slovenia in the period 2007-2012 were followed-up for 12 months and also examined 2-7 years after TBE. Each patient was asked to refer a person of similar age without a history of TBE to serve as control. RESULTS: A total of 420 patients and 295 control persons participated in the study. The proportion of patients with PES (defined as the presence of ≥ 2 subjective symptoms that newly developed or worsened since the onset of TBE and which had no other known medical explanation, and/or ≥ 1 objective neurological sign) was higher (P < 0.001) at the follow-up visit 6 months after the acute illness (127/304, 42%, 95% CI: 36-47%) than at 12 months (68/207, 33%, 95% CI: 26-40%); the proportion at 12 months was the same as at 2-7 years after TBE (137/420, 33%, 95% CI: 28-37%). However, the proportion of severe PES at the last two time points differed (9.7% vs 4.3%, P = 0.008). Multivariate logistic regression showed that unfavourable outcome at 6 months was associated with CSF leukocyte count (OR = 1.003, 95% CI: 1.001-1.005%, P = 0.017), at 12 months with the disease outcome at 6 months (OR = 115.473, 95% CI: 26.009-512.667%, P < 0.001), and at the final visit with disease outcome at 6 months (OR = 3.808, 95% CI: 1.151-12.593%, P = 0.028) and 12 months (OR = 26.740, 95% CI: 8.648-82.680%, P < 0.001). Unspecific symptoms that occurred within the four weeks before the final examination were more frequent and more constant in patients than in the control group. CONCLUSIONS: The frequency of PES diminished over time and stabilized 12 months after the acute illness, whereas the severity of PES continued to decline. Unfavourable outcomes at 12 months and at the final visit were strongly associated with the presence of PES at previous time points.


Asunto(s)
Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/fisiopatología , Adulto , Estudios de Casos y Controles , Encefalitis Transmitida por Garrapatas/parasitología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Eslovenia/epidemiología
7.
Ticks Tick Borne Dis ; 9(1): 97-103, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29030314

RESUMEN

This study investigated the geographical distribution of Ixodes ricinus and prevalence of the tick-borne encephalitis virus (TBEV) in northern Norway. Flagging for questing I. ricinus ticks was performed in areas ranging from Vikna in Nord-Trøndelag County, located 190km south of the Arctic Circle (66.3°N), to Steigen in Nordland County, located 155km north of the Arctic Circle. We found that ticks were abundant in both Vikna (64.5°N) and Brønnøy (65.1°N). Only a few ticks were found at locations ∼66°N, and no ticks were found at several locations up to 67.5°N. Real-time PCR (RT-PCR) analyses of the collected ticks (nymphs and adults) for the presence of TBEV revealed a low prevalence (0.1%) of TBEV among the nymphs collected in Vikna, while a prevalence of 0% to 3% was found among nymphs collected at five locations in Brønnøy. Adult ticks collected in Vikna and Brønnøy had higher rates of TBEV infection (8.6% and 0%-9.0%, respectively) than the nymphs. No evidence of TBEV was found in the few ticks collected further north of Brønnøy. This is the first report of TBEV being detected at locations up to 65.1°N. It remains to be verified whether viable populations of I. ricinus exist at locations north of 66°N. Future studies are warranted to increase our knowledge concerning tick distribution, tick abundance, and tick-borne pathogens in northern Norway.


Asunto(s)
Distribución Animal , Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Ixodes/fisiología , Ixodes/virología , Animales , Regiones Árticas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Femenino , Ixodes/crecimiento & desarrollo , Masculino , Noruega/epidemiología , Ninfa/virología , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa , Estaciones del Año
8.
Ticks Tick Borne Dis ; 9(2): 146-150, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28918352

RESUMEN

The 19th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE) - a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians and epidemiologists-was held under the title "TBE in a changing world". Key topics within virology, current epidemiological developments and investigations, expansion of risk areas, clinical aspects and cases, traveling and mobility, vaccination rates, and latest news on vaccination were presented and extensively discussed. Over the past four decades, TBE has become a growing public health challenge in Europe and parts of Asia. It may be considered a complex eco-epidemiological system, characterized by an intricate interplay between the virus, ticks and tick hosts on the one hand and human exposure strongly influenced by socioeconomic conditions on the other hand. Although the facts are simple - vaccination is the best prevention - the socioeconomic conditions keep changing, and with them the ability or willingness of people to get vaccinated.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Encefalitis Transmitida por Garrapatas , Garrapatas/virología , Animales , Encefalitis Transmitida por Garrapatas/diagnóstico , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Encefalitis Transmitida por Garrapatas/transmisión , Europa (Continente)
9.
Ticks Tick Borne Dis ; 9(1): 120-125, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28988602

RESUMEN

OBJECTIVES: Tick-borne encephalitis virus (TBEV) is a zoonotic agent causing severe encephalitis. In 2016, in Northeastern France, we faced a TBEV infection increase, leading to a warning from the Regional Health Agency. Here, we report the confirmed TBE cases diagnosed between January 2013 and December 2016, with particular emphasis on the year 2016. METHODS: A total of 1643 blood and cerebrospinal fluid (CSF) samples from everywhere in France, corresponding to 1460 patients, were prospectively tested for anti-TBEV-specific IgM and IgG antibodies by ELISA. Additional 39 blood and CSF samples from patients with suspected Lyme neuroborreliosis were retrospectively investigated. RESULTS: The TBEV seropositivity rate was estimated to 5.89% and 54 patients were diagnosed as TBE-confirmed cases. A significant increase in TBE cases was observed during the year 2016 with 29 confirmed cases, instead of a mean of eight cases during the three previous years (p=0.0006). Six imported cases and 48 autochthonous cases, located in the Alsace region (n=43) and in the Alpine region (n=5) were reported. Forty-six patients experienced neurological impairment. Nine patients showed an incomplete recovery at last follow-up (from 15days to eight months post-infection). TBE diagnosis was performed earlier for patients taken in charge in the Alsace region than those hospitalized elsewhere in France (p=0.0087). Among the 39 patients with suspected Lyme neuroborreliosis retrospectively investigated, one showed a TBEV recent infection. CONCLUSION: The TBE increase that occurred in France in 2016 highlights the need to improve our knowledge about the true burden of TBEV infection and subsequent long-term outcomes.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Encefalitis Transmitida por Garrapatas/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antibacterianos/sangre , Niño , Encefalitis Transmitida por Garrapatas/sangre , Encefalitis Transmitida por Garrapatas/parasitología , Ensayo de Inmunoadsorción Enzimática , Femenino , Francia/epidemiología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estudios Retrospectivos , Estaciones del Año , Adulto Joven
10.
Artículo en Inglés | MEDLINE | ID: mdl-29617333

RESUMEN

During 1999­2012, 77% of the cases of tick-borne encephalitis (TBE) were recorded in two out of 16 Polish provinces. However, historical data, mostly from national serosurveys, suggest that the disease could be undetected in many areas. The aim of this study was to identify which routinely-measured meteorological, environmental, and socio-economic factors are associated to TBE human risk across Poland, with a particular focus on areas reporting few cases, but where serosurveys suggest higher incidence. We fitted a zero-inflated Poisson model using data on TBE incidence recorded in 108 NUTS-5 administrative units in high-risk areas over the period 1999­2012. Subsequently we applied the best fitting model to all Polish municipalities. Keeping the remaining variables constant, the predicted rate increased with the increase of air temperature over the previous 10­20 days, precipitation over the previous 20­30 days, in forestation, forest edge density, forest road density, and unemployment. The predicted rate decreased with increasing distance from forests. The map of predicted rates was consistent with the established risk areas. It predicted, however, high rates in provinces considered TBE-free. We recommend raising awareness among physicians working in the predicted high-risk areas and considering routine use of household animal surveys for risk mapping.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Geografía/estadística & datos numéricos , Medición de Riesgo/métodos , Medición de Riesgo/estadística & datos numéricos , Animales , Humanos , Incidencia , Modelos Estadísticos , Polonia/epidemiología , Encuestas y Cuestionarios
11.
Parasit Vectors ; 10(1): 466, 2017 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-29017579

RESUMEN

BACKGROUND: Ixodes ricinus is a three-host tick, a principal vector of Borrelia burgdorferi (s.l.) and one of the main vectors of tick-borne encephalitis (TBE) virus. Iceland is located in the North Atlantic Ocean with subpolar oceanic climate. During the past 3-4 decades, average temperature has increased, supporting more favourable conditions for ticks. Reports of I. ricinus have increased in recent years. If these ticks were able to establish in a changing climate, Iceland may face new threats posed by tick-borne diseases. METHODS: Active field surveillance by tick flagging was conducted at 111 sites around Iceland from August 2015 to September 2016. Longworth mammal traps were used to trap Apodemus sylvaticus in southwestern and southern Iceland. Surveillance on tick importation by migratory birds was conducted in southeastern Iceland, using bird nets and a Heligoland trap. Vulpes lagopus carcasses from all regions of the country were inspected for ticks. In addition, existing and new passive surveillance data from two institutes have been merged and are presented. Continental probability of presence models were produced. Boosted Regression Trees spatial modelling methods and its predictions were assessed against reported presence. RESULTS: By field sampling 26 questing I. ricinus ticks (7 males, 3 females and 16 nymphs) were collected from vegetation from three locations in southern and southeastern Iceland. Four ticks were found on migratory birds at their arrival in May 2016. A total of 52 A. sylvaticus were live-trapped but no ticks were found nor on 315 V. lagopus carcasses. Passive surveillance data collected since 1976, reports further 214 I. ricinus ticks from 202 records, with an increase of submissions in recent years. The continental probability of presence model correctly predicts approximately 75% of the recorded presences, but fails to predict a fairly specific category of recorded presence in areas where the records are probably opportunistic and not likely to lead to establishment. CONCLUSIONS: To the best of our knowledge, this study represents the first finding of questing I. ricinus ticks in Iceland. The species could possibly be established locally in Iceland in low abundance, although no questing larvae have yet been detected to confirm established populations. Submitted tick records have increased recently, which may reflect an increase in exposure, or in interest in ticks. Furthermore, the amount of records on dogs, cats and humans indicate that ticks were acquired locally, presenting a local biting risk. Tick findings on migratory birds highlight a possible route of importation. Obtaining questing larvae is now a priority to confirm that I. ricinus populations are established in Iceland. Further surveys on wild mammals (e.g. Rangifer tarandus), livestock and migratory birds are recommended to better understand their role as potential hosts for I. ricinus.


Asunto(s)
Monitoreo Epidemiológico , Ixodes/fisiología , Infestaciones por Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Animales , Aves/parasitología , Borrelia burgdorferi/aislamiento & purificación , Gatos , Perros , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Femenino , Humanos , Islandia/epidemiología , Ixodes/parasitología , Masculino , Infestaciones por Garrapatas/veterinaria , Enfermedades por Picaduras de Garrapatas/parasitología , Enfermedades por Picaduras de Garrapatas/transmisión
12.
Ticks Tick Borne Dis ; 7(5): 911-914, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27189584

RESUMEN

The 18th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE)-a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians and epidemiologists-was held under the title 'Tick-borne encephalitis-still on the map'. The conference agenda was divided into six sessions: 'National Implementation of EU notifiable disease status', 'Virology', 'Epidemiology and Risk areas & Poster Walk Epidemiological Update', 'Clinic', 'Environmental Factors' and 'New Findings and Diagnosis'. Key topics such as 'TBE as a notifiable disease-results of the third European survey', 'TBE vaccines over the years', 'Overview of flaviviruses', 'TBE virus phylogenetics', 'Current epidemiological developments and investigations', 'Clinical aspects', 'TBE in veterinary medicine', 'Laboratory diagnostic', 'Occupational risk', 'Allergy, obesity, and vaccination' were presented and extensively discussed.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas , Encefalitis Transmitida por Garrapatas , Animales , Virus de la Encefalitis Transmitidos por Garrapatas/clasificación , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/parasitología , Encefalitis Transmitida por Garrapatas/virología , Enfermedades Endémicas , Humanos , Factores de Riesgo , Viaje , Vacunación , Vacunas Virales
13.
Adv Clin Exp Med ; 24(2): 361-71, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25931371

RESUMEN

The psychopathological symptoms occurring in the course of diseases associated with infections are often initially isolated and non-characteristic, and may cause diagnostic difficulties. Moreover, such disorders tend to be less responsive to psychiatric management. Among possible causes such as trauma, neoplasm and vascular changes, inflammatory changes of the brain as a result of a viral infection should also be considered. There were 452 registered cases of viral encephalitis in Poland in 2010, and although not very prevalent they remain a severe and life-threatening condition. What is more, the frequently occurring neurological and psychiatric complications of viral encephalitis often result in permanent disabilities, causing a significant decrease in the quality of life. This article presents the three types of encephalitis that are most prevalent among immunocompetent patients in Poland, i.e. herpes simplex encephalitis (HSE), tick-borne encephalitis (TBE) and herpes zoster encephalitis (HZE). The psychopathology of the acute phase of the infection, the residual symptoms, features apparent in imaging studies and some neuropathological aspects are also presented. The paper also focuses on psychiatric aspects of the diagnostics and treatment of the described conditions. The clinical pictures of these infections are quite specific, although they cover a wide range of symptoms, and these characteristic features are described. The aim of this review is also to show the significance of thorough diagnostics and a multidisciplinary approach to patients with viral CNS infections.


Asunto(s)
Encefalitis por Herpes Simple/psicología , Encefalitis por Varicela Zóster/psicología , Inmunocompetencia , Encefalitis por Herpes Simple/diagnóstico , Encefalitis por Herpes Simple/epidemiología , Encefalitis por Herpes Simple/inmunología , Encefalitis por Herpes Simple/terapia , Encefalitis por Herpes Simple/virología , Encefalitis Transmitida por Garrapatas/diagnóstico , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/inmunología , Encefalitis Transmitida por Garrapatas/parasitología , Encefalitis Transmitida por Garrapatas/psicología , Encefalitis Transmitida por Garrapatas/terapia , Encefalitis por Varicela Zóster/diagnóstico , Encefalitis por Varicela Zóster/epidemiología , Encefalitis por Varicela Zóster/inmunología , Encefalitis por Varicela Zóster/terapia , Encefalitis por Varicela Zóster/virología , Humanos , Polonia/epidemiología , Prevalencia , Pronóstico
14.
Trans R Soc Trop Med Hyg ; 94(3): 238-42, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10974986

RESUMEN

Experiments, using the capture-mark-release-recapture technique inside large nets, were carried out in Chiang Mai, northern Thailand, to examine heterogeneity in the host preference of Japanese encephalitis (JE) vectors. A significantly higher proportion of the vector species that were initially attracted to a cow fed when released into a net with a cow than when released into a net containing a pig. However, Culex vishnui individuals that had been attracted to a pig had a higher feeding rate in a net containing a pig rather than a cow. When mosquitoes were given a choice by being released into a net containing both animals, they exhibited a tendency to feed on the host to which they had originally been attracted. This feeding preference was, however, not shown by the offspring of pig-fed individuals. We have therefore shown evidence of physiological/behavioural conditioning in the host preference of JE vectors rather than genetic variability. Our results suggest that effective control of JE might be achieved by increasing the availability of cows (the dead-end hosts of JE virus) to deflect the vectors from pigs (the amplifying host). The behavioural imprinting which we have found would tend to re-inforce the initial tendency of the vectors to bite cows.


Asunto(s)
Culex/fisiología , Encefalitis Transmitida por Garrapatas/parasitología , Insectos Vectores/fisiología , Animales , Bovinos/parasitología , Virus de la Encefalitis Japonesa (Especie) , Encefalitis Transmitida por Garrapatas/epidemiología , Conducta Alimentaria , Femenino , Interacciones Huésped-Parásitos , Humanos , Porcinos/parasitología , Tailandia/epidemiología
15.
Cent Eur J Public Health ; 3(1): 33-7, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7787824

RESUMEN

Based on reports of the national epidemiological service on tick-borne encephalitis (TBE) morbidity in 1953-1987, data in the literature, and results of the author's own field research on the occurrence of the common tick, Ixodes ricinus, foci of this disease have been identified on the territory of Czechoslovakia. In Bohemia a significant focus of TBE in the Central Bohemian Region is located in the Krivoklát area with forests and in the Berounka, mid-Vltava, and lower-Sázava river basins, in the Brdy area and the Czech Karst continuing southwards via the Vltava basin to foci in the South Bohemian region in the districts of Písek and Ceské Budejovice and west of the Berounka river basin to a focus in the central part of the West Bohemian region. In the North Bohemian and East Bohemian regions only smaller isolated foci of TBE were detected. In Moravia foci of TBE are in the districts of Opava and Bruntál in the North Moravian region and in the central and southern areas of the South Moravian region. The foci in Bohemia are isolated from foci in neighboring countries, those of Moravia are connected with foci in Poland and Austria. On the territory of the Czech Republic foci of TBE are found in localities of pristine oakwood agglomerations. Original beechwood agglomerations even when located below the upper limit of occurrence of the common tick, i.e. less than 700 meters above sea level, do not offer favourable conditions for this arthropod and they do not harbour natural foci of TBE.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Encefalitis Transmitida por Garrapatas/epidemiología , Garrapatas , Árboles/parasitología , Animales , República Checa/epidemiología , Ecosistema , Encefalitis Transmitida por Garrapatas/parasitología , Incidencia
16.
Parazitologiia ; 26(6): 506-15, 1992.
Artículo en Ruso | MEDLINE | ID: mdl-1299805

RESUMEN

Simultaneous but separate feeding of ticks on nonviremic animal (guinea pig) has shown that Amblyomminae ticks are practically unable to transmit distantly tick-borne encephalitis virus (TBEV) to the specimens of their own subfamily and to Ixodinae as well. Ixodes persulcatus and I. ricinus displayed their ability as donors and recipients of TBEV (adults and nymphs) not only for their own subfamily representatives but also as donors for recipients of Amblyomminae subfamily (nymphs and adults of Dermacentor and Rhipicephalus and nymphs of Haemaphysalis). Experimental and literature data analysis permits the authors to conclude that the very important role of TBEV circulation in nature belongs to the distant virus transmission. The absence of such type of virus exchange among Amblyomminae excludes this group of ticks from active virus circulation in TBEV foci.


Asunto(s)
Vectores Arácnidos/microbiología , Virus de la Encefalitis Transmitidos por Garrapatas/patogenicidad , Encefalitis Transmitida por Garrapatas/transmisión , Garrapatas/microbiología , Animales , Vectores Arácnidos/clasificación , Dermacentor/microbiología , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/parasitología , Cobayas , Interacciones Huésped-Parásitos , Ninfa/microbiología , Garrapatas/clasificación
17.
Parazitologiia ; 17(5): 337-46, 1983.
Artículo en Ruso | MEDLINE | ID: mdl-6359021

RESUMEN

The paper presents a review of suggested and used methods of predicting the number of the main vector and its infection with the tick-borne encephalitis virus. It has been suggested that most practically important are long-term prognoses of tendencies in the changes of the parasitic system on the basis of retrospective estimation of the recurrence of its changes, that is, the definition of probability of recurrence of most important characters (states) of a parasitic system in the presence of appropriate external conditions.


Asunto(s)
Encefalitis Transmitida por Garrapatas/parasitología , Animales , Vectores Arácnidos/microbiología , Reservorios de Enfermedades , Ecología , Virus de la Encefalitis Transmitidos por Garrapatas , Encefalitis Transmitida por Garrapatas/transmisión , Femenino , Humanos , Masculino , Métodos , Dinámica Poblacional , Pronóstico , Garrapatas/microbiología , Factores de Tiempo
18.
Med Parazitol (Mosk) ; (4): 28-32, 1997.
Artículo en Ruso | MEDLINE | ID: mdl-9445992

RESUMEN

The serological survey of white hares (n = 8), squirrels (n = 118), and Asian chipmunks (n = 486) in the dark coniferous forests of Middle Siberia revealed tick-borne encephalitis virus antihemagglutinins only in the former two species (37.5 +/- 17.1 and 7.6 +/- 2.4%, respectively) and in the squirrel, there is a close seasonal relation between the parameters of immune interbred and those virophoricity of taiga tick nymphs.


Asunto(s)
Infecciones por Arbovirus/veterinaria , Reservorios de Enfermedades/veterinaria , Mamíferos/inmunología , Animales , Anticuerpos Antivirales/sangre , Infecciones por Arbovirus/inmunología , Infecciones por Arbovirus/parasitología , Arbovirus/inmunología , Reservorios de Enfermedades/estadística & datos numéricos , Virus de la Encefalitis Transmitidos por Garrapatas/inmunología , Encefalitis Transmitida por Garrapatas/inmunología , Encefalitis Transmitida por Garrapatas/parasitología , Encefalitis Transmitida por Garrapatas/veterinaria , Femenino , Ixodes/virología , Lagomorpha/inmunología , Lagomorpha/parasitología , Masculino , Mamíferos/parasitología , Sciuridae/inmunología , Sciuridae/parasitología , Estaciones del Año , Siberia
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