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1.
A literature review on the current situation of echinococcosis in Central Europe is given. The only final host for Echinococcus granulosus in this region ist the dog. The infection rate of dogs with E. granulosus in Central Europe is less than 1%. According to meat inspection statistics in Germany less than 0.008% of sheep, pigs and horses carry larval stages of E. granulosus. Parasitologically confirmed is the occurrence of a cattle-dog strain, the cysts of which were found in 0.26% of slaughter cattle. It is not known whether this strain infects also man as does the sheep-dog strain. Cases of cystic echinococcosis (E. granulosus) diagnosed in Central Europe are often imported from mediterranean countries. In Baden-Wurtemberg, the only state where human cases of echinococcosis are recorded, 50-100 cases are diagnosed per year. In areas with endemic E. multilocularis infection also dogs and cats may be infected with the adult worm besides the red fox. Recent investigations have revealed that not only in classical endemic areas (Switzerland, Austria, Baden-Wurtemberg, Rhineland-Palatinate) foxes have infection rates of up to 67% but that E. multilocularis-infection is also wide-spread in Thuringia, Hesse, Northrhine-Westphalia and in the southern parts of Lower Saxony. The most northern infested area seems to be the region of Detmold (infection rate of foxes 9%). The infection rates with alveolar echinococcosis (E. multilocularis) in humans even in endemic areas are low. In Baden-Wurtemberg 140 new cases became known during the past ten years.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

2.
In this paper, choropleth maps display the geographical distribution of Echinococcus multilocularis in red foxes in Lower Saxony. Areas of high prevalence of the infection in foxes and with high fox population density pose high risk for the human population for alveolar echinococcosis. Spatial statistical methods were used to analyse regional count data obtained from 5365 hunted or found-dead foxes. Spatial smoothing (of raw estimates of regional prevalences based on count data before mapping) was used because raw estimates can give an erratic impression of the spatial pattern of the infection. For smoothing, empirical Bayesian methods are used as an explorative spatial epidemiological tool. The resulting map showed the geographical variation of the estimated prevalences around a median at 9% and indicated the presence of spatial-trend effects. Based on this finding, conditional autoregressive spatial modelling for Freeman-Tukey transformed data was used as an inferential spatial epidemiological tool. There were significant additive linear and quadratic spatial-trend effects with elevated prevalences in the north and south and extreme values (prevalences>38%) for the south of Lower Saxony.  相似文献   

3.
The southern border of the European endemic area of Echinococcus multilocularis runs along the alpine crest. This endemic transition area was analysed in the canton Grisons on a small spatial scale. A total of 543 foxes originating from 10 areas north and 4 areas south of the main alpine divide were investigated. Parasites were isolated using the sedimentation and counting technique on intestinal contents. The mean prevalence of E. multilocularis was 6.4% with significant differences between different areas. In the southern valleys, only foxes from the Val Müstair were infected (14.3%). On the northern side of the main alpine divide, prevalences varied between 0 and 40%. The predation habits of foxes on potential intermediate hosts was investigated by means of stomach content analyses (n=530). Rodents of the genera Microtus/Pitymys were found in 19.6% of fox stomachs, Clethrionomys glareolus in 8.0% and Arvicola terrestris in 0.4%. A small scale analysis based on a 10 x 10 km grid suggested that the predation rate on the genera Microtus/Pitymys significantly correlated with the prevalence of E. multilocularis in foxes (Spearman's r = 0.51). Hence, E. multilocularis appears to occur in the alpine study area on a very small spatial scale. These local sources of infection may persist for decades. This may partly explains why, during the last 34 years, some human cases of alveolar echinococcosis occurred in areas of the Canton Grisons where the parasite is presently endemic in foxes. No such human cases have been recorded in other areas free of E. multilocularis.  相似文献   

4.
Echinococcus multilocularis parasitizes the small intestine of red foxes (Vulpes vulpes) and other carnivores, and has a wide distribution throughout the northern hemisphere. This cestode is the causative agent of human alveolar echinococcosis, a life-threatening helminth zoonosis. In 2000-2002, 2130 red foxes were examined for its presence in Slovakia, with a total prevalence of 30.7%. The data on occurrence were obtained by the combination of necropsy of small intestines from red foxes and coproantigen detection in faecal samples. The correlation between the number of detected specimens and the value of optical density of copro-ELISA test was found. When worm burdens were low (1-25 specimens) the sensitivity of the method was 31.3+/-8.64%, when worm burdens were >50 specimens, 81.8+/-0.66%, and with high worm burdens (>1000 specimens) the sensitivity reached 100+/-0.34%. E. multilocularis presence was detected using the nested PCR method from the eggs in the faecal samples with a 100% specificity. In epidemiological surveys of this zoonosis, it is of crucial importance to detect animals with a high level of infection, which are responsible for the bulk of environmental contamination. The advantage of copro-ELISA test lies in allowing the intravital diagnostics to be employed within the epidemiological survey of E. multilocularis occurrence in the protected and urban areas.  相似文献   

5.
Echinococcus multilocularis is a tapeworm having carnivores as final hosts, the red fox in particular, dog and cat less frequent. Its two host life cycle consists of a larval cycle which predominantly takes place in the liver of rodents such as mice but it can also develop in musk rats as intermediate hosts. Man can also be infected and serves as a wrong intermediate host. He develops an alveolar echinococcosis which usually ends lethal without medical treatment. The prevalence of E. multilocularis among 5.365 red foxes in Lower Saxony was monitored from 1991 to 1997. The data were analysed using spatial epidemiological methods. This evaluation is based on a significance test which was applied to the parameters of spatial autoregressive regression models (CAR) fitting to the data of two successive sampling periods from 1991-1994 and 1994-1997. The mean prevalence (spatial median) increased from 6% to 11%. The results of this epidemiological study which was restricted to Lower Saxony support for the first time the earlier reported assumption that the prevalence of foxes infected with E. multilocularis has risen in Europe in the last decade. The reasons for this development are still unknown.  相似文献   

6.
There is considerable interest in the spatial distribution of Echinococcus multilocularis in red foxes (Vulpes vulpes L.), because this parasite causes the zoonoses of alveolar echinococcosis which is potentially of high fatality rate. High risk areas are known from France, Switzerland and the Swabian Alb in Germany for a long time. In this work, the spatial scan statistic is introduced as an instrument for identification and localisation of high risk areas, so called disease clusters in spatial epidemiology. The use of the spatial scan statistic along with data about the distribution of the parasite in 5365 red foxes in Lower Saxony, that were collected during 1991 to 1997, led to the identification of another high risk area. The relative risk for this disease cluster is approximated by RR = 5.03 (CI0.95(RR) = [4.27; 6.58]) for the period of 1991 to 1994 and by RR = 4.45 (CI0.95(RR) = [3.53; 5.59]) for the period of 1994 to 1997, respectively.  相似文献   

7.
The so-called "fox tapeworm" (Echinococcus multilocularis), the causative agent of a severe disease in man (alveolar echinococcosis), is presently under public discussion in Switzerland. Therefore, actual information is provided on the life cycle of the parasite, epidemiology, disease in humans, symptomatology, diagnosis, therapy and prophylaxis. It is recommended that in endemic regions hunters handling foxes should wear protective gloves, dead foxes should be transported in plastic bags and wild fruits, berries and vegetables should be carefully washed and--if possible--heated to more than 70 degrees C for some minutes prior to consumption. After contact with foxes or other final hosts (dogs, cats) infected with E. multilocularis, persons should be monitored with the highly sensitive and specific Em2-ELISA for serum antibodies aiming at an early diagnosis and treatment of a potential infection.  相似文献   

8.
Ingestion of eggs of the small fox tapeworm, Echinococcus multilocularis, causes the severe human disease alveolar echinococcosis. Previously, the dynamics of the egg excretion from infected carnivores have been studied only where the host animals have been exposed to a single experimental infection. In nature, foxes are most likely repeatedly infected. To study the effect of repeated exposure, twenty-one foxes were inoculated with a high dose of E. multilocularis protoscoleces three times over a 1-month period. For comparative purposes, three groups of twenty-one foxes were respectively inoculated with low, medium, or high single dose of protoscoleces. For each group, worm number and morphology were analyzed after necropsy of seven foxes at 1, 2, and 4 months after last inoculation. The establishment of intestinal worms was very low in all foxes, and surprisingly, most of the worms did not produce eggs. Although most reproductive structures were detectable, the genital pore and the cirrus pouch often had abnormal enlargements that spread internally, most likely preventing the reproductive function. The reason for this abnormality could not be determined, but the preparation and storage conditions of the inoculated protoscoleces may have contributed to the stunted development. Physical stress of E. multilocularis at the larval stage in rodents may later adversely affect the reproductive success of the adult tapeworm in the carnivore definitive host; as in the present study where a worm establishment in the definitive host was only followed by a neglectable egg production.  相似文献   

9.
Two field trials to reduce the prevalence of Echinococcus multilocularis in foxes have been conducted in recent years. Although both trials reduced prevalence considerably, they failed to eradicate the parasite in the study region. Following the control trial in northern Germany, prevalence recovered unexpectedly and rapidly, reaching pre-control levels five quarters (15 months) after the end of control. To understand the internal dynamics of the parasite-host system's reaction to control, we developed a spatially explicit simulation model, Echi. The simulation model incorporates the information available concerning fox tapeworm population dynamics.Using epidemiological parameters to adjust pre-control prevalence, the model predicts the temporal evolution of the prevalence of E. multilocularis in controlled foxes without departing from the range of uncertainty of the field data. However, the model does not predict the rapid pre-control recovery observed in the field trial.The deviation of the model's prediction from field data indicates the involvement of processes not yet taken into account. We modified the model step by step to mimic processes with the potential to cause the rapid post-control recovery of the prevalence of E. multilocularis in foxes.Neither the longevity of tapeworm eggs nor the migratory behaviour of foxes showed any influence on the post-control reaction of the parasite-host system. However, landscape structures leading to a heterogeneous distribution of infected foxes have the potential to alter the system's reaction to control. If infected foxes are concentrated in multiple clusters in the landscape, the model prediction tallied with the range of uncertainty of the field data. Such spatial distribution of infected foxes may be caused by differential abiotic conditions influencing the survival of tapeworm eggs.The model was found to comply best with field data if the foxes acquire partial immunity by being exposed to the fox tapeworm.Both hypotheses explaining the rapid post-control recovery of the prevalence of E. multilocularis observed in the fox population were supported by field data.Both hypotheses have far-reaching consequences for future control trials. The spatial aggregation of infected foxes would enable control efforts to be concentrated on these highly infected areas. However, the acquisition of immunity acts as a buffer to control, necessitating intensified control measures.  相似文献   

10.
The prevalence rates of Echinococcus multilocularis in foxes (n=5600) evaluated in several Austrian surveys conducted between 1991 and 2004 were analysed for spatial and temporal differences. Data from early studies (1993-1997) in which the intestinal scraping technique (IST) was utilized were compared with data from recent (1999-2004) investigations, which made use of the shaking in a vessel technique (SVT), and it was assessed whether or not the infection rates of Austrian foxes had increased between the investigated intervals. In total, data from 85 districts are presented and both the retrospective and recent data are available from 39 of these districts. A Bayesian hierarchical model of parasite prevalences is presented which (i) accounts for differences in the sensitivity of IST and SVT, (ii) incorporates spatial auto-correlation between neighbouring districts, (iii) investigates the possibility of a temporal shift in the infection status of foxes, and (iv) quantifies uncertainty at each level of the model. The national average prevalence rates in the mid-1990s and at the turn of the millennium were 2.4% (95% confidence intervals 1.1-4.8) and 3.9% (95% confidence intervals 1.5-8.4) respectively. Above average prevalence rates were observed in the western and the northern parts of the country. Evidence is also presented for a temporal augmentation of the prevalence rates in some districts in the northern and eastern parts of the country. These findings are in concordance with several investigations in other European states where both newly emerged areas and elevated levels of transmission in existing endemic areas have been found. None of the districts investigated here showed significant evidence of a drop in prevalence.  相似文献   

11.
The base line prevalence of Echinococcus multilocularis in foxes was determined in the eastern part of the province of Groningen in the Netherlands adjacent to the German border. This region has been identified in a previous study in 1998 as one of the westernmost border areas of E. multilocularis. Base line prevalence data are important for a better insight in the possible spread of the parasite and its changes in time. As fox feces containing E. multilocularis eggs are an important source for human exposure this base line prevalence is also an indicator for the potential risk for public health. The base line prevalence was estimated at 9.4% (95% CI: 5.2-16.5%). These results confirm previous findings of E. multilocularis in the same region. The spatial distribution of the infected foxes has been analyzed as a spatial gradient using a logistic model. The prevalence appeared to change strongest in east-western direction and was highest near the German border, adjacent to a German endemic area. These results suggest that the border areas in the Netherlands are the most margin of E. multilocularis territory.  相似文献   

12.
Recently, a wealth of new data was collected on the distribution and ecology of E. multilocularis. The parasite is now known to occur at surpisingly high prevalence rates in e.g. Belgium and northwestern Germany, new records exist for the Netherlands, and the parasite was found to be widespread in Poland and the Czech Republic. In addition, foxes in continental Europe have adapted their behaviour and are now common in many towns and cities where they are also known to carry the parasite. New data exist on endemicity regions in western Asia. In addition to new informations on the parasite's range, a summary is given of the current knowledge on prevalence of alveolar echinococcosis in man.  相似文献   

13.
The parasite Echinococcus multilocularis is currently of great concern in Europe because of its spreading behavior, which has public health implications. This study investigates the spatiotemporal distribution of Echinococcus multilocularis in Red Foxes. The infection status of 8459 foxes was sampled from 43 regions in the north German province of Lower Saxony over three investigation periods 1991--1994, 1994--1997 and 2003--2005. Linear empirical Bayesian smoothing within the binomial model was used to produce smoothed choropleth maps. Geostatistical kriging was applied to generate prevalence risk maps. Further geostatistical modeling of the prevalence difference between study periods facilitated spatiotemporal trend investigations. The spatial scan statistic was used for cluster detection analysis. The average prevalence risk for Lower Saxony increased from about 12 to 20% during 1991--2005. Specifically the increases from first to second and to third study periods were estimated by 3.3% (CI 95%: 0.6%-5.9%) and 8.5% (CI 95%: 5.2%-11.8%), respectively. Infections in foxes were clustering and a location stable disease cluster was detected in the south of the province. This study is the first showing evidence for steady emergence of Echinococcus multilocularis in Red Foxes. First cases of human Alveolar Echinococcosis were recorded recently.  相似文献   

14.
Human alveolar echinococcosis, caused by the tapeworm Echinococcus multilocularis, is the most pathogenic helminthic zoonosis in the temperate and arctic region of Europe. Between November 2008 and February 2009, 840 red fox (Vulpes vulpes) carcasses, were randomly collected from the whole Hungarian territory. The intestinal mucosa from all the foxes was tested by sedimentation and counting technique. E. multilocularis adult worms were detected in foxes of 16 out of the 19 Hungarian counties and in the suburban areas of the capital, Budapest. The prevalence and abundance of infection was significantly (P<0.001) higher in the north-western half (16.2%, CI=14.5-17.9; m ± SE=165.5 ± 112.4) than in the south-eastern half of the country (4.2%, CI=3.2-5.2; m ± SE=3.6 ± 2.1). The highest prevalence (26.6%, CI=22.5-30.8%) and abundance (m ± SE=614.2 ± 469.3) was observed in the Northern Mountain Region bordering Slovakia. The multi-locus microsatellite analysis of 81 worms showed the presence of four out of the five main European profiles. The H profile was the most common profile (55.5%) with nine genotypes, followed by the G (18.5%) with two genotypes, E (13.6%) with one genotype and D (12.4%) with two genotypes. The genetic distance was not statistically correlated with the geographical distance of the samples, supporting the hypothesis that the geographical distance is only a minor factor among those involved in the genetic distribution of this parasite in Europe. These data indicate that Hungary should be considered as a peripheral area of a single European focus, where the dispersal movement of foxes resulted in the spreading of the parasite from one county to another within a time period short enough to avoid a substantial genetic drift.  相似文献   

15.
Human alveolar echinococcosis is a life-threatening parasitic zoonosis which occurs in rare cases in Central Europe. It is caused by the larval stage of Echinococcus multilocularis. In this publication, strategies for the control of parasites of the genus Echinococcus are reviewed and discussed with regard to their applicability to E. multilocularis on the background of the epidemiological situation in Central Europe. First results of field studies are presented in which strategies based on the application of praziquantel-containing baits to foxes have been tried. Requirements concerning the surveillance of control measures are demonstrated and the limitations of the imaginable control strategies discussed.  相似文献   

16.
Human alveolar echinococcosis (AE), caused by the metacestode stage of Echinococcus multilocularis, is a serious zoonosis which caused up to 100% lethality in untreated patients before the 1970s, when modern methods of treatment were not yet established. AE occurs in large areas of the northern hemisphere mostly with low country-wide prevalences, but high prevalences of up to 4% have been reported from small population groups in highly endemic foci, e.g. from China. AE includes many veterinary aspects which are the topic of this review. Recent studies have shown that E. multilocularis has a wider geographic range than previously anticipated. There is evidence for growing populations of red foxes (Vulpes vulpes) in some areas, for increasing invasion of cities by foxes and also for establishment of the parasite cycle in urban areas. These and other factors may lead to an increased infection risk for humans. Significant progress has been made in the development of sensitive and specific new techniques for the intra vitam and post mortem diagnosis of intestinal E. multilocularis infection in definitive hosts, notably the detection of coproantigen by enzyme-linked immunosorbent assay and of copro-DNA by PCR. Both tests can also be used for the identification of E. multilocularis in faecal samples collected in the environment. Recommendations are given for chemotherapy and chemoprophylaxis of the intestinal infection in definitive hosts. In recent years, infections with the metacestode stage of E. multilocularis have not only been diagnosed in humans in several regions, including at least eight countries in central Europe, but also in animal species which do not play a role in the transmission cycle (wild and domestic pigs, dogs etc.). From 1987 to 2000 our group in Zurich has diagnosed 10 cases of AE in dogs and 15 in captive monkeys. In 2 dogs, concurrent infections of the intestine and of the liver with adult and larval stages of E. multilocularis, respectively, were observed for the first time. Clinical data are presented, and methods of diagnosis and treatment (surgery, chemotherapy) are described. Furthermore, small liver lesions caused by E. multilocularis were diagnosed in 10% of 90 slaughter pigs, and 2.9% of 522 breeding sows had specific serum antibodies against parasite antigens. In view of the unpredictable epidemiological situation, all possible measures for preventing E. multilocularis infections in humans and in domestic animals should be initiated by the veterinary and health authorities.  相似文献   

17.
Between November 1989 and June 1990 a total number of 397 foxes were examined for the presence of cestodes. The animals came from the districts of Arnsberg, Detmold and Kassel. In 16.4% of the foxes infections with Echinococcus multilocularis were found, in 28.5% Taenia crassiceps, in 14.4% Taenia polyacantha, in 4.3% Mesocestoides spp., in 3.3% Multiceps multiceps, in 2.5% Hydatigera taeniaeformis, in 0.8% Taenia hydatigena and in 0.3% Taenia martis. Infections with Echinococcus multilocularis very often showed high worm numbers of more than 1000 per fox. The number of worms for the other cestodes mostly varied between one and ten specimen per animal.  相似文献   

18.
Anthelmintic (praziquantel) baiting of wild red foxes against Echinococcus multilocularis infection was studied in a highly epizootic suburban area of Otaru, Hokkaido (the northern island of Japan) during the summer and autumn in the years 1999-2004. Acceptance of baits containing the biomarker tetracycline (TC) was evaluated. The prevalence of E. multilocularis infection in foxes before baiting (1999-2000) was 58% (88/153), whereas in the fourth year of bait distribution year (2004), it decreased to 11% (5/45). Analysis of TC marking in the teeth of foxes showed that 39% (77/195) of those captured after baiting were estimated to have consumed baits in the year of capture. Importantly, more juvenile (56%, 49/87) than adult foxes (26%, 28/108) were marked, indicating efficient baiting of juveniles, which tended to have a higher worm burden of E. multilocularis. Of 77 marked foxes, E. multilocularis and Alaria alata (monitored as the second indicator species of deworming) were not detected in 70 (90%) and 76 (99%) foxes, respectively. The results suggest effective deworming by bait consumption. However, it was also demonstrated that 9% of the marked foxes were infected or re-infected after bait consumption, suggesting high infection pressure and the importance of frequent baiting.  相似文献   

19.
Alveolar echinococcosis, caused by the metacestode Echinococcus multilocularis, is a zoonosis of public health significance. Apart from red foxes, other carnivore species can also serve as definitive hosts of this parasite. This study aimed to determine the occurrence of E. multilocularis in dogs in the Slovak Republic and identify risk factors for acquiring the infection. Out of 289 dogs examined, E. multilocularis was detected in eight samples (2.8%). Positive results were observed in shepherd dogs (12.5%), guard dogs (7.1%), hunting dogs (2.4%) and in one dog with unknown usage (2.5%). Catching rodents and feeding with raw viscera were confirmed to be the most important risk factors for E. multilocularis infection. On the contrary, the way of dog use, frequency of going to the rural areas, the age and gender of animals seem not to be risk factors for infection. No significant association was observed between the positivity of dogs coming from high endemic or non-endemic regions. This is the first report of E. multilocularis in dogs in the Slovak Republic that confirms substantial contribution of dogs to the transmission of the tapeworm in this territory and urges the necessity of prophylactic measures for dog owners.  相似文献   

20.
The Tibetan plateau of western China has been shown to have a very high prevalence of human cystic echinococcosis (CE) caused by Echinococcus granulosus and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. A purgation study of 371 dogs in Shiqu County, Sichuan Province during 2002-2003 resulted in an E. multilocularis prevalence of 12% and an E. granulosus prevalence of 8%. These crude prevalences were then adjusted, based on the known sensitivity of arecoline purgation for the detection of E. granulosus and a suggested sensitivity for the detection of E. multilocularis. In addition, it was assumed that some immature parasites of either species could be misidentified morphologically and wrongly assigned. This resulted in credible true prevalence intervals of between 13-33% for E. multilocularis and 8-19% for E. granulosus. Prevalences of other intestinal helminthes found on purgation were: Taenia spp. 31%, Dipylidium caninum 1%, and ascarids 8%. Risk factors associated with the acquisition of canine echinococcosis were evaluated based on responses to a questionnaire administered to dog owners. Male dogs were more likely to be infected with Echinococcus spp. than female dogs (P<0.05) and dogs allowed to roam were more likely to be infected with E. multilocularis (P<0.05).  相似文献   

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