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1.
Twenty ferrets (Mustela putorius furo) were inoculated by intramuscular (i.m.) injection with European Bat Lyssaviruses (EBLV) type-1 and 2 using 10(4.0) foci-forming units (FFU) EBLV-2 (n = 6), 10(4.0) FFU EBLV-1 (n = 7) and 10(6.0) FFU EBLV-1 (n = 7). Furthermore, 15 mice received 10(2.5) FFU EBLV-2 (n = 5), 10(2.5) FFU EBLV-1 (n = 5) and 10(4.5) FFU EBLV-1 (n = 5) by i.m. inoculation. All ferrets and mice receiving the higher dose of EBLV-1 succumbed to infection. In contrast, only three of seven ferrets and two of five mice inoculated experimentally with the lower EBLV-1 dose died. By comparison, all of the EBLV-2 infected ferrets and four of five mice survived infection. All 20 infected ferrets seroconverted. Using sensitive molecular tools, the virus was detected in different tissues, but it could not be found in any saliva samples taken during the 84-day observation period.  相似文献   

2.
A comparative study of immunogenicity and efficacy of the oral rabies virus vaccine SAD P5/88 in raccoon dogs and foxes was conducted. The raccoon dogs received 10(6.9) (n = 6), 10(6.3) (n = 6) or 10(5.7) FFU SAD P5/88 (n = 5) by direct oral application, and subsequently all animals seroconverted. The foxes received 10(7.2) (n = 4), 10(6.2) (n = 4), 10(5.2) (n = 4) and 10(4.2) FFU SAD P5/88 (n = 5) by the same route. On days 106 and 196 post vaccination 10 raccoon dogs and 16 foxes were challenged with a relevant street virus, respectively. All 10 raccoon dogs vaccinated with 10(6.3) (n = 5) or 10(5.7) FFU SAD P5/88 (n = 5) survived the challenge, whereas all control animals (n = 5) died of rabies. Two foxes vaccinated with 10(4.2) FFU and one fox vaccinated with 10(5.2) FFU died of rabies on day 7, 17 and 12 post infection, respectively. Also all control foxes succumbed to rabies. Our findings demonstrate that SAD P5/88 is not only an effective vaccine for oral vaccination of foxes but also for that of raccoon dogs.  相似文献   

3.
European bat lyssavirus type 1 (EBLV-1, genotype 5) is known to endemically circulate in insectivorous bat populations in Germany. In August 2001, a rabies suspect stone marten (Martes foina) was found in the city of Burg (Saxony-Anhalt, Germany) and was sent to the regional veterinary laboratory for routine rabies diagnosis. Whereas brain samples repeatedly tested negative in the fluorescent antibody test for classical rabies virus (genotype 1), the mouse inoculation test and the rabies tissue culture inoculation test yielded positive results. Rabies viral RNA was also detected in the stone marten brain sample both by nested and heminested RT-PCR specific for the nucleoprotein gene and for the nucleoprotein phosphoprotein junction of rabies virus. The amplification products were sequenced to genotype the isolate. Sequence data obtained from the first-round RT-PCR products were analysed and the suspect stone marten isolate was confirmed as a rabies related virus (EBLV-1a). Phylogenetic comparison with sequences from recent genotype five isolates from Germany and Denmark showed that it was closely related to a previous isolate of EBLV-1 from a serotine bat in Saxony-Anhalt obtained in the same year in an area adjacent to the place where the EBLV-1 infected stone marten was found. Both EBLV-1 isolates share a 99.5% identity. This is the first report of an EBLV-1a spill-over from an insectivorous bat into wildlife in Europe.  相似文献   

4.
Studies on the immunogenicity and efficacy of SAD B19 attenuated rabies virus vaccine in foxes under laboratory conditions were conducted. Twenty-seven foxes (Vulpes vulpes) were offered a vaccine bait containing 10(6.3) FFU/ml SAD B19. Blood samples were collected 60, 110 and 190 days post-vaccination. On day 190 post vaccination the animals and 14 controls were challenged with a canid street rabies virus. Twenty-four of the 26 vaccinated foxes (92.3%) survived the challenge, whereas all the controls died from rabies. The two vaccinated foxes that did not survive the challenge did not show any detectable level of rabies neutralizing antibodies at any time after vaccination. The geometric mean titres (GMT) of foxes that seroconverted after vaccination were 43.5, 33.9 and 43.5 IU/ml 60, 110 and 190 days post-vaccination, respectively. Furthermore, to test the vaccine virus under sub-optimal conditions five naive and nine previously vaccinated vixens received 2 ml SAD B19 (10(6.7) FFU/ml) by direct administration of the vaccine virus into the oral cavity shortly before or during pregnancy. All vixens seroconverted above the threshold of 0.5 IU/ml. No booster effect was observed in the immune response of the previously vaccinated animals.  相似文献   

5.
In Europe, rabies in bats is caused by European Bat Lyssavirus (EBLV) type 1 (EBLV-1) or type 2 (EBLV-2) which form two distinct genotypes (gt 5 and 6) within the genus Lyssavirus of the family of Rhadoviridae. Spill-over infections of EBLV in humans have caused fatal rabies encephalitis and highlighted the relevance of this wildlife disease for public health. The vast majority of the 831 European bat rabies cases reported between 1977 and 2006 were identified as EBLV-1. Only few virus isolates originating from Switzerland, The Netherlands and the United Kingdom were characterized as EBLV-2. Here we report the first EBLV-2 case detected in Germany in a Daubenton's bat (Myotis daubentonii) in August 2007. The bat showed clinical signs of disorders of the central nervous system and subsequently tested positive for rabies. The virus was isolated and characterized as EBLV-2 based on its antigen pattern and by nucleotide sequencing. Phylogenetic analysis indicated an association to EBLV-2 isolates from Switzerland which correlates with the origin of the bat close to the Swiss border.  相似文献   

6.
The efficacy of a vaccinia-rabies recombinant virus (10(8) TCID50) contained in a machine-made baiting system has been tested in 22 captive young foxes which were divided into three experimental groups of six and a control group of four foxes. Each fox in groups 1, 2 and 3 were fed one, two and three vaccine-baits, respectively, on successive days. The four unvaccinated foxes were housed separately. As shown by the incorporation of a tetracycline biomarker into their bones, all the baited foxes ingested at least one bait. Thirty days after baiting seroconversion to rabies was observed in 15 (83 per cent) of the foxes and seroconversion to vaccinia in 14 (78 per cent). Sixteen of the 18 (89 per cent) baited foxes resisted a rabies challenge 30 days after baiting. One cub was protected against rabies despite the absence of detectable anti-rabies antibody. The results demonstrate that the bait-sachet system permits a good release of the virus suspension into the mouth.  相似文献   

7.
A field trial in Belgium to control fox rabies by oral immunisation   总被引：1，自引：0，他引：1  
Campaigns of fox vaccination against rabies were carried out in Belgium in September 1986 and June and September 1987. The SAD B19 attenuated strain of rabies virus was inserted into baits which were distributed over an area of 2100 km2 at a density of 11 baits/km2. As recommended by the World Health Organisation, the efficacy and the innocuity of the method were controlled in the field and in the laboratory. Samples of blood and brain and jaw were taken from foxes which were shot or found dead in the vaccination area, for the diagnosis of rabies, the titration of antirabies antibody and the detection of tetracycline marker. In rabid animals, the virus strain was characterised by immunofluorescence using monoclonal antibodies. In September 1987, the uptake of the baits had reached 72 per cent by 14 days after distribution. Several wild species competed with foxes in taking the baits. After the last campaign, tetracycline was found in 65 per cent of the healthy foxes collected and rabies virus neutralising antibodies were detected in 77 per cent of them. In 1987, the incidence of rabies decreased markedly in the vaccination area compared with the untreated areas. No vaccine virus was isolated either from rabid animals or from 228 small mammals trapped in the vaccination area.  相似文献   

8.
Foxes given ERA rabies vaccine baits were challenged at one, six, 12 and 24 months later and showed a resistance to challenge in 80%, 78%, 60% and 44% of individuals respectively. All animals showing seroconversion following vaccination, resisted challenge at 24 months, suggesting that successful vaccination by the oral route could confer a relatively long term duration of immunity. The trials showed that fox pups did not immunize as easily as adult foxes using ERA rabies vaccine baits. Back-passage studies and the consumption of ERA injected mice by foxes failed to show any reversion of the vaccine virus to a virulent state. The fox and mouse are shown to be highly susceptible to rabies street virus, while the domestic species tested are consisderably more resistant. Monkeys were found to be intermediate in susceptibility to the virus. Safety tests carried out on various species of wildlife showed only the mouse to be susceptible to infection from ingesting the vaccine in the form of a bait. ERA rabies vaccine was shown to be safe in monkeys even when high titred virus was administered by the oral route.  相似文献   

9.
OBJECTIVE: To examine the susceptibility of the grey-headed flying fox (Pteropus poliocephalus) to Australian bat lyssavirus (ABL), and to provide preliminary observations on the pathogenesis of the disease in flying foxes. PROCEDURE: Ten flying foxes were inoculated intramuscularly with ABL, and four with a bat-associated rabies virus. Inoculated animals were observed daily, and clinical samples collected every 9 to 14 days. Animals with abnormal clinical signs were euthanased, and samples collected for histological, serological, virological and immunohistological examinations. At 3 months post inoculation (PI), all survivors were euthanased, and each submitted to a similar examination. RESULTS: Three ABL-inoculated flying foxes, and two rabies-inoculated animals developed abnormal clinical signs between 15 and 24 days PI. All three ABL-inoculated animals had histological lesions consistent with a lyssavirus infection, and lyssaviral antigen was identified in the central nervous system (CNS) of each. Virus was isolated from the brain of two affected animals. Of the rabies-inoculated flying foxes, both had histological lesions and viral antigen in the CNS. Virus was recovered from the brain of only one. None of the five affected flying foxes developed anti-lyssavirus antibodies, but, by 3 months PI, five of the seven ABL-inoculated survivors, and one of the two rabies virus-inoculated survivors, had seroconverted. The dynamics of the immune responses were quite variable. CONCLUSIONS: The response of flying foxes to ABL, administered by a peripheral route of inoculation, was similar to that of bats inoculated peripherally with bat-derived rabies viruses.  相似文献   

10.
Thirteen fox cubs were orally administered 10(7.2) plaque-forming units of live vaccinia-rabies glycoprotein recombinant virus. On Day 28 post-vaccination, all but 1 cub had produced rabies virus antibodies. Twelve animals were intramuscularly inoculated with 10(3.2) mouse intracerebral LD50 of rabies virus suspension on Days 33 (5 foxes), 180 (4 foxes) or 360 (3 foxes) after vaccination. Eleven of them resisted rabies challenge. Unvaccinated foxes, either put in contact with 1 vaccinated animal or used as controls, died after challenge applied on Day 33. The absence of horizontal transmission of this vaccine strain and its innocuity to cubs were also demonstrated.  相似文献   

11.
The virulence of hantaviruses that are antigenically related but have different genetic characteristics from the prototype of hantavirus, Hantaan (HTN) virus, was examined in newborn mice. The H5 and B78 strains of the Amur (AMR) genotype, the Bao14 strain of the Far East (FE) genotype, and the 76-118 strain of HTN virus were inoculated subcutaneously (1focus-forming unit; FFU) into newborn mice. All of the AMR and FE genotype viruses inoculated mice were died by 16 days post-infection (dpi) and 21 dpi, respectively, while 50% of the HTN virus inoculated mice survived until 30 dpi. The AMR and FE genotype viruses inoculated mice had high viral titers in the lung (1.3x10(6) to 1.3x10(8) FFU/gram [g] tissue) , brain (2.1x10(7) to 1.2x10(9) FFU/g tissue), and kidney(2.5x10(5) to 1.6x10(7) FFU/g tissue), and showed a detectable level of antibodies (titers 1:16-1:32) at 14 dpi. In contrast, the HTN virus infected mice had viruses only in the lungs at low titers (1.1-5.3x10(5) FFU/g tissue). Observations of body-weight changes revealed that the AMR and FE genotype viruses inoculated mice had lower growth rates than the HTN virus inoculated mice. These data suggest that the AMR and FE genotype viruses are more virulent than the HTN virus in newborn mice.  相似文献   

12.
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13.
The incidence of canine rabies has been widely reported in Brazil, and new rabies virus (RV) variants, genetically similar to canine RV, have recently been isolated from foxes. In order to derive the epidemiological characteristics of Brazilian Carnivora RV, Brazilian RVs isolated from dogs, cats, and foxes were genetically analyzed. Brazilian Carnivora RV isolates were divided into 2 main lineages. The predominant lineage was found in dogs and cats, which included the Argentinean and Bolivian Carnivora RV isolates, and was extensively distributed throughout Brazil and surrounding countries. The other lineage consisted of three sublineages containing Brazilian dog and fox RV isolates, with the dog sublineages located on an internal branch of 2 fox sublineages, suggesting that RV transmission events might have occurred between foxes and dogs in the past. These results suggest that contact between dogs and wildlife has the potential to generate new rabies variants and that it is important to control RV infection cycles in both dogs and wildlife to prevent spread of rabies infection.  相似文献   

14.
Due to the oral vaccination of foxes against rabies most of the territory of Poland was freed from rabies of non-flying mammals. In January 2021, rabies was diagnosed in fox in the central part of Mazowieckie Voivodeship where rabies has not been detected since last 17 years. Subsequently, in the following months the rabies virus infection spread southward reaching the voivodeship of Świętokrzyskie in November 2021. Emergency actions were implemented aiming at rapid rabies elimination.  相似文献   

15.
European bat lyssaviruses (EBLVs) have been known to cross the species barrier from their native bat host to other terrestrial mammals. In this study, we have confirmed EBLV-1 and EBLV-2 susceptibility in sheep (Ovis ammon) following intracranial and peripheral (intramuscular) inoculation. Notably, mild clinical disease was observed in those exposed to virus via the intramuscular route. Following the intramuscular challenge, 75% of the animals infected with EBLV-1 and 100% of those that were challenged with EBLV-2 developed clinical signs of rabies and then recovered during the 94-day observation period. Disease pathogenesis also varied substantially between the two viruses. Infection with EBLV-1 resulted in peracute clinical signs, which are suggestive of motor neuron involvement. Antibody induction was observed and substantial inflammatrory infiltrate in the brain. In contrast, more antigen was detected in the EBLV-2-infected sheep brains but less inflammatory infiltrate and no virus neutralising antibody was evident. The latter involved a more protracted disease that was behaviour orientated. A high infectious dose was required to establish EBLV infection under experimental conditions (> or =5.0 logs/ml) but the infectious dose in field cases remains unknown. These data confirm that sheep are susceptible to infection with EBLV but that there is variability in pathogenesis including neuroinvasiveness that varies with the route of infection. This study suggests that inter-species animal-to-animal transmission of a bat variant of rabies virus to a terrestrial mammal host may be limited, and may not always result in fatal encephalitis.  相似文献   

16.
SUMMARY: During 2007, 49 states and Puerto Rico reported 7,258 cases of rabies in animals and 1 case in a human to the CDC, representing a 4.6% increase from the 6,940 cases in animals and 3 cases in humans reported in 2006. Approximately 93% of the cases were in wildlife, and 7% were in domestic animals. Relative contributions by the major animal groups were as follows: 2,659 raccoons (36.6%), 1,973 bats (27.2%), 1,478 skunks (20.4%), 489 foxes (6.7%), 274 cats (3.8%), 93 dogs (1.3%), and 57 cattle (0.8%). Compared with numbers of reported cases in 2006, cases in 2007 increased among dogs, bats, foxes, and skunks while decreases were reported among cattle, cats, and skunks. Increases in numbers of rabid raccoons during 2007 were reported by 11 of the 20 eastern states where raccoon rabies was enzootic, and reported cases increased by 1.7% overall, compared with 2006. On a national level, the number of rabies cases in skunks during 2007 decreased by 1.1% from the number reported in 2006. Texas reported the greatest number (n = 362) of rabid skunks and the greatest overall state total of animal rabies cases (969). No cases of rabies associated with the dog/coyote rabies virus variant were reported. The United States remains free of dog-to-dog transmission of canine rabies virus variants. The total number of cases of rabies reported nationally in foxes increased 14.5%, compared with 2006. Increases in the number of reported rabid foxes were attributable to greater numbers of foxes reported with the Arctic fox rabies virus variant in Alaska, the Texas gray fox rabies virus variant in Texas, and the raccoon rabies virus variant in Virginia. The 1,973 cases of rabies reported in bats represented a 16.6% increase over numbers reported in 2006. Cases of rabies in dogs and in sheep and goats increased 17.7% and 18.2%, respectively, whereas cases reported in cattle, cats, and horses and mules decreased 30.5%, 13.8%, and 20.8%, respectively. In Puerto Rico, reported cases of rabies in mongooses decreased 51.5%, and rabies in domestic animals, presumably attributable to spillover infection from mongooses, increased 25%. One human rabies case was reported from Minnesota during 2007. Although typing of the rabies virus variant in this case was not possible, an investigation of this case indicated a bat as the most likely source of exposure.  相似文献   

17.
European bat lyssavirus type 1a (EBLV-1a) was first identified in central France from a serotine bat (Eptesicus serotinus) collected at the end of 2002. Rabies was diagnosed by reference rabies diagnosis methods and molecular tools. Phylogenetic analysis of 14 viral isolates obtained from French bats infected with EBLV-1 between 1989 and the end of 2002 against 47 nucleoprotein sequences showed a north-west to east distribution of EBLV-1a virus and a south to north distribution of EBLV-1b virus, isolates of which could be divided into two groups: group 1 in north-eastern France and group 2 in central and north-western France.  相似文献   

18.
When rabies reappeared in Finland in April 1988, the country had been rabies free since 1959. Soon a picture of sylvatic rabies become evident, its main vector and victim being the raccoon dog (Nyctereutes procyonoides). Between 8 April 1988 and 16 February 1989, 66 virologically verified cases were recorded (48 raccoon dogs, 12 red foxes, 2 badgers, 2 cats, 1 dog and 1 dairy bull) in an area estimated at 1700 km2 in south-eastern Finland. The greatest distance between recorded cases was 67 km. A positive reaction with monoclonal antibody p-41 indicated that the virus was an arctic-type strain. A field trial on oral immunization of small predators was initiated in September 1988 using Tübingen fox baits according to the Bavarian model of bait distribution. Each bait contained 5*10(7) TCID50/ml modified live rabies virus (SAD-B19). The 6 months' surveillance indicate a seroconversion rate of 72% (N = 126) in the raccoon dog population, 67% (N = 56) in the red foxes and 13% (N = 16) in the badgers, when titers greater than or equal to 1.0 IU/ml are considered seropositive. In the whole follow-up period, no statistically significant difference could be detected between the raccoon dogs and red foxes in the rate of seroconversion or in the uptake of tetracycline from the baits. Notably high antibody levels were recorded in both raccoon dogs and red foxes within 4-5 months after vaccination. Of the seropositive animals, the proportion of animals with titers 3.0 IU/ml or greater was higher in raccoon dogs (73%) than in red foxes (51%) (x2 = 5.29, p less than 0.05). The trial shows that raccoon dogs can be immunized against rabies in the field with vaccine baits originally developed for controlling sylvatic rabies in foxes.  相似文献   

19.
The direct and interactive effects of climate change on host species and infectious disease dynamics are likely to initially manifest\ at latitudinal extremes. As such, Alaska represents a region in the United States for introspection on climate change and disease. Rabies is enzootic among arctic foxes (Vulpes lagopus) throughout the northern polar region. In Alaska, arctic and red foxes (Vulpes vulpes) are reservoirs for rabies, with most domestic animal and wildlife cases reported from northern and western coastal Alaska. Based on passive surveillance, a pronounced seasonal trend in rabid foxes occurs in Alaska, with a peak in winter and spring. This study describes climatic factors that may be associated with reported cyclic rabies occurrence. Based upon probabilistic modelling, a stronger seasonal effect in reported fox rabies cases appears at higher latitudes in Alaska, and rabies in arctic foxes appear disproportionately affected by climatic factors in comparison with red foxes. As temperatures continue a warming trend, a decrease in reported rabid arctic foxes may be expected. The overall epidemiology of rabies in Alaska is likely to shift to increased viral transmission among red foxes as the primary reservoir in the region. Information on fox and lemming demographics, in addition to enhanced rabies surveillance among foxes at finer geographic scales, will be critical to develop more comprehensive models for rabies virus transmission in the region.  相似文献   

20.
Acute disseminated toxoplasmosis was diagnosed in three wild arctic foxes (Alopex lagopus) that were found dead in the same locality on Svalbard (Norway). The animals included one adult female and two 4-months-old pups. The adult fox was severely jaundiced. Necropsy revealed multifocal, acute, necrotizing hepatitis, acute interstitial pneumonia, and scattered foci of brain gliosis, often associated with Toxoplasma tachyzoites. One pup also had Toxoplasma-associated meningitis. In addition, the latter animal was infected with Yersinia pseudotuberculosis serotype 2b and Salmonella Enteritidis phage type 1 (PT1), which may have contributed to the severity of the Toxoplasma infection in this animal. The diagnosis of toxoplasmosis was confirmed by positive immunohistochemistry and detection of anti-Toxoplasma gondii antibodies in serum of all foxes. The animals were negative for Neospora caninum, canine distemper virus, canine adenovirus, and rabies virus on immunolabelling of tissue sections and smears.  相似文献   

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