[Show abstract][Hide abstract]ABSTRACT: SUMMARY The incidence of rabies in livestock is an important factor for estimating the economic impact of the disease, but obtaining reliable data is hindered by inadequate surveillance. In order to understand the contribution of livestock rabies to the overall burden of disease, the rabies incidence in cattle was investigated in detail for Turkey between 2008 and 2011. Data were compiled on cattle numbers, samples submitted for rabies diagnosis, vaccinated animals and positive rabies cases in animals for seven regions in Turkey. Rabies incidence in cattle fluctuated annually and differed between regions from 0·10 to 3·87 cases/100 000 animals. The positive influence of compensation schemes was observed. Livestock losses were conservatively estimated at around $250 000 international dollars per annum, although in areas where compensation schemes are not operating this could be an underestimate of the economic burden. Vaccination of cattle remains an option for disease prevention, although oral rabies vaccination through aerially distributed baits should be implemented to prevent the further spread of fox-mediated rabies, which could result in much greater economic costs.
Full-text · Article · Nov 2013 · Epidemiology and Infection
[Show abstract][Hide abstract]ABSTRACT: Rabies is one of the oldest diseases known to mankind and continues to pose a threat to human and animal health. Of relevance to this book, animals are always the source of infection in humans. There is no evidence for human-to-human transmission. Any changes in the biology or distribution of a rabies reservoir species, which reside primarily in the orders Chiroptera and Carnivora, not only lead to opportunities for human infection with rabies virus but also influence changes in virus evolution, spread and diversity. Fundamental changes in human sociocultural evolution and population growth, together with related activities, including the domestication of dogs in particular, have substantially contributed to the spread of rabies virus and influenced the present-day global distribution of the disease. This distribution is in constant flux as other factors such as the translocation of animals, urbanization, and climate change affect transmission rates or lead to additional spread of the disease. This chapter discusses the wide variety of animal vectors of rabies virus and the factors that lead to contact with human populations.
[Show abstract][Hide abstract]ABSTRACT: Large-scale oral vaccination of wildlife against rabies using aerial bait distribution has been successfully used to control terrestrial wildlife rabies in Europe and North America. A technical milestone to large-scale oral rabies vaccination campaigns in Europe was the development of fully-automated, computer-supported and cost-efficient technology for aerial distribution of baits like the SURVIS -system. Each bait released is recorded by the control unit through a sensor, with the exact location, time and date of release and subsequently the collected data can be evaluated, e.g. in GIS programmes. Thus, bait delivery systems like SURVIS are an important management tool for flight services and the responsible authorities for the optimization and evaluation of oral vaccination campaigns of wildlife against rabies or the control of other relevant wildlife diseases targeted by oral baits.
No preview · Article · Jun 2012 · Berliner und Münchener tierärztliche Wochenschrift
[Show abstract][Hide abstract]ABSTRACT: In 2005, the final phase of terrestrial rabies eradication in Germany was put at risk by a severe setback due to re-introduction of the disease in Rhineland-Palatinate from neighbouring Hesse after seven years of absence. The rapid westward spread of the disease prompted veterinary authorities to react swiftly and apply a new yet unproven vaccination strategy to rapidly increase herd immunity in an almost unprotected fox population to stop the epidemic. The cornerstones of this emergency oral rabies vaccination strategy, i. e. vaccination intervals, identification of high risk spots, real time epidemiological assessment, capable to eliminate rabies within 13 months after incursion are described here. This strategy may be used as a template to tackle similar emergency situations in Europe in the future.
No preview · Article · Jun 2012 · Berliner und Münchener tierärztliche Wochenschrift
[Show abstract][Hide abstract]ABSTRACT: Oral rabies vaccination (ORV) has become the method of choice in fox rabies control in Europe. During the past three decades fox-mediated rabies virtually disappeared from Western and Central Europe. Following Switzerland, Germany was the second European country to launch ORV field trials on its territory in 1983. This paper provides a historical overview on the emergence of fox rabies in Germany; describing the basic principles and milestones of the German rabies eradication programme and presenting results of two decades of efforts to control the disease in foxes. Also, setbacks as well as country-specific differences and particularities on Germany's long way to rabies elimination in comparison to other European countries are addressed. Since the first field trials in Germany the number of rabies cases steadily decreased from 10 484 in 1983 to three cases recorded in 2006. On February 3rd 2006 the last case of terrestrial rabies in Germany was detected in a fox near the town of Mainz, Rhineland-Palatinate. In 2008, ORV ceased after 25 years and Germany was officially declared as free from terrestrial rabies. The German rabies eradication programme did cost approximately 100 million euro of which 37 million euro were covered by the EU. For the future, efforts should focus on maintaining a rabies free status by implementing measures to prevent reintroduction of terrestrial rabies from endemic countries.
No preview · Article · May 2012 · Berliner und Münchener tierärztliche Wochenschrift
[Show abstract][Hide abstract]ABSTRACT: Following a sustained spill-over event from dogs to foxes, fox rabies spread rapidly in the Aegean region, Turkey. In order to control the outbreak a program of oral vaccination of foxes against rabies was introduced. In the selected vaccination area three annual campaigns between 2008 and 2010 were undertaken during the winter months whereby the vaccine baits were distributed exclusively by plane using a density of 18 baits per km2. Subsequently, fox rabies cases were reported only from locations bordering the non-vaccinated areas. Hence, it was shown that fox rabies control by means of oral rabies vaccination is feasible in Turkey. However, for the progress towards the elimination of fox-mediated rabies in Turkey to be maintained, it is necessary that political and financial support is secured to extend oral vaccination where infected foxes remain.
Full-text · Article · May 2012 · Berliner und Münchener tierärztliche Wochenschrift
[Show abstract][Hide abstract]ABSTRACT: Terrestrial wildlife rabies has been successfully eliminated from Germany predominantly as a result of the distribution of oral rabies vaccine baits. In case that wildlife rabies would re-emerge among its known reservoir species in Germany, swift action based on previous experiences could spatially and temporally limit and subsequently control such an outbreak. However, if rabies emerged in the raccoon population in Germany (Procyon lotor), there are no tools or local experience available to cope with this situation. This is especially worrisome for urban areas like Kassel (Hesse) due to the extremely high raccoon population density. A rabies outbreak among this potential reservoir host species in these urban settings could have a significant impact on public and animal health.
Full-text · Article · May 2012 · Berliner und Münchener tierärztliche Wochenschrift
[Show abstract][Hide abstract]ABSTRACT: Rabies is considered one of the oldest infectious diseases known to humans. However, the first written reports on rabies cases in the Americas did not appear until the first decade of the 18th century from Mexico. In an attempt to clarify if the disease was already present in pre-Columbian times, we searched for evidence in the Maya and Aztec cultures. Other sources of information were early manuscripts written by the conquistadors and early explorers. We did not identify any unequivocal direct evidence that the disease rabies was known in pre-Columbian Central America but sufficient circumstantial evidence is available suggesting that (bat) rabies was already present in these early times.
No preview · Article · Jul 2011 · Epidemiology and Infection
[Show abstract][Hide abstract]ABSTRACT: Rabies is a fatal viral encephalitis and results from infection with viruses belonging to the genus Lyssavirus. Infection usually results from a bite from a dog infected with classical rabies virus. However, a small number of cases result from contact with bats. It is within bats that most lyssavirus variants, referred to as genotypes, are found. The lyssaviruses found in bats have a distinct geographical distribution and are often restricted to specific bat species. Most have been associated with rabies in humans and in some cases spill-over to domestic animals. Many diagnostic techniques are unable to differentiate rabies virus from other genotypes so it is possible that some human and animal cases go unreported. Furthermore, current vaccines have limited efficacy against some genotypes.
Full-text · Article · Feb 2010 · Veterinary Microbiology
[Show abstract][Hide abstract]ABSTRACT: Turkey is the only country in Europe where urban dog-mediated rabies persists. Control measures in recent decades have reduced the burden of rabies to relatively low levels but foci of disease still persist, particularly in urban areas. Occasional human cases result from this persistence although the source of these appears to be both dog and wildlife reservoirs. This review considers the current state of rabies in Turkey including current control measures, the varying epidemiology of the disease throughout this country and the prospects for rabies elimination.
Full-text · Article · Oct 2009 · Epidemiology and Infection
[Show abstract][Hide abstract]ABSTRACT: To eradicate rabies in foxes, almost 97 million oral rabies vaccine baits have been distributed in Germany and Austria since 1983 and 1986, respectively. Since 2007, no terrestrial cases have been reported in either country. The most widely used oral rabies vaccine viruses in these countries were SAD (Street Alabama Dufferin) strains, e.g. SAD B19 (53.2%) and SAD P5/88 (44.5%). In this paper, we describe six possible vaccine-virus-associated rabies cases in red foxes (Vulpes vulpes) detected during post-vaccination surveillance from 2001 to 2006, involving two different vaccines and different batches. Compared to prototypic vaccine strains, full-genome sequencing revealed between 1 and 5 single nucleotide alterations in the L gene in 5 of 6 SAD isolates, resulting in up to two amino acid substitutions. However, experimental infection of juvenile foxes showed that those mutations had no influence on pathogenicity. The cases described here, coming from geographically widely separated regions, do not represent a spatial cluster. More importantly, enhanced surveillance showed that the vaccine viruses involved did not become established in the red fox population. It seems that the number of reported vaccine virus-associated rabies cases is determined predominantly by the intensity of surveillance after the oral rabies vaccination campaign and not by the selection of strains.
No preview · Article · Jul 2009 · Archives of Virology
[Show abstract][Hide abstract]ABSTRACT: The serotine bat (Eptesicus serotinus) accounts for the vast majority of bat rabies cases in Europe and is considered the main reservoir for European bat lyssavirus type 1 (EBLV-1, genotype 5). However, so far the disease has not been investigated in its native host under experimental conditions. To assess viral virulence, dissemination and probable means of transmission, captive bats were infected experimentally with an EBLV-1a virus isolated from a naturally infected conspecific from Germany. Twenty-nine wild caught bats were divided into five groups and inoculated by intracranial (i.c.), intramuscular (i.m.) or subcutaneous (s.c.) injection or by intranasal (i.n.) inoculation to mimic the various potential routes of infection. One group of bats was maintained as uninfected controls. Mortality was highest in the i.c.-infected animals, followed by the s.c. and i.m. groups. Incubation periods varied from 7 to 26 days depending on the route of infection. Rabies did not develop in the i.n. group or in the negative-control group. None of the infected bats seroconverted. Viral antigen was detected in more than 50% of the taste buds of an i.c.-infected animal. Shedding of viable virus was measured by virus isolation in cell culture for one bat from the s.c. group at 13 and 14 days post-inoculation, i.e. 7 days before death. In conclusion, it is postulated that s.c. inoculation, in nature caused by bites, may be an efficient way of transmitting EBLV-1 among free-living serotine bats.
Full-text · Article · Jul 2009 · Journal of General Virology
[Show abstract][Hide abstract]ABSTRACT: Rabies remains endemic in many regions of Turkey. As a consequence, humans are at risk of this fatal disease through encounters with rabid animals. The present study describes four recent cases of rabies in humans. Subsequent phylogenetic analysis of the rabies virus isolates obtained from each case demonstrates the distinct geographical distribution of rabies virus variants within Turkey. The study suggests that rabies virus translocation has occurred across Turkey and might be the source of the emergence of a genetically similar variant in the Golan Heights region on the Israeli/Syrian border in 2004.
[Show abstract][Hide abstract]ABSTRACT: Two common bat lyssavirus species have been identified in many European countries: European bat lyssavirus type-1 and -2 (EBLV-1 and EBLV-2). Only limited knowledge on the susceptibility of the natural EBLV-hosts, insectivorous bats, to lyssavirus infection is available. Our study was undertaken to evaluate the susceptibility and pathology associated with an EBLV-1 infection in Eptesicus fuscus following different routes of virus inoculation including intracranial (n = 6), intramuscular (n = 14), oral (n = 7) and intranasal (n = 7). Blood and saliva samples were collected from all bats on a monthly basis. Four bats inoculated intracranially developed rabies with a mean of 11 days to death, whilst seven bats inoculated intramuscularly developed rabies, with an extended incubation period prior to death. We did not observe any mortality in the oral (p.o.) or intranasal (i.n.) groups and both groups had detectable levels of virus neutralizing antibodies (data not shown). Virus shedding was demonstrated in the saliva by virus isolation and the detection of viral RNA in ill bats, particularly immediately prior to the development of disease. In addition, the presence of virus and viral RNA was detected in the thyroid gland in bats challenged experimentally with EBLV-1, which exceeded that detected in all other extra-neural tissue. The significance of detecting EBLV-1 in the thyroid gland of rabid bats is not well understood. We speculate that the infection of the thyroid gland may cause subacute thyroiditis, a transient form of thyroiditis causing hyperthyroidism, resulting in changes in adrenocortical activity that could lead to hormonal dysfunction, thereby distinguishing the clinical presentation of rabies in the rabid host.
No preview · Article · Jun 2009 · Zoonoses and Public Health
[Show abstract][Hide abstract]ABSTRACT: The aim of this study was to determine the susceptibility of insectivorous bats (using the big brown bat as a model) to infection with European bat lyssavirus type 1a (EBLV-1a), to assess the dynamics of host immune responses and to evaluate the opportunity for horizontal viral transmission within colonies. Two isolates of EBLV-1a, originating from Slovakia (EBLV-1aSK) and Germany (EBLV-1aGE), were tested. Four different routes of inoculation were used with isolate EBLV-1aSK [10(4.8) mouse intracerebral median lethal dose (MICLD(50)) in 50 mul]: intramuscular (i.m.) in the deltoid area or masseter region, per os (p.o.) and intradermal (i.d.) scratches. Isolate EBLV-1aGE (10(3.2) and 10(2.2) MICLD(50) in 20 mul) was inoculated via the intranasal (i.n.), i.m. (low- and high-dose groups, into pectoral muscles); p.o. and intracerebral (i.c.) routes. None of the bats infected by the i.n., p.o. or i.d. route with either virus isolate developed disease during the experiments (91 or 120 days, respectively). Incubation periods were 9-12 days for i.c.-inoculated bats (66 % mortality), 12-33 days for bats inoculated i.m. with the higher dose (23-50 % mortality) and 21-58 days in bats inoculated i.m. with the lower dose of virus (57 % mortality). Virus or viral RNA in bat saliva was detected occasionally, as early as 37 days before death. All i.d.-inoculated and the majority of i.m.-inoculated bats seroconverted within 7-10 days of inoculation. These observations suggest that exposure of bats to varying doses of EBLV-1 from rabid conspecifics via natural (i.d.) routes could lead to an abortive infection and serve as a natural mode of immunization resulting in the presence of virus-neutralizing antibodies in free-ranging bats.
Full-text · Article · Aug 2008 · Journal of General Virology
[Show abstract][Hide abstract]ABSTRACT: Rabies remains endemic within a number of countries in Southeast Europe including Romania, Bulgaria and Turkey. With the probable expansion of the European Union eastwards, it is likely that rabies elimination programs will be increased to reduce the burden of disease in new accession countries. A clear understanding of the epidemiology of the virus in this area of Europe is vital before such programs are introduced. With the exception of Turkey, the red fox (Vulpes vulpes) is the principal disease reservoir in Southeastern Europe. However, cases of rabies in the dog (Canis familiaris) are regularly reported. In contrast to Northern Europe, the raccoon dog (Nyctereutes procyonoides) does not appear to be a vector in the south. This study summarises the current rabies situation in Southeast Europe and demonstrates the phylogenetic relationships between the viruses in a number of the countries within the region. Rabies virus RNA was extracted from original samples and a fragment of the nucleoprotein gene amplified by reverse-transcriptase PCR. Automated sequencing was used to derive nucleoprotein gene sequences and these were used to prepare a molecular phylogeny of rabies viruses in Southeast Europe. In Bulgaria, the dog is the main vector bringing rabies into contact with humans and livestock. However, other species may also act as reservoirs for the disease, complicating the development of elimination strategies. The fox is the principal reservoir species for rabies in Romania although cases in dogs are regularly reported. Despite a gradual decline in dog rabies, urban pockets of the disease remain in many regions of Turkey. Furthermore, there is some evidence that the fox has been a significant vectorfor rabies and may be responsible for increases in rabies in cattle in the Aegean region of the country. Throughout the region there is evidence for cross-border movement of rabies by both wildlife and canine vectors.
Full-text · Article · Jan 2008 · Developments in biologicals
[Show abstract][Hide abstract]ABSTRACT: 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.
Full-text · Article · Jan 2008 · Veterinary Microbiology
[Show abstract][Hide abstract]ABSTRACT: Rabies in European bats was first reported in Germany in 1954. In concordance with Denmark and the Netherlands, Germany has reported one of the highest numbers (n = 187) of European bat lyssavirus (EBLV)-positive cases in bats in Europe so far (1954-2005). A combined descriptive epidemiological and phylogenetic analysis on bat rabies and prevailing EBLVs is presented, comprising the past 50 years. So far, only the two lineages of EBLV-1 (genotype 5), a and b, have been detected. Although only 50% of the rabies-positive bats have been identified by species, the Serotine bat (Eptesicus serotinus) is the bat species most frequently infected. Single rabies cases have also been detected in a further five indigenous bat species. There is proven evidence for a substantial bias in the frequency of bat rabies cases in the north of Germany, with an endemic cluster in the northwesternmost low-lying plain areas adjacent to the Netherlands and Denmark. Improvements to bat rabies surveillance and research are discussed.
Full-text · Article · Mar 2007 · Archives of Virology