Feline and Canine Rabies in New York State,USA

In New York State, domestic animals are no longer considered rabies vector species, but given their ubiquity with humans, rabies cases in dogs and cats often result in multiple individuals requiring post-exposure prophylaxis. For over a decade, the New York State rabies laboratory has variant-typed these domestic animals to aid in epidemiological investigations, determine exposures, and generate demographic data. We produced a data set that outlined vaccination status, ownership, and rabies results. Our data demonstrate that a large percentage of felines submitted for rabies testing were not vaccinated or did not have a current rabies vaccination, while canines were largely vaccinated. Despite massive vaccination campaigns, free clinics, and education, these companion animals still occasionally contract rabies. Barring translocation events, we note that rabies-positive cats and dogs in New York State have exclusively contracted a raccoon variant. While the United States has made tremendous strides in reducing its rabies burden, we hope these data will encourage responsible pet ownership including rabies vaccinations to reduce unnecessary animal mortality, long quarantines, and post-exposure prophylaxis in humans.     

Predicting the spatial dynamics of rabies epidemics on heterogeneous landscapes

Often as an epidemic spreads, the leading front is irregular, reflecting spatial variation in local transmission rates. We developed a methodology for quantifying spatial variation in rates of disease spread across heterogeneous landscapes. Based on data for epidemic raccoon rabies in Connecticut, we developed a stochastic spatial model of rabies spread through the state's 169 townships. We quantified spatial variation in transmission rates associated with human demography and key habitat features. We found that large rivers act as semipermeable barriers, leading to a 7-fold reduction in the local rates of propagation. By combining the spatial distribution of major rivers with long-distance dispersal we were able to account for the observed irregular pattern of disease spread across the state without recourse to direct assessment of host-pathogen populations.     

Genetic divergence of rabies viruses from bat species of Colorado, USA

Molecular epidemiological studies have linked many cryptic human rabies cases in the United States with exposure to rabies virus (RV) variants associated with insectivorous bats. In Colorado, bats accounted for 98% of all reported animal rabies cases between 1977 and 1996. The genetic divergence of RV was investigated in bat and terrestrial animal specimens that were submitted for rabies diagnosis to the Colorado Department of Public Health and Environment (CDPHE), Colorado, USA. RV isolates from animal specimens across the United States were also included in the analysis. Phylogenetic analyses were performed on partial nucleoprotein (N) gene sequences, which revealed seven principal clades. RV associated with the colonial big brown bat, Eptesicus fuscus, an bats of the genus Myotis were found to segregate into two distinct clades (I and IV). Clade I was harbored by E. fuscus and Myotis species, but was also identified in terrestrial animals such as domestic cats and striped skunks (Mephitis mephitis). Clade IV was divided into subclades IVA, IVB, and IVC; IVA was identified in E. fuscus, and Myotis species bats, and also in a fox; subclades IVB and IVC circulated predominantly in E. fuscus. Clade II was formed by big free-tailed bat (Nyctinomops macrotis) and striped skunk (Mephitis mephitis) samples. Clade III included RVs that are maintained by generally solitary, migratory bats such as the silver-haired bat (Lasionycteris noctivagans) and bats of the genus Lasiurus. Big brown bats were found to harbor this RV variant. None of the Colorado specimens segregated with clades V and VII that harbor RVs associated with terrestrial animals. Different species of bats had the same RV variant, indicating active inter-species rabies transmission. In Colorado, animal rabies occurs principally in bats, and the identification of bat RVs in cat, gray fox Urocyon cinereoargenteus), and striped skunks demonstrated the importance of rabies spillover from bats to domestic and terrestrial wildlife species.     

Rabies in a nine-year-old child: The myth of the bite

A nine-year-old boy died from rabies encephalitis caused by a rabies virus variant associated with insectivorous bats. The patient was most likely infected in the Laurentian Mountains of western Quebec, but neither the patient nor his parents remembered any direct contact with an animal. The diagnosis was made seven days after the start of symptoms. After examining the most recent cases of rabies in North America, it is obvious that rabies following bat exposure can occur without history of a documented bite. The present case report emphasizes that the general public and medical care providers need better information about the risks associated with exposure to bats.Key Words: Bat, Children, Encephalitis, Prophylaxis, RabiesRabies is a zoonosis responsible for more than 50,000 human deaths every year worldwide, as reported by the World Health Organization. In North America and Europe, human rabies has become a very rare disease, because of the systematic vaccination of domestic animals, massive vaccination campaigns of wild animals, efficacy of rabies postexposure prophylaxis (RPEP) and education programs (1,2). While knowledge about the risk of rabies associated with a bite from a terrestrial animal seems relatively adequate among the general public and medical care providers, a lack of information may exist regarding the risk of human rabies following contact with a bat. Between 1980 and 1996, 32 cases of human rabies were diagnosed in the United States, 17 of which occurred after a contact with an indigenous bat (of which only two patients had a definite bite), 14 cases after a dog bite and one after a skunk bite (3). In Canada, three of the four cases of human rabies that have occurred since 1970 followed exposure to bats, the last case dating to 1985 (4). Since September 2000, five cases of human rabies have been reported in the United States (5). One was consecutive to a dog bite contracted in Africa and four have been attributed to bats; in the latter cases, a definite history of a bite was noted in only one case. In 1996, the National Association of State Public Health Veterinarians of the United States stated that "since rabies is endemic in bats, bats should be excluded from houses and surrounding structures to prevent direct association with humans" (6). Possible measures to reduce the bat population to a critical threshold below which the virus might be unable to propagate or to induce immunity in the vector via vaccination seem physically, economically and ecologically impractical (7). The case that we report emphasizes that the bite or the scratch of a rabid bat can go unnoticed and may lead to the development of human rabies.     

Epidemiology and prevention of animal bite and human rabies in a rural community-One health experiment

ObjectiveTo estimate the incidence of human rabies and animal bite/exposure; to describe the post exposure prophylaxis received by animal bite/exposure cases; to assess the safety and immunogenicity of rabies vaccine (purified chick embryo cell vaccine) administered as pre-exposure vaccination for school children and risk groups by intradermal route in the rural community and to demonstrate a decrease in the incidence of human rabies and animal bite/exposures through implementation of one health experiment.MethodsThis prospective interventional study was conducted over a period of 2 years (December 2009-November 2011) in a rural area near Bangalore, Karnataka, South India and consisted of six villages (project villages), three villages were identified as study villages with active interventions (Implementation of rabies awareness activities, post exposure prophylaxis, pre-exposure intradermal rabies vaccine) and three villages as control villages without any active interventions.ResultsA majority of the animal bite cases were category III exposures and all of them had received rabies immunoglobulin and anti-rabies vaccine as per WHO recommendation. A majority received 3 to 5 doses of vaccine. Three hundred and sixty eight subjects had received pre-exposure intradermal rabies vaccination thrice on days 0, 7 and 28 d.ConclusionsNo human rabies case was reported during the study period and there was 30% decrease in animal bite/exposure cases in study villages after the one health experiment project was implemented. Pre-exposure vaccination was safe and immunogenic.     

Rabies epizootics among raccoons vary along a North-South gradient in the Eastern United States

The characteristics of rabies epizootics among raccoons were investigated in 11 eastern states along a North-South gradient from New York to North Carolina. Epizootics were defined as discrete intervals of time of at least 5 months in duration, when reported cases of raccoon rabies from an individual county exceeded the median value of raccoon rabies cases reported by that county over the entire period rabies was present among raccoons in the county. Over the approximately 20-year study period, 35,000 cases of raccoon rabies were reported, and epizootics were detected from 251 (64.4%) of 390 counties. The median annual incidence was 0.14 epizootics per year. During the first defined epizootic in a county, the median total number of raccoons reported rabid was 47, with a median monthly incidence of rabies in raccoons of 3.1. The median lag time from the first report of a rabid raccoon in a county to the beginning of the first epizootic was 4 months. Significant differences in the annual incidence of epizootics and monthly incidence of rabid raccoons during epizootics were observed among different states. Although human population density and per capita health spending within counties were positively associated with increasing magnitude of epizootics, a significant difference in the characteristics of rabies epizootics in northern and southern states was apparent. We hypothesize that environmental conditions and perhaps human influence resulted in rabies epizootics in southern states that were smaller, less-frequent, and lacking in well-defined temporal structure compared with those in northern states.     

A spatial model to forecast raccoon rabies emergence

Although raccoons are widely distributed throughout North America, the raccoon rabies virus variant is enzootic only in the eastern United States, based on current surveillance data. This variant of rabies virus is now responsible for >60% of all cases of animal rabies reported in the United States each year. Ongoing national efforts via an oral rabies vaccination (ORV) program are aimed at preventing the spread of raccoon rabies. However, from an epidemiologic perspective, the relative susceptibility of na?ve geographic localities, adjacent to defined enzootic areas, to support an outbreak, is unknown. In the current study, we tested the ability of a spatial risk model to forecast raccoon rabies spread in presumably rabies-free and enzootic areas. Demographic, environmental, and geographical features of three adjacent states (Ohio, West Virginia, and Pennsylvania), which include distinct raccoon rabies free, as well as enzootic areas, were modeled by using a Poisson Regression Model, which had been developed from previous studies of enzootic raccoon rabies in New York State. We estimated susceptibility to raccoon rabies emergence at the census tract level and compared the results with historical surveillance data. Approximately 70% of the disease-free region had moderate to very high susceptibility, compared with 23% in the enzootic region. Areas of high susceptibility for raccoon rabies lie west of current ORV intervention areas, especially in southern Ohio and western West Virginia. Predicted high susceptibility areas matched historical surveillance data. We discuss model implications to the spatial dynamics and spread of raccoon rabies, and its application for designing more efficient disease control interventions.     

Rabies in a nine-year-old child: The myth of the bite.

A nine-year-old boy died from rabies encephalitis caused by a rabies virus variant associated with insectivorous bats. The patient was most likely infected in the Laurentian Mountains of western Quebec, but neither the patient nor his parents remembered any direct contact with an animal. The diagnosis was made seven days after the start of symptoms. After examining the most recent cases of rabies in North America, it is obvious that rabies following bat exposure can occur without history of a documented bite. The present case report emphasizes that the general public and medical care providers need better information about the risks associated with exposure to bats.     

Confirmed rabies exposure during pregnancy: treatment with human rabies immune globulin and human diploid cell vaccine

A review of the literature shows 24 cases of pregnant human exposure to rabies virus through confirmed rabid animal bites. Historically, these patients received passive immunization with equine rabies immunoglobulin and/or purified vero cell vaccine or duck embryo vaccine. With the recent development of human-derived rabies vaccines, we report an additional case of human gestational rabies exposure, which was treated with human rabies immune globulin and human diploid cell vaccine.     

The Successful Elimination of Sylvatic Rabies Using Oral Vaccination of Foxes in Slovenia

Sylvatic rabies was present in Slovenia between 1973 and 2013, with the red fox as the main reservoir of the rabies virus. The first oral rabies vaccination (ORV) control program in foxes started in 1988, using the manual distribution of baits. Significant improvement of fox vaccination was achieved with the aerial distribution of baits, starting in 1995 and successfully finished with the final, fifty-ninth vaccination campaign in 2019. Between 1979 and 2019, a total of 86,471 samples were tested, and 10,975 (12.69%) rabies-positive animals were identified. Within the ORV, two different vaccines were used, containing modified live virus strain Street Alabama Dufferin (SAD) B19 and SAD Bern, while the last ORV campaigns were completed in 2019, with a vaccine containing a genetically modified strain of SPBN GASGAS. Molecular epidemiological studies of 95 rabies-positive samples, originating from red foxes, badgers, cattle, dogs, martens, cats, and horses, revealed a low genetic diversity of circulating strains and high similarity to strains from neighboring countries. During the elimination program, few vaccine-induced rabies cases were detected: three in red foxes and one case in a marten, with no epidemiological relevance. Slovenia has been officially declared a country free of rabies since 2016.     

BAT-BORNE RABIES IN LATIN AMERICA

The situation of rabies in America is complex: rabies in dogs has decreased dramatically, but bats are increasingly recognized as natural reservoirs of other rabies variants. Here, bat species known to be rabies-positive with different antigenic variants, are summarized in relation to bat conservation status across Latin America. Rabies virus is widespread in Latin American bat species, 22.5%⁷⁵ of bat species have been confirmed as rabies-positive. Most bat species found rabies positive are classified by the International Union for Conservation of Nature as “Least Concern”. According to diet type, insectivorous bats had the most species known as rabies reservoirs, while in proportion hematophagous bats were the most important. Research at coarse spatial scales must strive to understand rabies ecology; basic information on distribution and population dynamics of many Latin American and Caribbean bat species is needed; and detailed information on effects of landscape change in driving bat-borne rabies outbreaks remains unassessed. Finally, integrated approaches including public health, ecology, and conservation biology are needed to understand and prevent emergent diseases in bats.     

Assessment of rabies exposure risk among Israeli travelers

BACKGROUND: The decision whether or not to administer rabies pre-exposure prophylaxis (PEP) to travelers visiting endemic areas is a complex one. Paramount for making that decision is knowledge of the risk of animal bites during travel. This study attempts to estimate the risk of bites in travelers, and study the action they took before and after the incident. METHODS: Travelers presenting for pre-travel immunizations during the period of August through December 2004, who planned a travel of >or= 1 month's duration were retrospectively identified, contacted and interviewed by a structured questionnaire. These travelers did not receive specific advice concerning rabies. RESULTS: The study cohort comprised of 815 travelers (median age=25), of who 13 (1.6%) were injured by a potentially rabid animal (mainly, dog=6; monkey=4). The incidence of potential rabies exposure was found to be of 2.66 per 1000 travelers per month. Those injured had significantly longer trips than the non-injured (6.9+/-3.8 vs. 4+/-5.0 months, p=0.037); notably, the injuries occurred after a median of 5 weeks from departure. Although seven travelers noted blood at the site of injury, only four (31%) of the injured sought medical attention following the exposure, and all four received post-exposure prophylaxis. CONCLUSIONS: An injury by potentially rabid animals is not rare among long-term travelers. As the injury may occur early in the itinerary, rabies PEP should be considered for this population. Educational efforts are required in light of the lack of understanding of the dismal consequences of rabies among travelers.     

Rabies in wildlife in Latvia

In the Baltic States, lyssaviruses are often detected in wildlife and presumed to constitute an important public health hazard. In order to decrease rabies incidence and eradicate wildlife reservoirs, a national rabies eradication program has been in place. Since 1970 a vaccination program in dogs and cats has been executed, and in 1991 oral vaccination of foxes was started. However, due to an insufficient budget, the latter was not done regularly and nationwide before 2000. Now, the program in force consists of compulsory vaccination of all dogs and cats, and a tetracycline marker vaccine oral vaccination program of foxes in the whole country. In 2001, 151 of 285 (53%) fox jaws were tested positive for tetracycline. All animals showing rabies-like symptoms were killed and tested for rabies. In this way, 250-400 cases of rabies per year were diagnosed in wildlife. To molecularly characterize the prevalent lyssaviruses in wildlife, lyssavirus RNA of 25 recent rabies positive samples, collected in the year 1999, was amplified by RT-PCR. Direct sequencing of the RT-PCR-amplified products of the virus' nucleoprotein encoding region and subsequent sequence analyses resulted in a 99.3-100% homology between isolates and a 99.0-100% similarity with a 1995 genotype I, classical rabies virus (RABV) raccoon dog isolate from Estonia. These results confirmed that RABV is endemic in wildlife in Latvia and should be considered a serious public health threat. To successfully eradicate the wildlife reservoirs, the national rabies eradication program must be continued, and it may need to be intensified.     

云南省德宏州狂犬病流行病学特点及防控效果分析

目的分析云南省德宏州狂犬病流行特征及防控效果,为防治策略的制定提供科学依据。方法收集德宏州动物和人间狂犬病疫情及防控工作资料,进行描述流行病学分析和防控效果评价。结果2002-2010年德宏州发生动物狂犬病疫情52起,人狂犬病发病死亡17例,疫情波及3个县15个乡镇17个自然村;人间病例多因被狂犬咬伤后未进行规范处置而发病死亡,常发生由缅甸输入的狂犬病疫情;采取多部门联防联控,犬类“管、免、灭”为主的综合防控措施,疫情得到一定程度控制。结论德宏州存在狂犬病自然疫源地,犬间疫情常有发生,疫情态势仍较严峻;应全面落实宣传教育、规范暴露后预防处置和犬类管理、免疫以及防止境外疫情输入等综合防控措施。     

西安市6 635例狂犬病暴露者流行病学调查

目的 分析西安市2016-2017年来6 635例狂犬病暴露者流行特征,探讨相关危险因素,为狂犬病的防治提供依据。方法 对狂犬病暴露者按年龄、性别、职业、暴露时间、暴露地点、暴露动物、暴露部位、暴露级别和处置及发病情况等进行统计分析。结果 6-10月为狂犬病暴露高发季节,共暴露4 038例,占60.86%;犬和猫为主要致伤动物,占66.25%和30.49%;暴露男女比为1∶1.19;20~岁及10~岁年龄组暴露最多,占33.56%和16.38%;暴露者以自由职业者、学生及服务业从业者居多,分别占总26.36%、21.75%和15.33%;暴露地点主要在家中,占67.94%;暴露部位以上、下肢为主,分别占43.48%和38.63%;以III级暴露为主,占80.24%;暴露后规范处置率达100%,狂犬病疫苗接种率达100%,疫苗全程接种率为99.83%,III级暴露后被动免疫制剂注射率为52.95%。结论 西安市面临着严峻的狂犬病防控压力,其狂犬病暴露流行病学特征与周边地区及陕西省全省不尽相同,有自己的特点,应重点加强宠物犬猫的免疫与管理,消灭流浪犬猫;针对不同人群特点加强狂犬病预防及处置知识的健康教育,提高其预防意识和认知水平;进一步加强犬伤处置门诊规范化建设。     

Predicting the local dynamics of epizootic rabies among raccoons in the United States

Mathematical models have been developed to explore the population dynamics of viral diseases among wildlife. However, assessing the predictions stemming from these models with wildlife databases adequate in size and temporal duration is uncommon. An epizootic of raccoon rabies that began in the mid-Atlantic region of the United States in the late 1970s has developed into one of the largest and most extensive in the history of wildlife rabies. We analyzed the dynamics of local epizootics at the county level by examining a database spanning more than 20 years and including 35,387 rabid raccoons. The size, number, and periodicity of rabies epizootics among raccoons were compared with predictions derived from a susceptible, exposed, infectious, and recovered model of raccoon rabies [Coyne, J., Smith, G. & McAllister, F. E. (1989) Am. J. Vet. Res. 50, 2148-2154]. After our methods for defining epizootics were applied to solutions of the model, the time series revealed recurrent epizootics in some counties, with a median first epizootic period of 48 months. Successive epizootics declined in size and the epizootic period progressively decreased. Our reanalysis of the model predicted the initial-epizootic period of 4-5 years, with a progressive dampening of epizootic size and progressive decrease in epizootic period. The best quantitative agreement between data and model assumed low levels of immunity (1-5%) within raccoon populations, suggesting that raccoons develop little or no rabies immune class. These results encourage the use of data obtained through wildlife surveillance in assessing and refining epidemic models for wildlife diseases.     

2007年福建省疾病预防控制中心犬伤门诊病例流行病学分析

目的分析被动物咬伤到犬伤门诊就诊病例的流行病学因素,为加强狂犬病防治工作提供依据。方法采用描述性研究方法,对狂犬病暴露病例的性别、年龄、就诊时间、暴露级别、伤口处理、狂犬病疫苗及人狂犬病免疫球蛋白接种及时性以及伤人动物类别等因素进行统计分析;结果2007年福建省疾病控制中心犬伤门诊共接诊4 128例,其中10岁以下儿童和21~41岁年龄组被咬伤人数最多;暴露者能在5h内及时就诊的仅占14.22%;使用狂犬病免疫球蛋白人数占应使用者的14.27%;宠物犬咬伤占64.27%。结论必须加强对群众的狂犬病防治知识的宣传教育,普及狂犬病的防治知识,加强全省犬的管理,在被动物致伤后应及时清洗伤口,并及时到疾病预防控制机构或医疗机构接种狂犬病疫苗和狂犬病免疫球蛋白。     

An important public health problem: rabies suspected bites and post-exposure prophylaxis in a health district in Turkey.

OBJECTIVE: The aim of this study was to describe rabies suspected animal bites and post-exposure prophylaxis (PEP) practices in Narlidere District in Turkey between 1999 and 2001. METHODS: One thousand five hundred and sixty-nine rabies suspected bite cases reported were identified from the District's rabies surveillance forms. RESULTS: Males comprised 66.7% of the cases, and 43.5% of the total were under 20 years old. In 74% of cases the animal involved in the bite was a dog. Only 70% of the animals had an owner, and only 17% of the animals had a rabies vaccination certificate. In terms of treatment, 68% of the human cases received PEP, and 21% of cases had an extra (sixth) vaccination dose, which is a substantial burden on the healthcare system, costing half a million US dollars per year. The place where the bite occurred (rural areas), the age of the recipient (more than 10 years old), the animal type (animals other than dogs and cats), lack of a vaccination certificate for the animal, and place of wound treatment (hospital) were significantly associated with PEP application. CONCLUSIONS: In addition to the currently recommended strategy of controlling the dog population and of vaccinating domesticated animals, adults and children should be educated about bite prevention to reduce the number of animal bites.     

Rabies: Still a Uniformly Fatal Disease? Historical Occurrence, Epidemiological Trends, and Paradigm Shifts

Rabies has the highest case fatality of any infectious disease. Pathobiological and clinical insights have questioned the assertion that death is inevitable after onset of acute encephalomyelitis. Relying upon national laboratory-based surveillance, we reviewed records of human rabies acquired in the United States during 1960-2009. Changes in the epidemiology of human rabies were notable, due to improved animal management, safer and more efficacious biologics, and revisions in prevention guidelines. Historically, domestic animals were the most important source of infection. Since the 1990s, more human cases were associated with rabid bats. Prior to 1980, postexposure prophylaxis failures were reported. After development of modern rabies immune globulin and vaccines, none occurred. Of 75 human cases identified, only four patients survived. Rabies remains an extremely high consequence zoonosis, but the disease is not uniformly fatal, per se. Rabies is essentially preventable when primary exposures are averted, or appropriate prophylaxis occurs before illness.     

Rabies in Oyo State, Nigeria; 1971-1982

Epidemiologic data gathered from recorded sources in Oyo State, Nigeria, indicates that people are at 2.1 times greater risk there than in Africa generally and 56 times greater than in the United States of America of dying from rabies. Women older than 30 years of age comprised 45% (5/12) of the analyzable rabies cases from 1971 to 1979. Two of these 12 cases were contracted from cat bites and both of these cases were women. The reason for the high rate of rabies in Women (7/12), especially older women, is not known although this may relate to their socio-economic role in this part of Nigeria. Nor is it understood why women are more likely to be bitten by rabid cats. Eighty-seven percent of rabid animals were dogs. Males were at greater wisk of being bitten by an animal than were females at a ratio of 1.8 to 1, but 57% of male and 49% of female bite victims were 14 years of age or lress. Women 35-39 years old were bitten more frequently than would be expected from the dminishing rate displayed with increasing age, and this may explain, at least partially, their involvement in fatal rabies. There were an average of 45 to 50 cases of animal bites reported in Oyo State each month from January 1978 through December 1981, and a drastic rise was seen in January through April of 1980. There was not a parallel increase in human rabies during this 4 month period, however. A wildlife reservoir for rabies was not evident from the Oyo State data and it must be presumed that dogs are the maintenance reservoir for the virus. Questionnaire surveys were not useful during this study, but personal interview and trace-back efforts to gather information were valuable. These latter efforts suggest that rabies is more prevalent than existing records indicate, probably by a factor ranging from 2 to 6 or more. Rabies control in Oyo State will require recording and systematic reporting of human and animal cases to develop meningful programs. These all in turn revolve around the societal recognition and determination to cope with the problem.