Rabies-infected Dogs Research Articles

Probable paralytic rabies in a dog: ante-mortem clinical diagnosis implications in limited resource settings.

Rabies is a dreadful zoonotic viral disease that affects animals and humans with a fatality rate of 100%. This report aims to create awareness among the veterinarians and general public about the paralytic form of rabies in order to understand the antemortem clinical diagnosis implications in limited resource settings, so as to follow the post-exposure prophylaxis at the golden hour period of rabies transmission. A one-year-old female dog was presented to the Ambulatory Clinic Unit, Veterinary Clinical Complex, Veterinary College and Research Institute, Theni, Tamil Nadu, India with the ailment of a dropped jaw and was unable to swallow food and water for the past three days. Epidemiological investigations revealed that the animal had dog-bitten wounds from a week ago. On clinical examination, facial distortion, changes in the vocal cord, and paralysis of the throat muscle were noticed. Based on the anamnesis, clinical, and epidemiological investigations, the animal was diagnosed to be a probable case of paralytic form of canine rabies. In the limited resource settings, antemortem clinical diagnosis was practiced to suspect rabies-infected dogs. Further, the owner was advised to implement preventive measures to safeguard against rabies infection. The dog was kept under isolation and succumbed on day two with evidence of progressive paralytic signs. This report emphasizes the importance of paralytic rabies, alongside of furious form of rabies, further creating awareness among the general public about the antemortem clinical diagnosis under limited resource settings.

Rabies in an imported dog, Ontario, Canada, 2022.

Importation of rabies-infected dogs results in significant and costly public and animal health risks. In January 2022, a dog in Ontario, Canada, which was imported from Iran in June 2021, developed rabies, leading to an extensive public health investigation and administration of rabies post-exposure prophylaxis to 37 individuals. The dog was infected with a rabies virus variant known to circulate in Iran. This is the second reported case of a rabies-infected dog imported into Canada in 2021 from a high-risk country for canine mediated rabies. This case emphasizes the need for public education regarding the risks associated with importing dogs from high-risk countries for canine-mediated rabies and the benefits of establishing a public health team specializing in rabies exposure investigations.

Effect of Vaccination and Culling on the Dynamics of Rabies Transmission from Stray Dogs to Domestic Dogs

In this paper, the population dynamics of rabies-infected dogs are studied. The mathematical model is constructed by dividing the dog population into two categories: stray dogs and domestic dogs. On the other hand, the rabies virus is likely to spread in both populations. In the current model, disease-controlling strategies such as vaccination and culling are applied, and their impact is studied. Both subpopulations of susceptible individuals are vaccinated to control disease spread. The current study assumes that stray dogs can transmit rabies to domestic dogs but not the other way around. Because domestic dogs are under the control of their owners, they are well vaccinated. The model is medically and analytically correct because the findings are idealistic and limited. The next-generation matrix technique is used to compute the effective reproductive amount, and also, each parameter is subjected to sensitivity analysis. The equilibrium point free from disease is discovered, demonstrating that it was asymptotically steady locally and globally. A conditionally global asymptotically stable point of endemic equilibrium is also discovered using the Lyapunov function method. The numerical simulation, which makes use of approximations for parameter values, shows that the most efficient method for avoiding rabies transmission is a combination of vaccination and the culling of infected stray dogs. Using MATLAB’s ode45, this numerical simulation investigation was carried out. Our early findings indicated that the annual dog birth rate is a critical factor in influencing the occurrence of rabies. In the body of the paper, the findings and discussion are organized logically.

Rabies-infected dogs at slaughterhouses: A potential risk of rabies transmission via dog trading and butchering activities in Vietnam.

The study aimed to determine the status of neutralizing antibodies and rabies virus infection in dogs at slaughterhouses in Hanoi city from 2015 to 2017. A total of 2,376 pairs of blood and brain samples were collected from dogs at 92 slaughterhouses (8 large slaughterhouses and 84 small slaughterhouses) in 6 districts in Hanoi. Of the 1,500 dog samples from the large slaughterhouses where imported dogs were slaughtered, no dog brain samples were infected with rabies virus and no blood samples were positive for rabies neutralizing antibodies. Meanwhile, 7/876 (0.8%) of dog brain samples from small slaughterhouses in which slaughtered local dogs were positive for rabies virus and 26.4% had neutralizing antibodies against rabies virus. Analysis of the genetic characteristics of these rabies viruses showed that they all had a common origin with the domestic strains circulating in Northern Vietnam. Research results suggested that there was a potential risk of rabies transmission to humans through dog slaughtering activities in Vietnam. Vaccination for dogs should be strengthened, strictly implemented and frequently monitored to reach the rate of herd vaccination coverage as WHO's recommendation. Dog trading and slaughtering activities should be strictly monitored to minimize the risk of rabies transmission to humans.

Risk assessment on rabies entry through hunting dog movement with semi-quantitative approach to Sumatera Island, Indonesia.

Objective:The objective of this study was to assess the risk of rabies entry through the movement of hunting dog from Garut District to Sumatera Island with a semi-quantitative approach.Materials and Methods:Rabies entry assessment used the standard risk analysis according to the World Organization for Animal Health, with a semi-quantitative approach referring to Australian Biosecurity. Risk estimation calculation used Microsoft Excel and probabilities were estimated using Monte Carlo stochastic simulation modeling with @Risk (Palisade Corporation).Results:Risk estimation were considered as “very low” with a 0.02 (90%; 0.01–0.03) probability. The probability of undetected rabies-infected dog during Veterinary Certificate issuance [node probability (NP4)] was considered as the highest, with “moderate” likelihood and 0.63 (90%; 0.51–0.75) of probability value. The number of dog movement to Sumatera reached 27,000 heads per year which 5,050 heads of them come from Garut District. There were 2 of 100 dogs from Garut District entered to Sumatera possibly infected by rabies. The five highest parameters most determinant of the risk were dog vaccination before transported (0.66), dog obtained from other District (0.41), vaccination program (0.32), serologically test (0.27), and history of vaccination (0.23).Conclusion:Risk estimation from assessing on rabies entry to Sumatera through hunting dogs movement from Garut District was considered “very low.” Risk mitigation is focused on the highest parameters that contribute the most to risk based on the results of the sensitivity analysis. Semi-quantitative likelihood evaluations can consider the volume of dog traffic which is an important issue in risk analysis which is not easy to get with a simpler qualitative approach.

Development of non-governmental organisation-academic partnership to tackle rabies in Africa and Asia.

Rabies kills approximately 60,000 people each year, mainly in sub-Saharan Africa and Asia, of which 40% of victims are less than 15 years old. Once clinical signs develop, the disease is almost invariably fatal. Globally, rabies has been estimated to cause 3∙7 million disability-adjusted life years and $8∙6B in economic losses annually. The vast majority of human rabies cases are caused by bites from rabies-infected dogs. Despite this loss of human life and resultant economic and societal costs, rabies can be prevented in both humans and dogs by vaccination. This has been demonstrated in many countries, notably in Central and South America, where large-scale, high coverage mass dog vaccination programmes have dramatically reduced the incidence of rabies. Even in parts of Africa and Asia, projects have shown that rabies can be eliminated locally. Nevertheless, rabies remains an important cause of mortality in many sub-Saharan and Asian countries. The reasons why some countries have been able to effectively eliminate rabies whereas others have not are complex and often impossible to definitively identify; commonly cited explanations include political, economic, logistical and societal barriers.

Barriers of attendance to dog rabies static point vaccination clinics in Blantyre, Malawi.

Rabies is a devastating yet preventable disease that causes around 59,000 human deaths annually. Almost all human rabies cases are caused by bites from rabies-infected dogs. A large proportion of these cases occur in Sub Saharan Africa (SSA). Annual vaccination of at least 70% of the dog population is recommended by the World Health Organisation in order to eliminate rabies. However, achieving such high vaccination coverage has proven challenging, especially in low resource settings. Despite being logistically and economically more feasible than door-to-door approaches, static point (SP) vaccination campaigns often suffer from low attendance and therefore result in low vaccination coverage. Here, we investigated the barriers to attendance at SP offering free rabies vaccinations for dogs in Blantyre, Malawi. We analysed data for 22,924 dogs from a city-wide vaccination campaign in combination with GIS and household questionnaire data using multivariable logistic regression and distance estimation techniques. We found that distance plays a crucial role in SP attendance (i.e. for every km closer the odds of attending a SP point are 3.3 times higher) and that very few people are willing to travel more than 1.5 km to bring their dog for vaccination. Additionally, we found that dogs from areas with higher proportions of people living in poverty are more likely to be presented for vaccination (ORs 1.58-2.22). Furthermore, puppies (OR 0.26), pregnant or lactating female dogs (OR 0.60) are less likely to be presented for vaccination. Owners also reported that they did not attend an SP because they were not aware of the campaign (27%) or they could not handle their dog (19%). Our findings will inform the design of future rabies vaccination programmes in SSA which may lead to improved vaccination coverage achieved by SP alone.

Going viral in PNG – Exploring routes and circumstances of entry of a rabies-infected dog into Papua New Guinea

In this qualitative study implemented in November 2016, we elicited narratives about fictional rabies incursions from key employees (n = 16) of the National Agriculture and Quarantine Inspection Authority in Papua New Guinea (PNG) to explore the potential circumstances and routes of entry of a rabies-infected dog, and direct rabies preparedness. Although PNG is rabies free, proximity to rabies-endemic Indonesia poses a risk of introduction and it is expected that an outbreak in PNG would have devastating human health impacts consistent with other countries with similarly low human development indices and abundant free-roaming dogs. Participants used their local and professional knowledge to create plausible narratives in response to contextual, but fictitious, newspaper stories. An ethnographic content analysis was used to extract themes and interpret the narratives. Themes were assessed in the context of their potential influence on rabies preparedness in PNG against the social and political background of PNG and relevant, published literature. Consistent themes included the ubiquity of trade and the complexity of routes between Indonesia and PNG. Dog ownership seemed pragmatic – actors in the narratives readily and rationally involved dogs in transactions in response to trade, exchange or gifting opportunities. Consequently, dogs changed ownership frequently. The findings of this study have important implications for rabies preparedness in PNG; there is potential for wide geographic dissemination of rabies in dogs before outbreak detection. However, common patterns of travel – trade of dogs via Papuan towns and use of traditional trade routes – do provide opportunity for targeted surveillance and response in the event of an incursion.

Assessing the Risk of a Canine Rabies Incursion in Northern Australia.

Rabies is a globally distributed virus that causes approximately 60,00 human deaths annually with >99% of cases caused by dog bites. Australia is currently canine rabies free. However, the recent eastward spread of rabies in the Indonesian archipelago has increased the probability of rabies entry into northern Australian communities. In addition, many northern Australian communities have large populations of free-roaming dogs, capable of maintaining rabies should an incursion occur. A risk assessment of rabies entry and transmission into these communities is needed to target control and surveillance measures. Illegal transportation of rabies-infected dogs via boat landings is a high-risk entry pathway and was the focus of the current study. A quantitative, stochastic, risk assessment model was developed to evaluate the risk of rabies entry into north-west Cape York Peninsula, Australia, and rabies introduction to resident dogs in one of the communities via transport of rabies-infected dogs on illegal Indonesian fishing boats. Parameter distributions were derived from expert opinion, literature, and analysis of field studies. The estimated median probability of rabies entry into north-west Cape York Peninsula and into Seisia from individual fishing boats was 1.9 × 10−4/boat and 8.7 × 10−6/boat, respectively. The estimated annual probability that at least one rabies-infected dog enters north-west Cape York Peninsula and into Seisia was 5.5 × 10−3 and 3.5 × 10−4, respectively. The estimated median probability of rabies introduction into Seisia was 4.7 × 10−8/boat, and the estimated annual probability that at least one rabies-infected dog causes rabies transmission in a resident Seisia dog was 8.3 × 10−5. Sensitivity analysis using the Sobol method highlighted some parameters as influential, including but not limited to the prevalence of rabies in Indonesia, the probability of a dog on board an Indonesian fishing boat, and the probability of a Seisia dog being on the beach. Overall, the probabilities of rabies entry into north-west Cape York Peninsula and rabies introduction into Seisia are low. However, the potential devastating consequences of a rabies incursion in this region make this a non-negligible risk.

Risk assessment of the entry of canine-rabies into Papua New Guinea via sea and land routes

Canine-rabies is endemic in parts of Indonesia and continues to spread eastwards through the Indonesian archipelago. Papua New Guinea (PNG) has a land border with Papua Province, Indonesia, as well as logging and fishing industry connections throughout Asia. PNG has a Human Development Index of 0.505; therefore, an incursion of canine-rabies could have devastating impacts on human (7.5 million) and animal populations. Given the known difficulties of rabies elimination in resource-scarce environments, an incursion of rabies into PNG would also likely compromise the campaign for global elimination of rabies. A previous qualitative study to determine routes for detailed risk assessment identified logging, fishing and three land-routes (unregulated crossers [“shopper-crossers”], traditional border crossers and illegal hunters) as potential high risk routes for entry of rabies-infected dogs into PNG. The objective of the current study was to quantify and compare the probability of entry of a rabies-infected dog via these routes into PNG and to identify the highest risk provinces and border districts to target rabies prevention and control activities.Online questionnaires were used to elicit expert-opinion about quantitative model parameter values. A quantitative, stochastic model was then used to assess risk, and parameters with the greatest influence on the estimated mean number of rabies-infected dogs introduced/year were identified via global sensitivity analysis (Sobol method). Eight questionnaires – including 7 online – were implemented and >220 empirical distributions were parameterised using >2900 expert-opinions. The highest risk provinces for combined sea routes were West Sepik, Madang and Western Province, driven by the number of vessels and the probability of bringing dogs. The highest risk border districts for combined land routes were Vanimo-Green River and South Fly, driven by the number of people crossing the border and the number of dogs (with hunters). Overall, the risk posed by land routes was much higher than the risk of rabies introduction by sea routes.This study provides a foundation to develop targeted border control measures, surveillance and response strategies for canine-rabies for the highest risk routes and regions in PNG. Sensitivity analysis using the Sobol method played a key role in this study and directed further data collection to refine risk estimates. The ease of expert-elicitation using online methods demonstrates the feasibility of using such methods for animal and human disease surveillance in PNG.

Quantitative risk assessment of the introduction of rabies into Japan through the illegal landing of dogs from Russian fishing boats in the ports of Hokkaido, Japan

Japan has been free from rabies since 1958 and various preventive measures are in place protecting the country from the introduction of the disease. Historical reviews indicate that the illegal landing of dogs from Russian fishing boats in the ports of Hokkaido occurred frequently especially in the early 2000s and this could potentially be a source of introduction of rabies into Japan. The method of scenario tree modelling was used and the following entry and exposure pathway was considered the most likely route of rabies entry: a rabies-infected dog arriving on a Russian fishing boat lands in a port of Hokkaido in Japan, it becomes infectious, contacts and infects a susceptible domestic animal (companion dog, stray dog or wildlife). Input parameter values were based on surveys of Russian fishermen, expert opinion and scientific data from the literature. At present (2006–2015), the probability of the introduction of rabies as a result of one Russian fishing boat arriving at a port of Hokkaido is 8.33×10−10 (90% Prediction Interval (PI): 7.15×10−11–5.34×10−9), while this probability would have been 7.70×10−9 (90% PI: 6.40×10−10–4.81×10−8) in the past (1998–2005). Under the current situation (average annual number of boat arrivals is 1106), rabies would enter Japan every 1,084,849 (90% PI: 169,215–20,188,348) years, while the disease would have been introduced every 18,309 (90% PI: 2929–220,048) years in the past (average annual number of boat arrivals is 7092). The risk of rabies introduction has decreased 59 fold due to both the effective control of the issue of illegal landing of dogs and the decline in the number of Russian boat arrivals. Control efforts include education of Russian fishermen, establishment of warning signs, daily patrols and regular port surveillance of potential dog landing activity. Furthermore, scenario analysis revealed that the policy of mandatory domestic dog vaccination does not contribute effectively to Japan’s rabies prevention system under rabies-free situation. Although the current risk of rabies introduction is minimal, control measures against the illegal landing of dogs must be maintained. Further risk management measures, such as the removal of wildlife from the port area and regular monitoring of the rabies situation in Russia (particularly the easternmost regions), can be established to strengthen the current rabies prevention system in Hokkaido.

Reduced viral burden in paralytic compared to furious canine rabies is associated with prominent inflammation at the brainstem level

BackgroundThe mechanisms that differentiate rabies infections into furious and paralytic forms remain undetermined. There are no neuropathological features in human brains that distinguish furious and paralytic rabies. This could be due to methodology and/or examination of specimens late in the disease course.In this study, postmortem examination of brain (5 furious and 5 paralytic) and spinal cord (3 furious and 3 paralytic) specimens was performed in 10 rabies-infected dogs, sacrificed shortly after developing the illness. Rabies virus (RABV) antigen (percentage of positive neurons, average antigen area in positive neurons and average antigen area per neuron) and RNA were quantified at 15 different central nervous system (CNS) regions. The distribution and degree of inflammation were also studied.ResultsMore RABV antigen was detected in furious rabies than paralytic in many of the CNS regions studied. Caudal-rostral polarity of viral antigen distribution was found in both clinical forms in order from greatest to least: spinal cord, brainstem, cerebellum, midline structures (caudate, thalamus), hippocampus, and cerebrum. In contrast, RABV RNA was most abundant in the cerebral midline structures. Viral RNA was found at significantly higher levels in the cerebral cortex, thalamus, midbrain and medulla of dogs with the furious subtype. The RNA levels in the spinal cord were comparable in both clinical forms. A striking inflammatory response was found in paralytic rabies in the brainstem.ConclusionsThese observations provide preliminary evidence that RABV antigen and RNA levels are higher in the cerebrum in furious rabies compared to the paralytic form. In addition, brainstem inflammation, more pronounced in paralytic rabies, may impede viral propagation towards the cerebral hemispheres.

Analysis of the genetic differences in the nucleoprotein between rabies virus and its vaccine strains in Guizhou province from year 2005 to 2010

This study was to explore the differences in the nucleoprotein gene between rabies virus (RABV) and its vaccine strains in Guizhou province from year 2005 to 2010. Samples from 4 rabies patients and cerebral tissue samples of 28 rabies infected dogs were collected from different districts in Guizhou province between year 2005 and 2010. Direct Immunofluorescence Assay (DFA) and RT-nested PCR assay were applied to detect the overall length of N gene sequence. Meanwhile, based on the comparison between the homology and phylogenetic tree, the differences in N gene sequence between the prevalent RABV and the RABV vaccine strains collected from NCBI database in these years. According to DFA and RT-nested PCR assay, the antigen and nucleic acid of the 21 dogs and 4 human samples were both confirmed positive; whose full length of N gene sequences were both 1353 bp. The homological analysis showed that the 25 strains of RABV virus and the RABV type I virus stored by GenBank database shared a high homology in N gene nucleotide and amino acid sequences, which were 89%-100% and 98%-100%, respectively. Besides, the homology between the 25 strains of RABV virus and its vaccines in nucleotide and amino acid sequences were separately 86%-95% and 96%-100%. The N gene of vaccines for livestock shared the highest homology with HEP-Flury strain in the nucleotide and amino acid, which were 88%-89% and 98%-99%, respectively. The vaccines for human use showed its greatest homology with the CTN strain in nucleotide (86%-100%) and amino acid (96%-100%). The phylogenetic tree analysis indicated that the 25 strains of RABV virus, RABV type I virus and the CTN vaccine strains constituted one individual cluster, which was least different from the CTN vaccine for human use. The prevalent RABV virus, the vaccine HEP-Flury for livestock and the vaccine CTN for human use were found to be highly similar in N gene expression in Guizhou province from 2005 to 2010.

Levantamento e identificação dos aspectos epidemiológicos da raiva canina no município de Cuiabá - MT

Reconhecida desde a antiguidade, a raiva é uma infecção aguda do sistema nervoso central que acomete mamíferos, sendo causada por um RNA vírus da família Rabidoviridae, gênero Lyssavírus. O Brasil, desde a implantação do programa de controle da raiva em áreas urbanas, vem apresentando um declínio de casos de raiva em cães e em seres humanos. Em Cuiabá, as atividades realizadas pelo Centro de Controle de Zoonoses voltadas para o controle da raiva como: vacinação antirrábica animal, bloqueios de foco, captura de animais errantes, entre outros, permitiu o bloqueio da circulação do vírus na espécie canina. Desde 2008, o município de Cuiabá não registra nenhum caso da doença na espécie canina. Com o objetivo de conhecer a distribuição temporal da raiva canina em Cuiabá- MT, assim como identificar os aspectos epidemiológicos dos cães infectados pelo vírus rábico e verificar as medidas de profilaxia para a raiva canina, adotadas pelo Centro de Controle de Zoonose do município de Cuiabá no período de janeiro de 2002 a dezembro de 2008, realizou-se o presente estudo. Para o estudo observacional descritivo foi empregado o banco de dados referente à série histórica do CCZ e do Laboratório de Apoio a Saúde Animal - LASA ambos situados no município de Cuiabá- MT. O período de estudo foi de janeiro de 2002 a dezembro de 2008. Neste período foram examinadas 1021 amostras de cérebro de cães, destas 8,71% (89/1021) foram positivas e 91,29% (932/1021) negativas para a raiva. Os meses de maior incidência da doença foram os meses de janeiro 15,05% (14/93), fevereiro 12,5% (9/72), março 12,5% (9/72), abril 14,14% (9/72) e dezembro 13,69% (10/73). O maior número de cães doentes era macho 59,55% (53/89) com idade acima de dois anos 50,55% (45/89) e não domiciliados 67,41% (60/89). Em relação à imunoprofilaxia, a maioria dos cães 99,63% foi vacinada em campanhas. A cobertura vacinal ficou acima dos 80% exceto em 2006. Entre os animais que apresentaram a enfermidade o maior número, 67,41% (60/89), foi de cães não domiciliados, os chamados cães errantes. O percentual de cães domiciliados infectados pelos VR foi igual a 32,58% (29/89). As campanhas de vacinação, portanto, são fundamentais para a imunização do maior número de animais possível e a sociedade deve se conscientizar sobre a importância da raiva e as medidas que devem ser tomadas para controlá-la.

Comparative detection of rabies RNA by NASBA, real-time PCR and conventional PCR

Five methods for the RNA detection of rabies virus were directly compared in this study. These included conventional nucleic acid sequence-based amplification with electrochemiluminescence (NASBA-ECL) assay, reverse transcription (RT)-heminested (hn) polymerase chain reaction (PCR) and TaqMan real-time RT-PCR using protocols as described previously. The first two methods have been routinely utilised for ante-mortem diagnosis of human rabies in Thailand and other rabies-endemic Asian and African countries. In addition, two real-time NASBA assays based on the use of a NucliSens EasyQ analyser (NASBA-Beacon-EQ) and LightCycler real-time PCR machine (NASBA-Beacon-LC) were studied in parallel. All methods target the N gene, whereas the L gene is used for RT-hnPCR. Using serial dilutions of purified RNA from rabies-infected dog brain tissue to assess sensitivity, all five methods had comparable degrees of sensitivities of detection. However, both real-time NASBA assays had slightly lower sensitivities by 10-fold than the other three assays. This finding was also true (except for TaqMan real-time RT-PCR due to a mismatch between the target and probe sequences) when laboratory-adapted (challenge virus standard-11) virus was used in the assays. Testing on previously NASBA-ECL positive clinical samples from 10 rabies patients (saliva [6] and brain [4]) and 10 rabies-infected dog brain tissues, similar results were obtained among the five methods; real-time NASBA assays yielded false-negative results on 2 saliva samples. None of the assays showed positive results on cerebrospinal fluid specimens of 10 patients without rabies encephalitis. Due to the unavailability of the NASBA-ECL assay, the results show that TaqMan real-time RT-PCR and RT-hnPCR can be useful for ante- and post-mortem diagnosis of rabies.

Furious and paralytic rabies of canine origin: Neuroimaging with virological and cytokine studies

Furious and paralytic rabies differ in clinical manifestations and survival periods. The authors studied magnetic resonance imaging (MRI) and cytokine and virus distribution in rabies-infected dogs of both clinical types. MRI examination of the brain and upper spinal cord was performed in two furious and two paralytic dogs during the early clinical stage. Rabies viral nucleoprotein RNA and 18 cytokine mRNAs at 12 different brain regions were studied. Rabies viral RNA was examined in four furious and four paralytic dogs during the early stage, and in one each during the late stage. Cytokine mRNAs were examined in two furious and two paralytic dogs during the early stage and in one each during the late stage. Larger quantities of rabies viral RNA were found in the brains of furious than in paralytic dogs. Interleukin-1beta and interferon-gamma mRNAs were found exclusively in the brains of paralytic dogs during the early stage. Abnormal hypersignal T2 changes were found at hippocampus, hypothalamus, brainstem, and spinal cord of paralytic dogs. More widespread changes of less intensity were seen in furious dog brains. During the late stage of infection, brains from furious and paralytic rabid dogs were similarly infected and there were less detectable cytokine mRNAs. These results suggest that the early stage of furious dog rabies is characterized by a moderate inflammation (as indicated by MRI lesions and brain cytokine detection) and a severe virus neuroinvasiveness. Paralytic rabies is characterized by delayed viral neuroinvasion and a more intense inflammation than furious rabies. Dogs may be a good model for study of the host inflammatory responses that may modulate rabies virus neuroinvasiveness.

Mumps meningitis in south-east Scotland—a retrospective study

Five methods for the RNA detection of rabies virus were directly compared in this study. These included conventional nucleic acid sequence-based amplification with electrochemiluminescence (NASBA-ECL) assay, reverse transcription (RT)-heminested (hn) polymerase chain reaction (PCR) and TaqMan real-time RT-PCR using protocols as described previously. The first two methods have been routinely utilised for ante-mortem diagnosis of human rabies in Thailand and other rabies-endemic Asian and African countries. In addition, two real-time NASBA assays based on the use of a NucliSens EasyQ analyser (NASBA-Beacon-EQ) and LightCycler real-time PCR machine (NASBA-Beacon-LC) were studied in parallel. All methods target the N gene, whereas the L gene is used for RT-hnPCR. Using serial dilutions of purified RNA from rabies-infected dog brain tissue to assess sensitivity, all five methods had comparable degrees of sensitivities of detection. However, both real-time NASBA assays had slightly lower sensitivities by 10-fold than the other three assays. This finding was also true (except for TaqMan real-time RT-PCR due to a mismatch between the target and probe sequences) when laboratory-adapted (challenge virus standard-11) virus was used in the assays. Testing on previously NASBA-ECL positive clinical samples from 10 rabies patients (saliva [6] and brain [4]) and 10 rabies-infected dog brain tissues, similar results were obtained among the five methods; real-time NASBA assays yielded false-negative results on 2 saliva samples. None of the assays showed positive results on cerebrospinal fluid specimens of 10 patients without rabies encephalitis. Due to the unavailability of the NASBA-ECL assay, the results show that TaqMan real-time RT-PCR and RT-hnPCR can be useful for ante- and post-mortem diagnosis of rabies.

Purification of Rabies Antibodies in Horse Serum and Diagnostic Importance of the Fluorescent Antibody Technique

Summary Purified horse rabies antibody has been prepared by the isoelectric fractional alcohol precipitation method of Nichol and Deutsch, with a yield of 54%. Neutralizing antibody in the final preparation is found mainly in the γ-2-G fraction. Modifications of the method of Coons were used for conjugating the purified antirabies horse antibody with fluorescein isocyanate. Staining of brain smears from rabies-infected dogs and mice with fluorescent antibody showed the diagnostic usefulness of this method in a type of communicable disease in which prompt information is most urgent.