Antemortem diagnosis and prevention of human rabies

Molecular characterisation of human rabies in Tanzania and Kenya: a case series report and phylogenetic investigation

BACKGROUND

Rabies remains a major public health problem in low- and middle-income countries. However, human rabies deaths are rarely laboratory-confirmed or sequenced, especially in Africa. Five human rabies deaths from Tanzania and Kenya were investigated and the causative rabies viruses sequenced, with the aim of identifying implications for rabies control at individual, healthcare and societal levels.

CASE PRESENTATION

The epidemiological context and care of these cases was contrasting. Four had a clear history of being bitten by dogs, while one had an unclear biting history. Two individuals sought medical attention within a day of being bitten, whereas three sought care only after developing rabies symptoms. Despite seeking medical care, none of the cases received complete post-exposure prophylaxis: one patient received only tetanus vaccination, one did not complete the post-exposure vaccination regimen, one followed an off-label vaccination schedule, and two did not receive any post-exposure vaccinations before the onset of symptoms. These cases highlight serious gaps in health-seeking behaviour, and in health systems providing appropriate care following risky exposures, including in the accessibility and effectiveness of post-exposure prophylaxis as it is administered in the region.

CONCLUSIONS

The viral genomic and epidemiological data confirms dog-mediated rabies as the cause of each of these deaths. The phylogenetic investigation highlights the transboundary circulation of rabies within domestic dog populations, revealing distinct rabies virus clades with evidence of regional spread. These findings underscore the importance of coordinated cross-border control efforts between the two countries. Urgent action is needed to improve awareness around the need for emergency post-exposure vaccines that should be accessible in local communities and administered appropriately, as well as investment in coordinated dog vaccination to control dog-mediated rabies, the underlying cause of these deaths.

Magnetic resonance imaging in rabies encephalitis, a case report, and review of the literature

Rabies is an acute fatal disease of the central nervous system. Neuroimaging plays an important role, especially in establishing an early diagnosis and distinguishing it from other types of encephalitis. This case report aims to give a brief review of this condition and report the less common MRI findings of the disease. We herein report a case of a 61-year-old male bitten by a stray dog who presented with fever, vomiting, headache, sialorrhea, dysarthria, dysphagia, and upper limb weakness which progressed to lower limbs on the next day. T2W and FLAIR images demonstrated subtle bilateral hyperintense signal in the deep gray matter with more apparent increased signal intensity in the white matter of the frontal and parietal lobes which shows mild diffusion restriction but no postcontrast enhancement. The diagnosis of rabies encephalitis was made based on a typical history of exposure, a compatible clinical presentation, and MRI findings. Rabies diagnosis is essentially clinical. It is definitively confirmed by the isolation of the virus from biological samples such as saliva, CSF, hair, or detection of rabies antigens or antibodies. Magnetic resonance imaging (MRI) brain used as one of the modalities of investigation for distinguishing it from other encephalitis. Rabies per se does not have any characteristic features on the MRI brain.

[Rabies: Epidemiological update and pre- and post-exposure management]

Rabies is a deadly neurotropic viral infection but is preventable through vaccination. Its impact on human and animal health is often devastating. Despite advances in research and control of this disease, along with an effective vaccine, rabies continues to be a lingering threat in many parts of the world. Its high incidence reinforces the constant need to address it with scientific and public health measures. In this review article, we will explore the most important characteristics of the disease, its distribution, symptoms, prevention methods, and the global efforts that have been made to eradicate this deadly disease. The most recent research and advancements in the field of rabies will also be discussed in an effort to understand and combat this deadly disease more effectively.

Tracking lethal threat: in-depth review of rabies

An infectious disease known as rabies (family Rhabdoviridae, genus Lyssavirus) causes severe damage to mammals' central nervous systems (CNS). This illness has been around for a very long time. The majority of human cases of rabies take place in underdeveloped regions of Africa and Asia. Following viral transmission, the Rhabdovirus enters the peripheral nervous system and proceeds to the CNS, where it targets the encephalon and produces encephalomyelitis. Postbite prophylaxis requires laboratory confirmation of rabies in both people and animals. All warm-blooded animals can transmit the Lyssavirus infection, while the virus can also develop in the cells of cold-blooded animals. In the 21st century, more than 3 billion people are in danger of contracting the rabies virus in more than 100 different nations, resulting in an annual death toll of 50,000-59,000. There are three important elements in handling rabies disease in post exposure prophylaxis (PEP), namely wound care, administration of anti-rabies serum, and anti-rabies vaccine. Social costs include death, lost productivity as a result of early death, illness as a result of vaccination side effects, and the psychological toll that exposure to these deadly diseases has on people. Humans are most frequently exposed to canine rabies, especially youngsters and the poor, and there are few resources available to treat or prevent exposure, making prevention of human rabies challenging.

Case Report: Survival from Clinical Rabies in a Young Child from Maharashtra, India, 2022

A 3.5-year-old male child from Maharashtra, India, presented with features of meningoencephalitis approximately 1 month after sustaining severe bite injuries on the right hand from a stray dog. He had received four doses of post-exposure intradermal rabies vaccination (on days 0, 3, and 7 of the bite and erroneously on day 20, instead of day 28 as recommended in the updated Thai Red Cross regimen) as well as local and systemic injections of equine rabies immune globulin. The child was initially diagnosed with and treated for acute encephalitis syndrome before rabies encephalitis was confirmed by detection of rabies virus neutralizing antibodies in the cerebrospinal fluid. During the emergent period, he also received the antimalarial drug artesunate, recently reported to have antiviral effects against rabies virus. With intensive and supportive care, the child showed substantial clinical improvement over the next few weeks. He has now survived for more than 10 months after disease onset, albeit with severe neurological sequelae including diffuse cerebral and cerebellar atrophy.

Case report: Blood purification effectively relieves multiple system failure in patient with rabies

Rabies is an infectious disease of animal origin with a high mortality rate. In the early stages of rabies, the rabies virus (RABV) is usually undetectable in saliva and cerebrospinal fluid (CSF). In addition, there are still no effective drugs and treatments. Here, we present a case in which blood purification alleviated multisystem failures. The patient was a 45-year-old woman who presented with the fear of water and wind, restlessness, and hyperactivity. RABV was detected in her saliva by high-throughput sequencing Next Generation Sequencing (NGS) and polymerase chain reaction (PCR). Based on typical clinical symptoms and the result of NGS and PCR, the patient was diagnosed as a confirmed case of rabies. Hemodialysis combined with antiviral therapy and intensive care unit (ICU) treatment can effectively relieve circulatory failure, respiratory failure, and renal failure. Finally, she died of brain death on the 34th day of admission. The case report showed that blood purification was positive for rabies-induced organ failure. Blood purification combined with antiviral therapy can prolong the lives of patients with rabies to some extent.

Rabies in Europe: An epidemiological and clinical update

Rabies is a vaccine preventable zoonotic disease with a significant mortality burden worldwide. Several years of vaccination campaigns in wildlife animals have now achieved the control of rabies in Western Europe through a vaccination belt in front of endemic Eastern European countries. Nevertheless, rabies could be imported both by travellers from areas without an active public control of the disease or by animals coming from areas where the virus circulates in wildlife fauna. The knowledge of the current world epidemiology combined with a high index of clinical suspicion are needed to reach a diagnosis of rabies, especially in case of atypical presentation or without a history of animal exposure. The pre-travel counselling to people visiting highly endemic areas is essential to give information on how to reduce exposure to potential sources of infection and to select those subjects who could benefit from pre-travel vaccination. Rabies is almost invariably fatal, but the prompt administration of a vaccine course combined with anti-rabies immunoglobulins significantly reduces the probability to develop life-threatening consequences. In this review, we give a brief epidemiological and clinical update about rabies in Europe.

Altered mental status in "Guillain-Barré syndrome" -a noteworthy clinical clue

Guillain-Barré syndrome (GBS) is widely regarded as a "pure" peripheral nervous system disorder. However, this simplistic interpretation belies the fact that central nervous system involvement, often manifesting as derangements in mental status can occur as a complication of the "pure" form of the disorder, as part of GBS variants, as well as in a number of mimic disorders. Despite being common in clinical practice, there is no guidance in the literature as to how to approach such scenarios. Herein, we detail our approach to these cases.

Economic and feasibility comparison of the dRIT and DFA for decentralized rabies diagnosis in resource-limited settings: The use of Nigerian dog meat markets as a case study

BACKGROUND

Rabies lyssavirus (RABV) is the aetiologic agent of rabies, a disease that is severely underreported in Nigeria as well as elsewhere in Africa and Asia. Despite the role that rabies diagnosis plays towards elucidating the true burden of the disease, Nigeria-a country of 180 million inhabitants-has a limited number of diagnostic facilities. In this study, we sought to investigate two of the World Organization for Animal Health (OIE)-recommended diagnostic assays for rabies-viz; the direct fluorescent antibody test (DFA) and the direct rapid immunohistochemical test (dRIT) in terms of their relative suitability in resource-limited settings. Our primary considerations were (1) the financial feasibility for implementation and (2) the diagnostic efficacy. As a case study, we used suspect rabies samples from dog meat markets in Nigeria.

METHODS/PRINCIPAL FINDINGS

By developing a simple simulation framework, we suggested that the assay with the lowest cost to implement and routinely use was the dRIT assay. The costs associated with the dRIT were lower in all simulated scenarios, irrespective of the number of samples tested per year. In addition to the cost analysis, the diagnostic efficacies of the two assays were evaluated. To do this, a cohort of DFA-positive and -negative samples collected from dog meat markets in Nigeria were initially diagnosed using the DFA in Nigeria and subsequently sent to South Africa for diagnostic confirmation. In South Africa, all the specimens were re-tested with the DFA, the dRIT and a quantitative real-time polymerase chain reaction (qRT-PCR). In our investigation, discrepancies were observed between the three diagnostic assays; with the incongruent results being resolved by means of confirmatory testing using the heminested reverse transcription polymerase reaction and sequencing to confirm that they were not contamination.

CONCLUSIONS/SIGNIFICANCE

The data obtained from this study suggested that the dRIT was not only an effective diagnostic assay that could be used to routinely diagnose rabies, but that the assay was also the most cost-effective option among all of the OIE recommended methods. In addition, the results of our investigation confirmed that some of the dogs slaughtered in dog markets were rabies-positive and that the markets posed a potential public health threat. Lastly, our data showed that the DFA, although regarded as the gold standard test for rabies, has some limitations-particularly at low antigen levels. Based on the results reported here and the current challenges faced in Nigeria, we believe that the dRIT assay would be the most suitable laboratory test for decentralized or confirmatory rabies diagnosis in Nigeria, given its relative speed, accuracy, cost and ease of use.

Utility of rabies neutralizing antibody detection in cerebrospinal fluid and serum for ante-mortem diagnosis of human rabies

Background

Early ante-mortem laboratory confirmation of human rabies is essential to aid patient management and institute public health measures. Few studies have highlighted the diagnostic value of antibody detection in CSF/serum in rabies, and its utility is usually undermined owing to the late seroconversion and short survival in infected patients. This study was undertaken to examine the ante-mortem diagnostic utility and prognostic value of antibody detection by rapid fluorescent focus inhibition test (RFFIT) in cerebrospinal fluid (CSF)/serum samples received from clinically suspected human rabies cases from January 2015 to December 2017.

Methodology/Principal findings

Samples collected ante-mortem and post-mortem from 130 and 6 patients with clinically suspected rabies respectively, were received in the laboratory during the study period. Ante-mortem laboratory confirmation was achieved in 55/130 (42.3%) cases. Real time PCR for detection of viral nucleic acid performed on saliva, nuchal skin, brain tissue and CSF samples could confirm the diagnosis in 15 (27.2%) of the 55 laboratory confirmed cases. Ante-mortem diagnosis could be achieved by RFFIT (in CSF and/or serum) in 45 (34.6%) of the 130 clinically suspected cases, accounting for 81.8% of the total 55 laboratory confirmed cases. The sensitivity of CSF RFFIT increased with the day of sample collection (post-onset of symptoms) and was found to be 100% after 12 days of illness. Patients who had received prior vaccination had an increased probability of a positive RFFIT and negative PCR result. Patients who were positive by RFFIT alone at initial diagnosis had longer survival (albeit with neurological sequelae) than patients who were positive by PCR alone or both RFFIT and PCR.

Conclusions/Significance

Detection of antibodies in the CSF/serum is a valuable ante-mortem diagnostic tool in human rabies, especially in patients who survive beyond a week. It was also found to have a limited role as a prognostic marker to predict outcomes in patients.

Ante-mortem diagnosis of human rabies is essential for patient management and public health measures. The detection of virus specific antibodies in the CSF/serum of patients with suspected rabies is thought to have a limited diagnostic role owing to late seroconversion and short survival in rabies. We examined the diagnostic and prognostic utility of antibody detection by rapid fluorescent focus inhibition test (RFFIT) in CSF/serum samples received from clinically suspected human rabies cases (2015–2017). RFFIT (in CSF and/or serum) could confirm ante-mortem diagnosis in 45 (34.6%) of the 130 clinically suspected cases, accounting for 81.8% of the total 55 laboratory confirmed cases. The sensitivity of CSF RFFIT increased with the day of sample collection (post-onset of symptoms) and was found to be 100% after 12 days of illness. Patients who had received prior vaccination had an increased likelihood of a positive RFFIT and negative PCR result. Patients who were positive by RFFIT alone at initial diagnosis had longer duration of survival, although with poor functional outcomes. Antibody detection by RFFIT in CSF/serum was found to have a diagnostic utility especially in patients who survived beyond a week and a limited prognostic role in human rabies.

Case Reports: Survival from Rabies: Case Series from India

Rabies, a zoonotic viral encephalitis, continues to be a serious public health problem in India and several other countries in Asia and Africa. Survival is rarely reported in rabies, which is considered to be almost universally fatal. We report the clinical and radiological findings of eight patients with laboratory-confirmed rabies who survived the illness. With the exception of one patient who recovered with mild sequelae, all survivors had poor functional outcomes. The reported survival from rabies in recent years may reflect an increased awareness of the disease and greater access to better critical care facilities in rabies-endemic countries. Nonetheless, there is an urgent need to focus on preventive strategies to reduce the burden of this dreadful disease in rabies-endemic countries.

Community Awareness on Rabies Prevention and Control in Bicol, Philippines: Pre- and Post-Project Implementation

Rabies is endemic in the Philippines. To support the rabies campaign in the Bicol region at the southeastern part of Luzon, the BAI-OIE Stop Transboundary Animal Diseases and Zoonoses (STANDZ) Rabies project was implemented in the pilot provinces of Camarines Norte, Camarines Sur, Albay, and Masbate. A community awareness survey was conducted with the residents of these provinces to determine their knowledge, attitude, and practices (KAP) on rabies during the start and end of the project. Qualitative, descriptive research was done with a structured KAP questionnaire. Pet owners in the pilot provinces were chosen as respondents. Results showed that respondents know that they can acquire rabies in animals through the bite of a rabid dog (pre-project implementation (PRI): 19.6%, post-project implementation (POI): 38.0%). Vaccination was the top rabies preventive measure (PRI: 61.8%, POI: 92.8%). Biting incidents were noted in some respondents, and observing the dog and killing it immediately were some of the actions taken by bite victims. If a supposed rabid dog was seen, respondents would either: immediately kill the dog (PRI: 20.3%, POI: 13.7%), report it to authorities (PRI: 26.3%, POI: 63.1%), and capture and observe the dog concerned (PRI: 13.5%, POI: 6.0%). Pet owners increased their KAP about rabies prevention and control as compared to the pre-implementation study. However, certain gaps in their KAP need to be given attention; thus continuous education of pet owners must be done.

Rabies - epidemiology, pathogenesis, public health concerns and advances in diagnosis and control: a comprehensive review

Rabies is a zoonotic, fatal and progressive neurological infection caused by rabies virus of the genus Lyssavirus and family Rhabdoviridae. It affects all warm-blooded animals and the disease is prevalent throughout the world and endemic in many countries except in Islands like Australia and Antarctica. Over 60,000 peoples die every year due to rabies, while approximately 15 million people receive rabies post-exposure prophylaxis (PEP) annually. Bite of rabid animals and saliva of infected host are mainly responsible for transmission and wildlife like raccoons, skunks, bats and foxes are main reservoirs for rabies. The incubation period is highly variable from 2 weeks to 6 years (avg. 2-3 months). Though severe neurologic signs and fatal outcome, neuropathological lesions are relatively mild. Rabies virus exploits various mechanisms to evade the host immune responses. Being a major zoonosis, precise and rapid diagnosis is important for early treatment and effective prevention and control measures. Traditional rapid Seller's staining and histopathological methods are still in use for diagnosis of rabies. Direct immunofluoroscent test (dFAT) is gold standard test and most commonly recommended for diagnosis of rabies in fresh brain tissues of dogs by both OIE and WHO. Mouse inoculation test (MIT) and polymerase chain reaction (PCR) are superior and used for routine diagnosis. Vaccination with live attenuated or inactivated viruses, DNA and recombinant vaccines can be done in endemic areas. This review describes in detail about epidemiology, transmission, pathogenesis, advances in diagnosis, vaccination and therapeutic approaches along with appropriate prevention and control strategies.

A critical review on serine protease: Key immune manipulator and pathology mediator

Proteolytic activity is fundamental to survival, so it is not surprising that all living organisms have proteases, especially seine protease. This enzyme in its numerous isoforms and homologues, constitutes the quintessential offence and defence factors, in the form of surface proteins, secreted molecules, gut digestive enzymes, venom in specialised glands or plant latex, among other manifestations. Occurring as trypsin, chymotrypsin, elastase, collagenase, thrombin, subtilisin etc., it mediates a diverse array of functions, including pathological roles as inflammatory, coagulatory to haemorrhagic. This review emphasizes that despite the superficial differences in mechanisms, most health issues, be they infectious, allergic, metabolic, or neural have a common conduit. This enzyme, in its various glycosylated forms leads to signal misinterpretations, wreaking havoc. However, organisms are endowed with serine protease inhibitors which might restrain this ubiquitous yet deleterious enzyme. Hence, serine proteases-driven pathogenesis and antagonising role of inhibitors is the focal point of this critical review.

Every member of the kingdom Animalia is a potential vector of human pathogens

Zoonotic diseases are a subset of infectious diseases, which account for enormous morbidity and mortality. Pathologies like malaria, rabies, Lyme disease, leptospirosis, avian flu etc. are microbe- and parasite-caused ailments, where the etiological agents are introduced into or on the human body via ticks, mosquitoes, birds, rodents, bats, and deer, among other members of kingdom Animalia. While some of the zoonotic diseases are well-investigated and caution taken against, a lot many are yet to be recognized. This ignorance costs health, and lives, especially in developing countries. To promote awareness regarding the risks of immunogenicity and pathogen dissemination by hitherto unknown non-plant organisms, the members of kingdom Animalia, this letter has been compiled. The vector exploitation mechanisms of the pathogens, and in silico evidences of conserved protein domains across the potential pathogen reservoirs have been mentioned to underline the importance of this topic.

Pathway Analysis of Proteomics Profiles in Rabies Infection: Towards Future Biomarkers?

Rabies is a zoonotic viral disease that invariably leads to fatal encephalitis, which can be prevented provided post-exposure prophylaxis is initiated timely. Ante-mortem diagnostic tests are inconclusive, and rabies is nontreatable once the clinical signs appear. A large number of host factors are responsible for the altered neuronal functions observed in rabies; however their precise role remains uninvestigated. We therefore used two-dimensional electrophoresis and mass spectrometry analysis to identify differentially expressed host proteins in an experimental murine model of rabies. We identified 143 proteins corresponding to 45 differentially expressed spots (p < 0.05) in neuronal tissues of Swiss albino mice in response to infection with neurovirulent rabies strains. Time series analyses revealed that a majority of the alterations occur at 4 to 6 days post infection, in particular affecting the host's cytoskeletal architecture. Extensive pathway analysis and protein interaction studies using the bioinformatic tools such as Ingenuity Pathway Analysis and STRING revealed novel pathways and molecules (e.g., protein ubiquitination) unexplored hitherto. Further activation/inhibition studies of these pathway molecular leads would be relevant to identify novel biomarkers and mechanism-based therapeutics for rabies, a disease that continues to severely impact global health.

Perspectives in Diagnosis and Treatment of Rabies Viral Encephalitis: Insights from Pathogenesis

Rabies viral encephalitis, though one of the oldest recognized infectious disease of humans, remains an incurable, fatal encephalomyelitis, despite advances in understanding of its pathobiology. Advances in science have led us on the trail of the virus in the host, but the sanctuaries in which the virus remains hidden for its survival are unknown. Insights into host-pathogen interactions have facilitated evolving immunologic therapeutic strategies, though we are far from a cure. Most of the present-day knowledge has evolved from in vitro studies using fixed (attenuated) laboratory strains that may not be applicable in the clinical setting. Much remains to be unraveled about this elusive virus. This review attempts to re-examine the current advances in understanding of the pathobiology of the rabies virus that modulate the diagnosis, treatment, and prevention of this fatal disease.

Human rabies in India: an audit from a rabies diagnostic laboratory

OBJECTIVES

Rabies, an acute progressive encephalomyelitis, continues to be a serious public health problem in India and many other countries in Asia and Africa. The low level of commitment to rabies control is partly attributable to challenges in laboratory diagnosis and lack of adequate surveillance to indicate the disease burden. A laboratory audit of human rabies cases was undertaken to disseminate information on the clinical, demographic, prophylactic and most importantly the laboratory diagnostic aspects of rabies.

METHODS

A retrospective analysis of all clinically suspected human rabies cases, whose samples were received at a rabies diagnostic laboratory in South India in the last 3 years, was performed. Clinical and demographic details of patients were obtained. The clinical samples included cerebrospinal fluid (CSF), serum, saliva and nuchal skin biopsy collected antemortem, and brain tissue obtained post-mortem. Various laboratory tests were performed for diagnosis.

RESULTS

Clinical samples from 128 patients with suspected rabies, from 11 states in India, were received for diagnostic confirmation. About 94% of the victims reported dog-bites, more than a third of them were children and most of the victims did not receive adequate post-exposure prophylaxis. Antemortem confirmation of rabies by a combination of laboratory diagnostic assays (detection of viral RNA in CSF, skin and saliva, and neutralising antibodies in CSF) could be achieved in 40.6% cases.

CONCLUSIONS

Increasing awareness about adequate post-exposure prophylaxis, additional rabies diagnostic facilities, and enhanced human and animal rabies surveillance to indicate the true disease burden are essential to control this fatal disease.

RDIS: The Rabies Disease Information System

Rabies is a deadly viral disease causing acute inflammation or encephalitis of the brain in human beings and other mammals. Therefore, it is of interest to collect information related to the disease from several sources including known literature databases for further analysis and interpretation. Hence, we describe the development of a database called the Rabies Disease Information System (RDIS) for this purpose. The online database describes the etiology, epidemiology, pathogenesis and pathology of the disease using diagrammatic representations. It provides information on several carriers of the rabies viruses like dog, bat, fox and civet, and their distributions around the world. Information related to the urban and sylvatic cycles of transmission of the virus is also made available. The database also contains information related to available diagnostic methods and vaccines for human and other animals. This information is of use to medical, veterinary and paramedical practitioners, students, researchers, pet owners, animal lovers, livestock handlers, travelers and many others.

Human rabies: a descriptive observation of 21 children in Kinshasa, the Democratic Republic of Congo

OBJECTIVES

Human rabies has recently emerged as a significant public health threat in Kinshasa, Democratic Republic of Congo (DRC). However, there is little epidemiological information on human rabies especially in children.

METHODS

We performed at Pediatrics Department of General Reference hospital of Kinshasa between December 2008 and July 2009, a retrospective study to assess the incidence and to describe their clinical aspects and outcome.

RESULTS

A total of 21 cases were observed, rather three cases per month. There were 12 boys (57·1%) and 9 girls (42·9%). Biting animal was found to be dog in all cases (100%). The dog was not immunized in all of cases. On admission, all patients (100%) showed furious rabies manifestations. Only two (9·5%) had their wounds treated and received an anti-rabies vaccine (ARV) after the bite incident. Two (9·5%) patients received rabies immunoglobulin (RIG). The case-fatality rate was 100%.

CONCLUSIONS

The disease emerges as a new major public health problem because of a lack of knowledge regarding rabies risk, the poor management of dog bites. Preventative vaccination for rabies should be recommended in the population of Kinshasa, area at high risk to contract rabies, particularly in children.

Postgenomics biomarkers for rabies—the next decade of proteomics

Rabies is one of the oldest diseases known to mankind. The pathogenic mechanisms by which rabies virus infection leads to development of neurological disease and death are still poorly understood. Analysis of rabies-infected proteomes may help identify novel biomarkers for antemortem diagnosis of the disease and target molecules for therapeutic intervention. This article offers a literature synthesis and critique of the differentially expressed proteins that have been previously reported from various in vitro/in vivo model systems and naturally infected clinical specimens. The emerging data collectively indicate that, in addition to the obvious alterations in proteins involved in synapse and neurotransmission, a majority of cytoskeletal proteins are relevant as well, providing evidence of neuronal degeneration. An interesting observation is that certain molecules, such as KPNA4, could be potential diagnostic markers for rabies. Importantly, proteomic studies with body fluids such as cerebrospinal fluid provide newer insights into antemortem diagnosis. In order to develop a complete integrative biology picture, it is essential to analyze the entire CNS (region-wise) and in particular, the brain. We suggest the use of laboratory animal models over cell culture systems using a combinatorial proteomics approach, as the former is a closer match to the actual host response. While most studies have focused on the terminal stages of the disease in mice, a time-series analysis could provide deeper insights for therapy. Postgenomics technologies such as proteomics warrant more extensive applications in rabies and similar diseases impacting public health around the world.

Rabies post-exposure prophylaxis of overseas travelers in the international travel clinic of the national medical center from 2006 to 2012, Korea

Background

Rabies is an acute fatal viral disease generally transmitted from infected animals to humans through bites. It is distributed worldwide. The number of Korean people traveling to rabies-endemic countries and being bitten by infected animals has been increasing recently. Therefore, we investigated international travelers who received rabies post-exposure prophylaxis (PEP) at the National Medical Center (NMC) and compared the data with those of other clinics.

Materials and Methods

This study was a retrospective review of 106 patients who visited the International Travel Clinic of the NMC and received rabies PEP between July 2006 and December 2012. During that period, we used the Essen intramuscular regimen protocol. Complete rabies PEP was defined as 5 doses of rabies vaccination with or without rabies immunoglobulin (RIG) administration according to the World Health Organization guidelines.

Results

A total 106 cases documented within the period of 6 years were selected, including 10 children younger than 15 years and 96 older than 15 years. The mean age of the patients who received PEP was 33.4 years. Of the patients, 53 were male and another 53 were female. Most of the exposures occurred in Southeast Asia, predominantly from dog bites (71, 66.9%). The lower extremities were the most frequent site of exposure (37, 34.9%). All the patients began receiving rabies vaccination for prophylaxis after exposure, and 51 received rabies vaccination with RIG. Meanwhile, 74 cases (69.8%) initiated rabies vaccination overseas, but only 10 of them received RIG while overseas; the remaining 32 (30.2%) initiated rabies vaccination after returning to Korea. Within 7 days, all the children and 74 adults received their first rabies vaccination. Six adults initiated first rabies vaccination after 1 week. Eleven of the 106 patients stopped PEP before 5 doses, among whom 4 (1 child and 3 adults) discontinued vaccination after confirming that the biting animal remained healthy throughout 10 days of observation. None of the patients had been previously vaccinated against rabies.

Conclusions

Most of the overseas travelers who visited our clinic after being bitten by suspected rabid animals received appropriate rabies PEP. However, the interval between exposure and first rabies vaccination was often delayed. Tourists who plan to travel in rabies enzootic regions need to be aware that prompt initiation of PEP is important to reduce the risk for developing human rabies.

Survival from rabies encephalitis

Rabies is a major public health problem in Asia and Africa, with nearly 60,000 deaths every year, and represents a substantial economic burden. Neurologists frequently encounter atypical cases, and need to make informed decisions regarding diagnosis and management. No therapy has been shown to unequivocally improve survival in rabies till date. Despite the overwhelmingly fatal nature of this disease, a small number of patients have been reported to survive acute rabies encephalitis with varying degrees of neurological sequelae. This paper presents the eleventh documented case of survival from rabies, which developed after being bitten by a stray dog, albeit with severe neurological residua. Similar to patients in previous reports, this man demonstrated a robust immune response as indicated by peripheral viral clearance and very high serum and cerebrospinal fluid antibody titres. Immunologically-mediated virus clearance therefore appears to be a prerequisite for survival. A detailed review of previously reported survivors, as well as descriptions of the host response and viral clearance in human rabies, current therapy for this disease and future directions in improving the currently dismal prognosis are provided.

Rabies and dog bites cases in lagos state Nigeria: a prevalence and retrospective studies (2006-2011)

This study was carried out to determine the prevalence of rabies antigen in brain of dogs slaughtered for consumption and those that died in veterinary clinics as well as to obtain a 6-year retrospective data on dog bites/suspected dog rabies cases in Lagos State. Dog brain samples were collected from dog slaughter slabs and veterinary clinics (for dogs that died in clinics) across the Lagos state while data for retrospective studies (2006-2011) of dog bite/suspected rabies cases were collected from public (government owned) and private veterinary clinics across the state. Out of the 444 brain samples collected and tested for presence of rabies antigen using the direct fluorescent antibody technique (DFAT) only 7 (1.58%) were positive for the rabies antigen. A total of 196 dog bites/suspected rabies cases were encountered between January 2006 and December, 2011 in the veterinary clinics with adults been the major (55.61%) victims. Majority (96.43%) of the offending dogs were not quarantined at the time of bite and only one out of the quarantined dogs died and was confirmed positive for rabies antigen. The result of this study indicates that rabies antigen is present among dogs slaughtered in Lagos State and may pose a threat to public health. Though, available records showed that provocation of dogs was the major cause of dog bites and both children and adults fell victim of dog bites, there was a poor record keeping practice in the veterinary clinics across the state.

Utility of real-time Taqman PCR for antemortem and postmortem diagnosis of human rabies

Rabies, a fatal zoonotic viral encephalitis remains a neglected disease in India despite a high disease burden. Laboratory confirmation is essential, especially in patients with paralytic rabies who pose a diagnostic dilemma. However, conventional tests for diagnosis of rabies have several limitations. In the present study the utility of a real-time TaqMan PCR assay was evaluated for antemortem/postmortem diagnosis of rabies. Human clinical samples received for antemortem rabies diagnosis (CSF, saliva, nuchal skin biopsy, serum), and samples obtained postmortem from laboratory confirmed rabies in humans (brain tissue, CSF, serum) and animals (brain tissue) were included in the study. All CSF and sera were tested for rabies viral neutralizing antibodies (RVNA) by rapid fluorescent focus inhibition test (RFFIT) and all samples (except sera) were processed for detection of rabies viral RNA by real-time TaqMan PCR. All the 29 (100%) brain tissues from confirmed cases of human and animal rabies, and 11/14 (78.5%) CSF samples obtained postmortem from confirmed human rabies cases were positive by real-time TaqMan PCR. Rabies viral RNA was detected in 5/11 (45.4%) CSF samples, 6/10 (60%) nuchal skin biopsies, and 6/7 (85.7%) saliva samples received for antemortem diagnosis. Real-time TaqMan PCR alone could achieve antemortem rabies diagnosis in 11/13 (84.6%) cases; combined with RVNA detection in CSF antemortem rabies diagnosis could be achieved in all 13 (100%) cases. Real-time TaqMan PCR should be made available widely as an adjunctive test for diagnosis of human rabies in high disease burden countries like India.

Rabies encephalomyelitis vs. ADEM: Usefulness of MR imaging in differential diagnosis

We report a case of rabies encephalomyelitis in a 12-year-old boy who had received anti-rabies vaccine 6 weeks after being bitten by a puppy. The MR (magnetic resonance) imaging helped to differentiate rabies from acute disseminated encephalomyelitis (ADEM). ADEM involves the white matter predominantly, whereas rabies has a predilection for grey matter, that too of midline regions. This report emphasizes the usefulness of MRI in differentiating rabies and ADEM when encephalomyelitis occurs in a vaccinated child.

Epidemiology of central nervous system infection

In cases of central nervous system infection, it is crucial for the neuroradiologist to provide an accurate differential diagnosis of the possible pathogens involved so that treating physicians can be aided in the choice of empiric therapy. This approach requires the radiologist to be aware of local epidemiology and have knowledge of infectious agents that are endemic to their area of practice. This article reviews and discusses the changing epidemiology of pathogens most often observed in meningitis, brain abscess, epidural abscess, postoperative infections, and human immunodeficiency virus infection.

Epidemiological and clinical features of human rabies cases in Bali 2008-2010

BACKGROUND

Previously thought to be rabies free, Bali experienced an outbreak of animal and human rabies cases in November 2008. We describe the epidemiological and clinical data of human rabies cases occurring in the first two years of the outbreak.

METHODS

We analysed the patient records of all rabies cases from the Sanglah General Hospital in Denpasar, and district hospitals in Buleleng and Tabanan. A conventional reverse transcriptase polymerase chain reaction was developed to detect the rabies virus genome in saliva, corneal swabs, and ante- and post-mortem cerebrospinal fluid (CSF).

RESULTS

There were 104 human rabies cases in Bali during November 2008-November 2010. Patients' mean age was 36.6 years (range 3-84 years; SD 20.7), most were male (56.7%), and originated from rural districts. Almost all (92%) cases had a history of dog bite. Only 5.8% had their wounds treated and received an anti-rabies vaccine (ARV) after the bite incident. No patients received rabies immunoglobulin (RIG). The estimated time from dog bite to the onset of signs and symptoms was 110.4 days (range 12-720 days; SD 118.2). The mean length of medical care until death was 21.8 hours (range 1-220 hours; SD 32.6). Less than 50% of patients had prodromal symptoms. The most frequent prodromal symptom was pain or paraesthesia at the bite site (37.6%). The two most common central nervous system infection signs were agitation (89.2%) and confusion (83.3%). Signs of autonomic nervous system dysfunction included hydrophobia (93.1%), hypersalivation (88.2%), and dyspnea (74.4%). On admission, 22 of 102 patients (21.6%) showed paralytic manifestations, while the rest (78.4%) showed furious rabies manifestations. The case-fatality rate was 100%. The rabies virus genome was detected in 50 of 101 patients (49.5%) with the highest detection rate from post-mortem CSF samples.

CONCLUSIONS

Rabies is a major public health problem in Bali. Human fatalities occur because of a lack of knowledge regarding rabies risk, the poor management of dog bites, and the limited availability of RIG. Increasing public awareness of dog bite management, increasing the availability of ARV and RIG, and implementing an island-wide dog vaccination campaign will help prevent human rabies cases.

Detection of rabies virus nucleoprotein-RNA in several organs outside the Central Nervous System in naturally-infected vampire bats

Rabies is a neurological disease, but the rabies virus spread to several organs outside the central nervous system (CNS). The rabies virus antigen or RNA has been identified from the salivary glands, the lungs, the kidneys, the heart and the liver. This work aimed to identify the presence of the rabies virus in non-neuronal organs from naturally-infected vampire bats and to study the rabies virus in the salivary glands of healthy vampire bats. Out of the five bats that were positive for rabies in the CNS, by fluorescent antibody test (FAT), viral isolation in N2A cells and reverse transcription - polymerase chain reaction (RT-PCR), 100% (5/5) were positive for rabies in samples of the tongue and the heart, 80% (4/5) in the kidneys, 40% (2/5) in samples of the salivary glands and the lungs, and 20% (1/5) in the liver by RT-PCR test. All the nine bats that were negative for rabies in the CNS, by FAT, viral isolation and RT-PCR were negative for rabies in the salivary glands by RT-PCR test. Possible consequences for rabies epidemiology and pathogenesis are discussed in this work.