A spatial and cellular distribution of rabies virus infection in the mouse brain revealed by fMOST and single-cell RNA sequencing.

BACKGROUND: Neurotropic virus infection can cause serious damage to the central nervous system (CNS) in both humans and animals. The complexity of the CNS poses unique challenges to investigate the infection of these viruses in the brain using traditional techniques. METHODS: In this study, we explore the use of fluorescence micro-optical sectioning tomography (fMOST) and single-cell RNA sequencing (scRNA-seq) to map the spatial and cellular distribution of a representative neurotropic virus, rabies virus (RABV), in the whole brain. Mice were inoculated with a lethal dose of a recombinant RABV encoding enhanced green fluorescent protein (EGFP) under different infection routes, and a three-dimensional (3D) view of RABV distribution in the whole mouse brain was obtained using fMOST. Meanwhile, we pinpointed the cellular distribution of RABV by utilizing scRNA-seq. RESULTS: Our fMOST data provided the 3D view of a neurotropic virus in the whole mouse brain, which indicated that the spatial distribution of RABV in the brain was influenced by the infection route. Interestingly, we provided evidence that RABV could infect multiple nuclei related to fear independent of different infection routes. More surprisingly, our scRNA-seq data revealed that besides neurons RABV could infect macrophages and the infiltrating macrophages played at least three different antiviral roles during RABV infection. CONCLUSION: This study draws a comprehensively spatial and cellular map of typical neurotropic virus infection in the mouse brain, providing a novel and insightful strategy to investigate the pathogenesis of RABV and other neurotropic viruses.

Enigma of Rabies: Prolonged Survival in a Boy with Rabies Brachial Plexitis and Encephalomyelitis.

Rabies encephalitis is a universally fatal disease. Prolonged survival in children with rabies encephalitis has only been anecdotally reported. Case report: An 11-year-old boy presented with right-handed paraesthesia followed by flaccid weakness, progressive quadriparesis and encephalopathy following an unprovoked, class III dog bite over the right wrist 1 month previously. He received five doses of the rabies vaccine as post exposure prophylaxis. Diagnosis of rabies encephalitis was supported by typical MRI brain and spine findings in addition to marked elevation of anti-rabies neutralizing antibody titers in serum and CSF. He was treated with supportive care, methylprednisolone, dexamethasone and simvastatin and was discharged after 6 weeks of hospital stay in a minimally conscious state, with tracheostomy and naso-gastric feeding tubes. At 9 months follow-up, his neurological status showed minimal improvement. Paralytic rabies with brachial plexitis and encephalomyelitis is an atypical presentation of rabies. Very few surviving cases have been reported from India. Survival from rabies is possible with effective clearing of virus with post exposure prophylaxis, but with severe neurological sequelae.

Rabies encephalitis and extra-neural manifestations in a patient bitten by a domestic cat.

Rabies encephalitis is a fatal zoonotic viral disease transmitted to humans either by domestic animals like dogs and cats or by wild animals like bats, skunks and raccoons. We present the case of a 25-year-old woman admitted due to behavioral disorders, generalized paresthesiasand acute respiratory deterioration compatible with a respiratory distress syndrome (ARDS) requiring orotracheal intubation, mechanical ventilation and empirical initiation of antibiotic and antiviral therapy. Chest tomography showed pneumomediastinum and changes suggestive of pulmonary infection. In the presence of neurological symptoms, a central nervous system (CNS) infection was suspected and the cerebrospinal fluid showed no pleocytosis, hiperproteinorrachy without glucose consumption; cranial CT scan was normal. During hospitalization, the family reported that the patient was bitten by a cat 30-day prior to the onset of rabies-like symptoms, and the animal was sacrificed. The patient had an unfavorable clinical evolution, with electroencephalographic activity dissociation evidenced by video telemetry. The zoonotic exposure led to the suspected diagnosis of rabies infection. The patient died and the suspected diagnosis was confirmed by histopathology, with presence of Negri bodies on cerebellum Purkinje cells and a positive immunofluorescence test for rabies virus. Both, initial extra-neural manifestations and late reporting of rabies exposure led to delayed diagnosis.

Paralytic rabies in a goat.

BACKGROUND: Paralytic form of rabies is frequent in cattle in Latin America, but it is uncommon in goats. There are few clinical reports on furious rabies affecting goats, and the sporadic cases of rabid goats from surveillance programs worldwide lack clinical data. Furthermore, few studies reported the cerebrospinal fluid findings in rabid livestock. CASE PRESENTATION: On a farm in Midwestern Brazil, six of 47 Saanen goats died within one week. No vaccination protocols were implemented on the farm and the owner stated bat bites history on the livestock. Although rabies is endemic in Brazil, livestock vaccination is not mandatory. One 1-year-old buck was evaluated and showed non-specific clinical signs evolving within 12-h to nervous signs. Cerebrospinal fluid analysis revealed mononuclear pleocytosis, hyperproteinemia and high glucose levels. At necropsy, no gross lesions were present. Microscopically, discrete to moderate perivascular lymphoplasmacytic cuffing in gray and white matter, neuronal necrosis, neuronophagia, and mononuclear ganglioneuritis was observed in the brainstem and cervical spinal cord. Immunohistochemistry revealed strong anti-rabies virus immunostaining. Fresh central nervous system samples were positive for rabies in direct fluorescent antibody test (dFAT) and mouse intracerebral inoculation test (MIT). Exposed livestock recommendations included immediate vaccination, a strict isolation period of 90 days, and booster vaccinations during the third and eighth weeks. CONCLUSION: IHC revealed the widespread distribution of rabies virus antigen in the goat's CNS, contrasting the discrete pathological changes. In this goat, definitive diagnosis of paralytic rabies was obtained through the association of epidemiological, clinical, laboratorial, pathological findings (histology and IHC) and gold standard confirmatory tests (dFAT and MIT).

Frequency of Virus Coinfection in Raccoons ( Procyon lotor) and Striped Skunks ( Mephitis mephitis) During a Concurrent Rabies and Canine Distemper Outbreak.

Rabies and canine distemper virus infections in wildlife share similar presenting signs. Canine distemper virus was detected using real-time PCR of conjunctival swabs in rabies positive raccoons (22/32) and skunks (7/34) during a concurrent rabies and canine distemper outbreak in Ontario, Canada in 2015-16. Coinfections with both viruses should be considered, particularly in distemper endemic areas that are at risk of rabies incursion.

Rabies.

Rabies is a life-threatening neglected tropical disease: tens of thousands of cases are reported annually in endemic countries (mainly in Africa and Asia), although the actual numbers are most likely underestimated. Rabies is a zoonotic disease that is caused by infection with viruses of the Lyssavirus genus, which are transmitted via the saliva of an infected animal. Dogs are the most important reservoir for rabies viruses, and dog bites account for >99% of human cases. The virus first infects peripheral motor neurons, and symptoms occur after the virus reaches the central nervous system. Once clinical disease develops, it is almost certainly fatal. Primary prevention involves dog vaccination campaigns to reduce the virus reservoir. If exposure occurs, timely post-exposure prophylaxis can prevent the progression to clinical disease and involves appropriate wound care, the administration of rabies immunoglobulin and vaccination. A multifaceted approach for human rabies eradication that involves government support, disease awareness, vaccination of at-risk human populations and, most importantly, dog rabies control is necessary to achieve the WHO goal of reducing the number of cases of dog-mediated human rabies to zero by 2030.

Rabies virus vaccine as an immune adjuvant against cancers and glioblastoma: new studies may resurrect a neglected potential.

To review the literature about the use of Rabies Virus-Vaccine (RV-V) as an anticancer immunotherapeutic modality in the light of recent findings. The literature search in relevant databases with the following key words: Rabies virus, cancer, remission. Remissions occured following RV-V injections in patients with cervical cancer and melanoma. Pilot clinical studies showed that RV-V injections enhanced survival in glioblastoma patients, which is supported by findings in GL261 mouse glioma model. If public health studies demonstrate protective role of RV-V against certain types of cancers, it can be benefitted as a novel immune adjuvant in clinic.

Rapidly Progressive Quadriplegia and Encephalopathy.

A woman aged 77 years was transferred to our neurocritical care unit for evaluation and treatment of rapidly progressive motor weakness and encephalopathy. Examination revealed an ability to follow simple commands only and abnormal movements, including myoclonus, tongue and orofacial dyskinesias, and opsoclonus. Imaging study findings were initially unremarkable, but when repeated, they demonstrated enhancement of the cauda equina nerve roots, trigeminal nerve, and pachymeninges. Cerebrospinal fluid examination revealed mildly elevated white blood cell count and protein levels. Serial electrodiagnostic testing demonstrated a rapidly progressive diffuse sensory motor axonopathy, and electroencephalogram findings progressed from generalized slowing to bilateral periodic lateralized epileptiform discharges. Critical details of her recent history prompted a diagnostic biopsy. Over time, the patient became completely unresponsive with no further abnormal movements and ultimately died. The differential diagnosis, pathological findings, and diagnosis are discussed with a brief review of a well-known yet rare diagnosis.

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.

Caring for patients with rabies in developing countries - the neglected importance of palliative care.

Although limited publications address clinical management of symptomatic patients with rabies in intensive care units, the overwhelming majority of human rabies cases occur in the rural setting of developing countries where healthcare workers are few, lack training and drugs. Based on our experience, we suggest how clinicians in resource-limited settings can make best use of essential drugs to provide assistance to patients with rabies and their families, at no risk to themselves. Comprehensive and compassionate patient management of furious rabies should aim to alleviate thirst, anxiety and epileptic fits using infusions, diazepam or midazolam and antipyretic drugs via intravenous or intrarectal routes. Although the patient is dying, respiratory failure must be avoided especially if the family, after being informed, wish to take the patient home alive for funereal rites to be observed. Healthcare staff should be trained and clinical guidelines should be updated to include palliative care for rabies in endemic countries.

Critical Appraisal of the Milwaukee Protocol for Rabies: This Failed Approach Should Be Abandoned.

The Milwaukee protocol has been attributed to survival in rabies encephalitis despite a lack of scientific evidence supporting its therapeutic measures. We have reviewed the literature with reference to specific treatment recommendations made within the protocol. Current literature fails to support an important role for excitotoxicity and cerebral vasospasm in rabies encephalitis. Therapies suggested in the Milwaukee protocol include therapeutic coma, ketamine infusion, amantadine, and the screening/prophylaxis/management of cerebral vasospasm. None of these therapies can be substantiated in rabies or other forms of acute viral encephalitis. Serious concerns over the current protocol recommendations are warranted. The recommendations made by the Milwaukee protocol warrant serious reconsideration before any future use of this failed protocol.

Severe ketoalkalosis as initial presentation of imported human rabies in France.

We report a patient with an unusual initial metabolic presentation of imported human rabies who became symptomatic within 2 weeks of returning from Mali to France. This is the single case of imported human rabies identified in France within the past 11 years and the first report of viral RNA in bronchial secretions.

Neurogenic cardiomyopathy in rabbits with experimentally induced rabies.

Cardiomyopathies have been rarely described in rabbits. Here we report myocardial necrosis of the ventricular wall in rabbits with experimentally induced rabies. Myocardial lesions were found only in rabbits with brain lesions, and the severity of the cardiac lesions was proportional to that of the brain lesions. Neither the frequency nor the cumulative dose of anesthesia was related to the incidence or the severity of the myocardial lesions. The myocardial lesions were characterized by degeneration and/or necrosis of myocardial cells and were accompanied by contraction band necrosis, interstitial fibrosis, and infiltration of inflammatory cells. The brain lesions due to rabies virus infection were most prominent in the cerebral cortex, thalamus, hypothalamus, brainstem, and medulla. Rabies virus antigen was not found in the hearts of any rabbits. Based on these findings, the myocardial lesions were classified as neurogenic cardiomyopathy.

Interspecific aggression by a rabid eastern red bat (Lasiurus borealis).

On 16 March 2012 a rabid eastern red bat (Lasiurus borealis) was found attached to an evening bat (Nycticeius humeralis) in Randolph County, Arkansas, USA. This appears to be the first confirmed case of a rabid bat attacking a bat of another species.

Rabies, tetanus, leprosy, and malaria.

The developing world is still endemic to rabies, tetanus, leprosy, and malaria. Globally more than 55000 people die of rabies each year, about 95% in Asia and Africa. Annually, more than 10 million people, mostly in Asia, receive postexposure vaccination against the disease. World Health Organization estimated tetanus-related deaths at 163000 in 2004 worldwide. Globally, the annual detection of new cases of leprosy continues to decline and the global case detection declined by 3.54% during 2008 compared to 2007. Malaria is endemic in most countries, except the US, Canada, Europe, and Russia. Malaria accounts for 1.5-2.7 million deaths annually. Much of the disease burden related to these four infections is preventable.

Psychotic disorder after contact with a potentially rabid animal and post-exposure prophylactic anti-rabies treatment.

We present the case of a 19-year-old who developed psychotic symptoms after exposure to a potentially rabid animal and post-exposure prophylactic treatment. This case serves to remind physicians to fully explore the possibility of a nonpsychiatric origin of de novo psychotic symptoms and provides indirect evidence in favor of the possible involvement of the immune system in the development of psychotic disorders.