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).

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.

Paralytic rabies: MRI findings and review of literature.

Paralytic rabies closely simulates Guillain-Barre syndrome or ascending myelitis often causing clinical dilemma. Two such patients were managed in our hospital whose magnetic resonance imaging (MRI) revealed characteristic findings revealing T2 hyper intensity in central spinal cord and in posterior brainstem and hypothalamus. These MRI findings are helpful in the diagnosis of rabies in appropriate setting. We also review the literature on MRI changes in paralytic rabies.

Coronary artery dilatation and vasculitis in a case of rabies: similarity with Kawasaki disease?

A 9-year-old boy died of rabies complications. We report the unusual combination between rabies, coronary dilatation on echocardiography and coronary vasculitis documented upon autopsy. In the search for the etiological agent of Kawasaki disease, we suggest that a viral infection with potential antigenic similarities to rabies virus should be entertained.

Recovery of a patient from clinical rabies--California, 2011.

In May 2011, a girl aged 8 years from a rural county in California was brought to a local emergency department (ED) with a 1-week history of progressive sore throat, difficulty swallowing, and weakness. After she developed flaccid paralysis and encephalitis, rabies was diagnosed based on 1) detection of rabies virus-specific antibodies in serum and cerebrospinal fluid (CSF), 2) a compatible clinical syndrome in the patient, and 3) absence of a likely alternative diagnosis. The patient received advanced supportive care, including treatment with therapeutic coma. She was successfully extubated after 15 days and discharged from the hospital 37 days later to continue rehabilitation therapy as an outpatient. The public health investigation identified contact with free-roaming, unvaccinated cats at the patient's school as a possible source of infection. Several of these cats were collected from the school and remained healthy while under observation, but at least one was lost to follow-up. A total of 27 persons received rabies postexposure prophylaxis (PEP) for potential exposures to the patient's saliva. No further cases of rabies associated with this case have been identified. Rabies prevention efforts should highlight the importance of domestic animal vaccination, avoidance of wildlife and unvaccinated animals, and prompt PEP after an exposure.

Imported human rabies -New Jersey, 2011.

On July 8, 2011, the New Jersey Department of Health and Senior Services (NJDHSS) contacted CDC about possible rabies in a hospitalized Haitian woman aged 73 years. Rabies was included in the differential diagnosis because she had acute, progressive encephalitis of unknown etiology. No history of animal exposure had been reported at the time of hospitalization. On July 18, CDC confirmed rabies virus infection, later identified as a canine rabies virus variant present in Haiti. The patient's neurologic status continued to deteriorate, leading to her death on July 20. This report summarizes the patient's clinical course and the associated public health investigation. This is the third report of human rabies in the United States acquired in Haiti since 2000 and highlights the importance of obtaining a detailed history for patients who have traveled from a rabies-endemic country and the value of consultation with medical and public health professionals regarding any animal bites.

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.

Human rabies from exposure to a vampire bat in Mexico --- Louisiana, 2010.

In August 2010, CDC confirmed a case of rabies in a migrant farm worker, aged 19 years, hospitalized in Louisiana with encephalitis. The man developed acute neurologic symptoms at the end of July, shortly after arriving in the United States from Michoacán, Mexico. Despite supportive care, his condition deteriorated, and he died on August 21. Antemortem diagnostic testing confirmed the diagnosis of rabies, and samples collected at autopsy were positive for a vampire bat rabies virus variant. The patient's mother reported that he had been bitten by a bat in July in Mexico but had not sought medical care. Postexposure prophylaxis (PEP) was offered to 27 of the patient's contacts in Louisiana and to 68 health-care workers involved in his care. Although bats have become the primary source of human rabies in the United States, this is the first reported death from a vampire bat rabies virus variant in the United States. Clinicians caring for patients with acute progressive encephalitis should consider rabies in the differential diagnosis and implement early infection control measures.

Human rabies--Wisconsin, 2010.

In late December 2010, a male resident of Wisconsin, aged 70 years, sought treatment for progressive right shoulder pain, tremors, abnormal behavior, and dysphagia at an emergency department (ED). He was admitted for observation and treated with benzodiazepines and haloperidol, a neuroleptic, for presumed alcohol withdrawal syndrome. The next day, he had rhabdomyolysis, fever, and rigidity, and neuroleptic malignant syndrome was diagnosed. The neuroleptic was discontinued, but the patient's clinical status worsened, with encephalopathy, respiratory failure, acute renal failure requiring hemodialysis, and episodes of cardiac arrest. With continued clinical deterioration, additional causes were considered, including rabies. On hospital day 12, rabies virus antigens and nucleic acid were detected in the nuchal skin biopsy and rabies virus nucleic acid in saliva specimens sent to CDC. A rabies virus variant associated with silver-haired bats (Lasionycteris noctivagans) was identified. The patient died on hospital day 13. His spouse reported that they had been selling firewood, and bats had been present in the woodpile; however, the man had not reported a bat bite. Two relatives and five health-care workers potentially exposed to the man's saliva received postexposure prophylaxis. This case highlights the variable presentations of rabies and the ease with which a diagnosis of rabies can be missed in a clinically challenging patient with comorbidities. Clinicians should consider rabies in the differential diagnosis for patients with progressive encephalitis or neurologic illness of unknown etiology and caregivers should take precautions to avoid exposure to body fluids. Continued public education regarding risks for rabies virus exposure during interactions with wildlife, particularly bats, is important.

Human rabies--Michigan, 2009.

On November 9, 2009, a Michigan hospital informed CDC of suspected rabies in a man aged 55 years. The patient reportedly had awakened with a bat on his arm 9 months earlier but had not sought medical evaluation. He went to a local emergency department (ED) on October 30 and soon after was hospitalized; he died 12 days later. On November 14, CDC confirmed infection with a rabies virus variant that commonly infects the silver-haired bat (Lasionycteris noctivagans). This report summarizes the patient's clinical course and the associated public health investigation. The report highlights the importance of public awareness of rabies, particularly among persons who might be at risk for wildlife exposures. Persons who experience contact with a bat and cannot confidently rule out a bite or scratch should seek prompt medical attention.

Suppression of cell-mediated immunity by street rabies virus.

Mice lethally infected with street rabies virus failed to develop cytotoxic T cells specific for rabies virus-infected target cells, whereas high levels of cell-mediated cytotoxicity (CMC) were generated after nonfatal infection with the attenuated high egg passage (HEP) or ERA rabies virus strains. Furthermore concurrent infection with street, but not with HEP, rabies virus suppresses development of a primary (but not a secondary) CMC response specific for influenza virus. No cross-reactivity is found between effector T-cell populations from mice immunized with HEP or with influenza virus. It thus appears that street rabies virus, which is not known to replicate in the cells of immune system, induces some general defect in the primary CMC lymphocyte response, though restimulation of memory T-cell populations is unimpaired and there is no defect in antibody formation. Development of fatal rabies may reflect the operation of this selective immunosuppressive mechanism.

Rabies viral encephalitis: clinical determinants in diagnosis with special reference to paralytic form.

BACKGROUND: Rabies is an important public health problem in developing countries such as India where an alarmingly high incidence of the infection is reported every year despite the availability of highly effective, potent and safe vaccines. In clinical practice, diagnosis of the furious (encephalitic) form of rabies poses little difficulty. In contrast, the paralytic form poses a diagnostic dilemma, to distinguish it from Guillain-Barré syndrome. The problem is further compounded in the absence of a history of dog bite, clinical features resembling a psychiatric syndrome. METHOD: The present study analysed the spectrum of neurological manifestations in 47 cases of rabies encephalitis (34 paralytic, six encephalitic, and seven psychiatric manifestations) from two hospitals in south India, confirmed at post-mortem by demonstration of a viral antigen in the brain. A history of dog bite was elicited in 33 patients and fox bite in one. Twenty-two patients received postexposure prophylaxis. The incubation period ranged from 7 days to 4 years. Clinical features were analysed, looking for any clinical pointers that provide clues to a diagnosis of paralytic rabies. RESULTS AND DISCUSSION: Fever, distal paresthaesias, fasciculation, alteration in sensorium, rapid progression of symptoms and pleocytosis in cerebrospinal fluid should alert the neurologist to consider rabies encephalomyelitis. Detection of the viral antigen in the corneal smear and a skin biopsy from the nape of the neck had limited usefulness in the ante-mortem diagnosis. Although a few clinical signs may help indicate rabies encephalomyelitis antemortem, confirmation requires neuropathological/neurovirological assistance. The preponderance of atypical/paralytic cases in this series suggests that neurologists and psychiatrists need to have a high index of clinical suspicion, particularly in the absence of a history of dog bite.

Presumptive abortive human rabies - Texas, 2009.

Rabies is a serious zoonotic disease. Recovery has been well documented in only six human patients worldwide. Five of those patients had received rabies vaccinations before illness; one had not received rabies vaccination but survived infection after prolonged intensive care. In most of these survivors, moderate to profound neurologic sequelae occurred. In all six survivors, rabies was diagnosed based on exposure history, compatible clinical symptoms, and detection of rabies virus-neutralizing antibodies (VNA). This report describes the clinical course and laboratory findings of an adolescent girl with encephalitis who had not had rabies vaccination and who had been exposed to bats 2 months before illness. Antibodies to rabies virus were detected in specimens of the girl's serum and cerebrospinal fluid (CSF) by indirect fluorescent antibody test (IFA). However, the presence of rabies VNA was not detected until after she had received single doses of rabies vaccine and human rabies immune globulin (HRIG). Although the patient required multiple hospitalizations and follow-up visits for recurrent neurologic symptoms, she survived without intensive care. No alternate etiology was determined, and abortive human rabies (defined in this report as recovery from rabies without intensive care) was diagnosed. Public education should emphasize avoiding exposure to bats and other potentially rabid wildlife and seeking prompt medical attention after exposure to such animals. Rabies is preventable if rabies immune globulin and vaccine are administered soon after an exposure; however, this case also suggests the rare possibility that abortive rabies can occur in humans and might go unrecognized.

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.