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Epstein JH, Anthony SJ, Islam A, Kilpatrick AM, Ali Khan S, Balkey MD, Ross N, Smith I, Zambrana-Torrelio C, Tao Y, Islam A, Quan PL, Olival KJ, Khan MSU, Gurley ES, Hossein MJ, Field HE, Fielder MD, Briese T, Rahman M, Broder CC, Crameri G, Wang LF, Luby SP, Lipkin WI, Daszak P. Nipah virus dynamics in bats and implications for spillover to humans. Proc Natl Acad Sci U S A 2020; 117:29190-29201. [PMID: 33139552 PMCID: PMC7682340 DOI: 10.1073/pnas.2000429117] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Nipah virus (NiV) is an emerging bat-borne zoonotic virus that causes near-annual outbreaks of fatal encephalitis in South Asia-one of the most populous regions on Earth. In Bangladesh, infection occurs when people drink date-palm sap contaminated with bat excreta. Outbreaks are sporadic, and the influence of viral dynamics in bats on their temporal and spatial distribution is poorly understood. We analyzed data on host ecology, molecular epidemiology, serological dynamics, and viral genetics to characterize spatiotemporal patterns of NiV dynamics in its wildlife reservoir, Pteropus medius bats, in Bangladesh. We found that NiV transmission occurred throughout the country and throughout the year. Model results indicated that local transmission dynamics were modulated by density-dependent transmission, acquired immunity that is lost over time, and recrudescence. Increased transmission followed multiyear periods of declining seroprevalence due to bat-population turnover and individual loss of humoral immunity. Individual bats had smaller host ranges than other Pteropus species (spp.), although movement data and the discovery of a Malaysia-clade NiV strain in eastern Bangladesh suggest connectivity with bats east of Bangladesh. These data suggest that discrete multiannual local epizootics in bat populations contribute to the sporadic nature of NiV outbreaks in South Asia. At the same time, the broad spatial and temporal extent of NiV transmission, including the recent outbreak in Kerala, India, highlights the continued risk of spillover to humans wherever they may interact with pteropid bats and the importance of limiting opportunities for spillover throughout Pteropus's range.
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Affiliation(s)
| | - Simon J Anthony
- Center for Infection and Immunity, Columbia University, New York, NY 10032
| | | | - A Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
| | - Shahneaz Ali Khan
- EcoHealth Alliance, New York, NY 10018
- Chattogram Veterinary and Animal Sciences University, Chattogram, Khulshi 4225, Bangladesh
| | - Maria D Balkey
- Center for Infection and Immunity, Columbia University, New York, NY 10032
- Center for Food Safety & Applied Nutrition, U.S. Food & Drug Administration, College Park, MD 20740
| | - Noam Ross
- EcoHealth Alliance, New York, NY 10018
| | - Ina Smith
- CSIRO Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation, Geelong, VIC 3219, Australia
| | | | - Yun Tao
- EcoHealth Alliance, New York, NY 10018
| | - Ausraful Islam
- International Centre for Diarrhoeal Diseases Research, Bangladesh, Dhaka 1212, Bangladesh
| | - Phenix Lan Quan
- Center for Infection and Immunity, Columbia University, New York, NY 10032
| | | | - M Salah Uddin Khan
- International Centre for Diarrhoeal Diseases Research, Bangladesh, Dhaka 1212, Bangladesh
| | - Emily S Gurley
- International Centre for Diarrhoeal Diseases Research, Bangladesh, Dhaka 1212, Bangladesh
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205
| | - M Jahangir Hossein
- Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | | | - Mark D Fielder
- School of Life Sciences, Science, Engineering and Computing Faculty, Kingston University, London KT1 2EE, United Kingdom
| | - Thomas Briese
- Center for Infection and Immunity, Columbia University, New York, NY 10032
| | - Mahmudur Rahman
- Institute of Epidemiology, Disease Control, and Research, Government of Bangladesh, Dhaka 1212, Bangladesh
| | - Christopher C Broder
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814
| | - Gary Crameri
- CSIRO Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation, Geelong, VIC 3219, Australia
| | - Lin-Fa Wang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857
| | - Stephen P Luby
- International Centre for Diarrhoeal Diseases Research, Bangladesh, Dhaka 1212, Bangladesh
- Department of Infectious Diseases & Geographic Medicine, Stanford University, Stanford, CA 94305
| | - W Ian Lipkin
- Center for Infection and Immunity, Columbia University, New York, NY 10032
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2
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Kadochnikov DS, Polianskiĭ DA, Minaeva PV. [The peculiarities of the evaluation of the severity of the harm to health in the case of development of psychic problems associated with the concomitant HIV infection and the accompanying infectious pathology]. Sud Med Ekspert 2016; 59:7-12. [PMID: 27030090 DOI: 10.17116/sudmed20165917-12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The objective of the present study was to elaborate the qualifying criteria for the evaluation of the severity of the harm to health in the case of development of a psychic disease associated with the concomitant HIV infection and the accompanying infectious pathology, in the first place tuberculosis, venereal diseases, parenteral hepatitis B and C. The scientifically substantiated qualifying criteria are proposed to be used for the expert assessment of the harm to health in the case of development a psychic disease associated with the concomitant HIV infection and the accompanying infectious pathology.
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Affiliation(s)
- D S Kadochnikov
- Federal state budgetary institution "Russian Centre of Forensic Medical Expertise", Russian Ministry of Health, Moscow, Russia, 125284; State budgetary educational institution of additional professional education "Russian Medical Academy of Post-Graduate Education", Russian Ministry of Health, Moscow, Russia, 125993
| | - D A Polianskiĭ
- Moscow Research Institute of Psychhiatry affiliated with the federal state budgetary institution V.P. Serbsky Medical Research Centre of Psychiatry and Narcology", Russian Ministry of Health, Moscow, Russia, 107076
| | - P V Minaeva
- Federal state budgetary institution "Russian Centre of Forensic Medical Expertise", Russian Ministry of Health, Moscow, Russia, 125284
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Nobach D, Bourg M, Herzog S, Lange-Herbst H, Encarnação JA, Eickmann M, Herden C. Shedding of Infectious Borna Disease Virus-1 in Living Bicolored White-Toothed Shrews. PLoS One 2015; 10:e0137018. [PMID: 26313904 PMCID: PMC4552160 DOI: 10.1371/journal.pone.0137018] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 08/10/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Many RNA viruses arise from animal reservoirs, namely bats, rodents and insectivores but mechanisms of virus maintenance and transmission still need to be addressed. The bicolored white-toothed shrew (Crocidura leucodon) has recently been identified as reservoir of the neurotropic Borna disease virus 1 (BoDV-1). PRINCIPAL FINDINGS Six out of eleven wild living bicoloured white-toothed shrews were trapped and revealed to be naturally infected with BoDV-1. All shrews were monitored in captivity in a long-term study over a time period up to 600 days that differed between the individual shrews. Interestingly, all six animals showed an asymptomatic course of infection despite virus shedding via various routes indicating a highly adapted host-pathogen interaction. Infectious virus and viral RNA were demonstrated in saliva, urine, skin swabs, lacrimal fluid and faeces, both during the first 8 weeks of the investigation period and for long time shedding after more than 250 days in captivity. CONCLUSIONS The various ways of shedding ensure successful virus maintenance in the reservoir population but also transmission to accidental hosts such as horses and sheep. Naturally BoDV-1-infected living shrews serve as excellent tool to unravel host and pathogen factors responsible for persistent viral co-existence in reservoir species while maintaining their physiological integrity despite high viral load in many organ systems.
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Affiliation(s)
- Daniel Nobach
- Institute of Veterinary Pathology, Justus-Liebig-University, Giessen, Germany
| | - Manon Bourg
- Institute of Veterinary Pathology, Justus-Liebig-University, Giessen, Germany
| | - Sibylle Herzog
- Institute of Virology, Justus-Liebig-University, Giessen, Germany
| | | | - Jorge A. Encarnação
- Mammalian Ecology Group, Department of Animal Ecology and Systematics, Justus-Liebig-University, Giessen, Germany
| | - Markus Eickmann
- Institute of Virology, Philipps-University, Marburg, Germany
| | - Christiane Herden
- Institute of Veterinary Pathology, Justus-Liebig-University, Giessen, Germany
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4
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Rasool V, Rasool S, Mushtaq S. Viral encephalitis and its management through advanced molecular diagnostic methods: a review. Clin Pediatr (Phila) 2014; 53:118-20. [PMID: 23737611 DOI: 10.1177/0009922813490229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Vamiq Rasool
- 1G.B. Pant Hospital, Government Medical College, Srinagar, Kashmir, India
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El-Amin EO, Elbashir MIH, Elamin OE, Mukhtar Y, Abdo H, Abdul-Rahman I, El-Amin ME. The underlying aetiologies of coma in febrile Sudanese children. Trans R Soc Trop Med Hyg 2013; 107:307-12. [PMID: 23584374 DOI: 10.1093/trstmh/trt013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Cerebral malaria, acute bacterial meningitis and viral encephalitis are the main causes of fever and altered consciousness in the tropics. In areas where reliable laboratory testing is unavailable, over diagnosis and misdiagnosis of these conditions is likely. In malaria endemic countries non-malarial contributors to coma may be overlooked, overburdening available resources. The aim of this study is to evaluate the underlying causes of altered mental state in children presenting with fever and coma to tertiary medical facilities in Sudan. METHODS Children over one month of age admitted to the emergency departments of three main hospitals in Khartoum with fever and coma were investigated for cerebral malaria, acute bacterial meningitis and Herpes simplex encephalitis during April to November 2011. RESULTS One hundred and four children presenting with fever and coma were evaluated. Cerebral malaria was clinically suspected in 38 patients and 5 were confirmed. Acute bacterial meningitis was suspected in 63 patients and confirmed in 15. Herpes encephalitis was confirmed in only one case. There were five cases of mixed infection and the remainder were unknown. CONCLUSION The clinical diagnoses of cerebral malaria, acute bacterial meningitis and viral encephalitis are unreliable. Further studies to evaluate the underlying causes of coma in febrile Sudanese children are warranted.
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Affiliation(s)
- Eisa O El-Amin
- Paediatric Department, The National Ribat University, PO Box Burri 55, Khartoum, Sudan.
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6
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Menghani S, Chikhale R, Raval A, Wadibhasme P, Khedekar P. Chandipura Virus: an emerging tropical pathogen. Acta Trop 2012; 124:1-14. [PMID: 22721825 DOI: 10.1016/j.actatropica.2012.06.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 05/30/2012] [Accepted: 06/08/2012] [Indexed: 10/28/2022]
Abstract
Chandipura Virus (CHPV), a member of Rhabdoviridae, is responsible for an explosive outbreak in rural areas of India. It affects mostly children and is characterized by influenza-like illness and neurologic dysfunctions. It is transmitted by vectors such as mosquitoes, ticks and sand flies. An effective real-time one step reverse-transcriptase PCR assay method is adopted for diagnosis of this virus. CHPV has a negative sense RNA genome encoding five different proteins (N, P, M, G, and L). P protein plays a vital role in the virus's life cycle, while M protein is lethal in nature. There is no specific treatment available to date, symptomatic treatment involves use of mannitol to reduce brain edema. A Vero cell based vaccine candidate against CHPV was evaluated efficiently as a preventive agent against it. Prevention is the best method to suppress CHPV infection. Containment of disease transmitting vectors, maintaining good nutrition, health, hygiene and awareness in rural areas will help in curbing the menace of CHPV. Thus, to control virus transmission some immense preventive measures need to be attempted until a good anti-CHPV agent is developed.
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7
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Delwart E. Human parvovirus 4 in the blood supply and transmission by pooled plasma-derived clotting factors: does it matter? Transfusion 2012; 52:1398-403. [PMID: 22780892 DOI: 10.1111/j.1537-2995.2012.03721.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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8
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Abstract
Glycemic control is an important aspect of patient care in the surgical Infections of the nervous system are among the most difficult infections in terms of the morbidity and mortality posed to patients, and thereby require urgent and accurate diagnosis. Although viral meningitides are more common, it is the bacterial meningitides that have the potential to cause a rapidly deteriorating condition that the physician should be familiar with. Viral encephalitis frequently accompanies viral meningitis, and can produce focal neurologic findings and cognitive difficulties that can mimic other neurologic disorders. Brain abscesses also have the potential to mimic and present like other neurologic disorders, and cause more focal deficits. Finally, other infectious diseases of the central nervous system, such as prion disease and cavernous sinus thrombosis, are explored in this review.
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Affiliation(s)
- Vevek Parikh
- University of California, San Francisco, CA, USA
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9
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Furr SR, Marriott I. Viral CNS infections: role of glial pattern recognition receptors in neuroinflammation. Front Microbiol 2012; 3:201. [PMID: 22723794 PMCID: PMC3379540 DOI: 10.3389/fmicb.2012.00201] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 05/15/2012] [Indexed: 12/13/2022] Open
Abstract
Viruses are the major causative agents of central nervous system (CNS) infection worldwide. RNA and DNA viruses trigger broad activation of glial cells including microglia and astrocytes, eliciting the release of an array of mediators that can promote innate and adaptive immune responses. Such responses can limit viral replication and dissemination leading to infection resolution. However, a defining feature of viral CNS infection is the rapid onset of severe neuroinflammation and overzealous glial responses are associated with significant neurological damage or even death. The mechanisms by which microglia and astrocytes perceive neurotropic RNA and DNA viruses are only now becoming apparent with the discovery of a variety of cell surface and cytosolic molecules that serve as sensors for viral components. In this review we discuss the role played by members of the Toll-like family of pattern recognition receptors (PRRs) in the inflammatory responses of glial cells to the principle causative agents of viral encephalitis. Importantly, we also describe the evidence for the involvement of a number of newly described intracellular PRRs, including retinoic acid-inducible gene I and DNA-dependent activator of IFN regulatory factors, that are thought to function as intracellular sensors of RNA and DNA viruses, respectively. Finally, we explore the possibility that cross-talk exists between these disparate viral sensors and their signaling pathways, and describe how glial cytosolic and cell surface/endosomal PRRs could act in a cooperative manner to promote the fulminant inflammation associated with acute neurotropic viral infection.
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Affiliation(s)
| | - Ian Marriott
- Department of Biology, University of North Carolina at Charlotte,Charlotte, NC, USA
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10
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Solomon T, Michael BD, Smith PE, Sanderson F, Davies NWS, Hart IJ, Holland M, Easton A, Buckley C, Kneen R, Beeching NJ. Management of suspected viral encephalitis in adults--Association of British Neurologists and British Infection Association National Guidelines. J Infect 2012; 64:347-73. [PMID: 22120595 DOI: 10.1016/j.jinf.2011.11.014] [Citation(s) in RCA: 224] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 11/13/2011] [Indexed: 12/25/2022]
Abstract
In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines. In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.
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Affiliation(s)
- T Solomon
- Institute of Infection and Global Health, University of Liverpool, The Apex Building, West Derby Street, Liverpool, UK.
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11
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Nickerson JP, Richner B, Santy K, Lequin MH, Poretti A, Filippi CG, Huisman TAGM. Neuroimaging of pediatric intracranial infection--part 2: TORCH, viral, fungal, and parasitic infections. J Neuroimaging 2012; 22:e52-63. [PMID: 22309611 DOI: 10.1111/j.1552-6569.2011.00699.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In the second half of this 2-part review, the neuroimaging features of the most common viral, fungal, and parasitic infections of the pediatric central nervous system are discussed. Brief discussions of epidemiology and pathophysiology will be followed by a review of the imaging findings and potential differential considerations.
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Affiliation(s)
- Joshua P Nickerson
- Divisions of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Hospital, Baltimore, MD, USA
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12
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Kneen R, Michael BD, Menson E, Mehta B, Easton A, Hemingway C, Klapper PE, Vincent A, Lim M, Carrol E, Solomon T. Management of suspected viral encephalitis in children - Association of British Neurologists and British Paediatric Allergy, Immunology and Infection Group national guidelines. J Infect 2011; 64:449-77. [PMID: 22120594 DOI: 10.1016/j.jinf.2011.11.013] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 11/13/2011] [Indexed: 12/25/2022]
Abstract
In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to-day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines. In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.
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Affiliation(s)
- R Kneen
- Alder Hey Children's NHS Foundation Trust, West Derby, Liverpool L12 2AP, UK.
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13
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Abstract
Encephalitis generally results in a serious illness requiring hospitalization. The aim of this study was to describe the epidemiology of hospitalization for encephalitis in Italy, taking into account the geographical distribution, aetiology, seasonality and evolution of hospitalization rates over recent years. The mean hospitalization rate was 5·88/100 000. For most of these hospitalizations (n=13 119, 55·6%), no specific cause of encephalitis was reported. The most common aetiological category was 'viral', which accounted for 40·1% (n=4205) of such hospitalizations (rate 1·05/100 000). Within this category, herpes virus was the leading causative agent (n=1579, 0·39/100 000). This report highlights a significant increase of 'viral encephalitis not otherwise specified' (ICD-9 code 049·9) vs. a reduction of all other causes. A seasonal pattern was noted in people aged ≥65 years in this group. Specific surveillance of encephalitis without known origin should be reinforced in order to identify the potential role of emerging pathogens and to design preventive interventions.
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Abstract
Headache is the most common symptom that humans experience. While the vast majority of headaches are due to benign primary headache disorders, a small but important minority of headaches are due to secondary causes. Whereas significant emphasis is placed on educating physicians regarding prompt recognition of subarachnoid hemorrhage and headaches secondary to brain tumors, attention toward headaches secondary to infectious causes is often neglected. Unfortunately, a missed or delayed diagnosis of a headache secondary to meningitis, encephalitis, brain abscess, subdural empyema, or other infectious etiologies can lead to dire consequences for both the patient and physician. Accordingly, this article provides an overview of headaches attributed to systemic and intracranial infectious causes.
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Pabbaraju K, Ho KCY, Wong S, Fox JD, Kaplen B, Tyler S, Drebot M, Tilley PAG. Surveillance of mosquito-borne viruses in Alberta using reverse transcription polymerase chain reaction with generic primers. JOURNAL OF MEDICAL ENTOMOLOGY 2009; 46:640-648. [PMID: 19496438 DOI: 10.1603/033.046.0332] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Mosquitoes collected during 2003, 2004, and 2005 in Alberta, Canada, were screened for the presence of a wide range of arboviruses by reverse transcription-polymerase chain reaction (RT-PCR). Nucleic acid extracts from mosquito slurries were amplified using universal primers designed to detect viruses belonging to the Flavivirus genus of the Flaviviridae family and California and Bunyamwera serogroups of the Bunyavirus genus within the Bunyaviridae family. Species-specific detection of Western equine encephalitis virus and Eastern equine encephalitis virus was also performed. Amplified products were analyzed, and the viral target was identified by sequencing. Of the 418 pools tested, 3 pools contained Cache Valley virus belonging to Bunyaviridae and 103 pools were positive for a previously undescribed flaviviral sequence that was most similar to Kamiti River virus. These data suggest that nucleic acid amplification using broadly reactive primers can be adopted for arbovirus surveillance in mosquito populations, and this approach has the potential to detect both previously recognized and novel viruses.
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Affiliation(s)
- Kanti Pabbaraju
- Provincial Laboratory for Public Health (Microbiology), Calgary site, 3030 Hospital Drive, Calgary, Alberta, Canada T2N 4W4.
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Early B-cell activation after West Nile virus infection requires alpha/beta interferon but not antigen receptor signaling. J Virol 2008; 82:10964-74. [PMID: 18786989 DOI: 10.1128/jvi.01646-08] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The B-cell response against West Nile virus (WNV), an encephalitic Flavivirus of global concern, is critical to controlling central nervous system dissemination and neurological sequelae, including death. Here, using a well-characterized mouse model of WNV infection, we examine the factors that govern early B-cell activation. Subcutaneous inoculation with a low dose of replicating WNV results in extensive B-cell activation in the draining lymph node (LN) within days of infection as judged by upregulation of the surface markers CD69, class II major histocompatibility complex, and CD86 on CD19(+) cells. B-cell activation in the LN but not the spleen was dependent on signals through the type I alpha/beta interferon (IFN-alpha/beta) receptor. Despite significant activation in the draining LN at day 3 after infection, WNV-specific B cells were not detected by immunoglobulin M enzyme-linked immunospot analysis until day 7. Liposome depletion experiments demonstrate that B-cell activation after WNV infection was not affected by the loss of F4/80(+) or CD169(+) subcapsular macrophages. Nonetheless, LN myeloid cells were essential for control of viral replication and survival from infection. Overall, our data suggest that the massive, early polyclonal B-cell activation occurring in the draining LN after WNV infection is immunoglobulin receptor and macrophage independent but requires sustained signals through the type I IFN-alpha/beta receptor.
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Abstract
Central nervous system (CNS) infections presenting to the emergency room include meningitis, encephalitis, brain and spinal epidural abscess, subdural empyema, and ventriculitis. These conditions often require admission to an intensive care unit (ICU) and are complications of ICU patients with neurologic injury, contributing significantly to morbidity and mortality. Reducing morbidity and mortality is critically dependent on rapid diagnosis and, perhaps more importantly, on the timely initiation of appropriate antimicrobial therapy. New insights into the role of inflammation and the immune response in CNS infections have contributed to development of new diagnostic strategies using markers of inflammation, and to the study of agents with focused immunomodulatory activity, which may lead to further adjunctive therapy in human disease.
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Tunkel AR, Glaser CA, Bloch KC, Sejvar JJ, Marra CM, Roos KL, Hartman BJ, Kaplan SL, Scheld WM, Whitley RJ. The management of encephalitis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis 2008; 47:303-27. [PMID: 18582201 DOI: 10.1086/589747] [Citation(s) in RCA: 648] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Guidelines for the diagnosis and treatment of patients with encephalitis were prepared by an Expert Panel of the Infectious Diseases Society of America. The guidelines are intended for use by health care providers who care for patients with encephalitis. The guideline includes data on the epidemiology, clinical features, diagnosis, and treatment of many viral, bacterial, fungal, protozoal, and helminthic etiologies of encephalitis and provides information on when specific etiologic agents should be considered in individual patients with encephalitis.
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Affiliation(s)
- Allan R Tunkel
- Dept of Medicine, Monmouth Medical Center, Long Branch, New Jersey 07740, USA.
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20
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Holbrook MR, Gowen BB. Animal models of highly pathogenic RNA viral infections: encephalitis viruses. Antiviral Res 2007; 78:69-78. [PMID: 18031836 DOI: 10.1016/j.antiviral.2007.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Revised: 10/09/2007] [Accepted: 10/11/2007] [Indexed: 12/11/2022]
Abstract
The highly pathogenic RNA viruses that cause encephalitis include a significant number of emerging or re-emerging viruses that are also considered potential bioweapons. Many of these viruses, including members of the family Flaviviridae, the genus Alphavirus in the family Togaviridae, and the genus Henipavirus in the family Paramyxoviridae, circulate widely in their endemic areas, where they are transmitted by mosquitoes or ticks. They use a variety of vertebrate hosts, ranging from birds to bats, in their natural life cycle. As was discovered in the United States, the introduction of a mosquito-borne encephalitis virus such as West Nile virus can cause significant health and societal concerns. There are no effective therapeutics for treating diseases caused by any of these viruses and there is limited, if any, vaccine availability for most. In this review we provide a brief summary of the current status of animal models used to study highly pathogenic encephalitic RNA viruses for the development of antiviral therapeutics and vaccines.
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Affiliation(s)
- Michael R Holbrook
- Department of Pathology, 301 University Boulevard, University of Texas Medical Branch, Galveston, TX 77555-0609, United States.
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Abstract
The environment has profound influences on human health. Environment is the combination of natural (physical, chemical, biological) and cultural (sociological) conditions in which living organisms, man in particular, develop. Adaptation is the human physiological response to external factors including mechanisms such as circadian rhythms (sleep and wakefulness), biorhythms, thermoregulation, and others to adjust to changes in natural conditions (night and day, cosmic rhythms, climatic changes). Man remains vulnerable due to a number of factors: genetic, physiological, age, sex, impaired reparative or protective mechanisms, or acquired factors (risky behaviors and lifestyle, nutritional habits). Hazard is the potential of a particular factor to have a negative impact on health. Risk is the probability of that hazard occurring; it defines and measures the predictability of that hazard. A number of environmental factors have a profound influence on the pathogenesis of neurological disorders. Environmental neurology follows the classical diagnostic precepts: from symptom to syndrome in the search for etiology and individualized treatment of the patient. It also utilizes principles of epidemiology and public health, toxicology and occupational medicine; i.e., an approach by "milieu" and by specific factors or "agents." Environmental neurology offers a promising new field of practice and research.
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Ziai WC, Lewin JJ. Advances in the management of central nervous system infections in the ICU. Crit Care Clin 2007; 22:661-94; abstract viii-ix. [PMID: 17239749 DOI: 10.1016/j.ccc.2006.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This chapter focuses on early aggressive management of common infections of the central nervous system that require monitoring in an ICU setting. These include meningitis, encephalitis, brain and epidural abscess, subdural empyema and ventriculitis. It emphasizes priorities in evaluation and management due to increasing morbidity and mortality as a result of failure to appreciate non-specific symptoms or administer timely therapy. The emergence of organisms resistant to penicillin and cephalosporins has also further complicated the early management of bacterial meningitis. Current antimicrobial guidelines are provided along with discussion of new diagnostic and therapeutic strategies and controversial aspects of management.
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Affiliation(s)
- Wendy C Ziai
- Division of Neurosciences Critical Care, Department of Neurology, The Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
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