Question 1 of 10

    Arbovirus Encephalitis (Arthropod-Borne Encephalitis)

    Arbovirus encephalitis is a general term that refers to an inflammation of the brain due to an infection with viral pathogens transmitted by arthropods.

    Presentation

    Pathogens are inoculated peripherally, replicate and disseminate through the bloodstream. In immunocompetent patients, this process is generally associated with seroconversion and results in virus clearance. Thus, most patients who contract an arbovirus infection remain asymptomatic or merely develop flu-like symptoms. Neuroinvasion and AE are more likely in those individuals suffering from an immune system disorder, receiving immunosuppressive medication, and the elderly, and occurs in less than 1% of cases [7].

    After an incubation period of a few days, AE patients start to suffer from flu-like symptoms such as fever, headaches, and myalgia. A short period of apparent resolution may pass until additional symptoms manifest, namely nausea, vomiting and meningism with neck stiffness [3]. The onset of neurological symptoms clearly indicates central nervous system involvement, and patients may present with an altered mental status, tremor, myoclonic jerks, seizures, limb weakness, paralysis, and photophobia. Reduced consciousness ranging from somnolence to coma may be observed.

    AE-associated symptoms generally persist for few weeks, but may occasionally last several months.

    Entire body system
  • more...
  • neurologic
    Rabies
    • […] encephalitis virus Western equine encephalitis virus Venezuelan equine encephalitis virus Murray Valley encephalitis virus Tick-borne meningoencephalitis Powassan encephalitis West Nile virus Herpes simplex Human herpesvirus 6 Varicella zoster virus Rabies[en.wikipedia.org]
    • Rarest in the United States are the 0-3 unrelated annual cases of rabies encephalitis, typically a consequence of the immigration of an infected person from Mexico or Central America during the long incubation period of the rabies virus but prior to the[emedicine.medscape.com]
    • Rabies Tests Prospective submitters must contact the Rabies Laboratory Director at (518) 485-6464 or (518) 527-7369 prior to sending samples for testing.[wadsworth.org]
    • […] system Encephalitis / meningitis DNA virus JCV Progressive multifocal leukoencephalopathy RNA virus MeV Subacute sclerosing panencephalitis LCV Lymphocytic choriomeningitis Arbovirus encephalitis Orthomyxoviridae (probable) Encephalitis lethargica RV Rabies[en.wikipedia.org]
    • Arboviruses are the most common cause of equine encephalitis, but rabies virus, Sarcocystis neurona (see Equine Protozoal Myeloencephalitis ), Neospora hughesii (see Neosporosis ), equine herpesviruses, and several bacteria and nematodes may also cause[merckvetmanual.com]
    Seizure
    • It is unclear if anticonvulsants used in people with viral encephalitis would prevent seizures.[en.wikipedia.org]
    • Long-term sequelae with St Louis encephalitis include behavioral disorders, memory loss, and seizures.[emedicine.medscape.com]
    • Herpes -related encephalitis can erupt rapidly, and may cause seizures or mental changes and even lead to coma or death.[webmd.com]
    • Anticonvulsant drugs, including phenytoin, are used to control seizures.[healthofchildren.com]
  • more...
  • Skin
  • more...
  • Eyes
  • more...
  • Workup

    Symptoms presented in the case of AE are unspecific. The consideration of anamnestic data is of utmost importance at the time of establishing a list of differential diagnoses. Patients should be queried about recent journeys and stays in endemic areas as described above.

    The following diagnostic measures may be undertaken to confirm a tentative diagnosis of AE:

    • Proof of seroconversion.
    • An analysis of cerebrospinal fluid regarding the presence of immunoglobulin-M (IgM) antibodies against either of the pathogens described above, is considered the gold standard for the detection of neuroinvasive arboviruses and AE [8].
    • Determination of cerebrospinal fluid/serum antibody ratios, with high ratios indicating central nervous system disease.
    • Detection of antigens or nucleic acid by means of molecular biological assays such as polymerase chain reaction, using serum or cerebrospinal fluid samples, (preferred in immunocompromised patients) [9] [10].
    • Isolation and culture of arboviruses (although difficult and not routinely performed).

    Laboratory

    Microbiology
    Human Herpesvirus 6
    • Louis encephalitis Eastern equine encephalitis virus Western equine encephalitis virus Venezuelan equine encephalitis virus Murray Valley encephalitis virus Tick-borne meningoencephalitis Powassan encephalitis West Nile virus Herpes simplex Human herpesvirus[en.wikipedia.org]
    • Human herpesvirus 6 may also be a causative agent. [4] The CDC has confirmed that WNV can be transmitted by means of organ transplantation and via blood transfusions.[emedicine.medscape.com]
  • more...
  • Treatment

    Prognosis

    Complications

    Arbovirus Encephalitis
    • Arbovirus Encephalitis Definition Encephalitis is a serious inflammation of the brain, Arbovirus encephalitis is caused by a virus from the Arbovirus group.[medical-dictionary.thefreedictionary.com]
    • Types of encephalitis in humans include: Arbovirus encephalitis La Crosse encephalitis Enterovirus California encephalitis virus Japanese encephalitis St.[en.wikipedia.org]
    California Encephalitis
    • Aliases Arbovirus Arbovirus CSF antibodies California Encephalitis Antibody, IgG CSF California Encephalitis Antibody, IgM CSF Eastern Equine Encephalitis Antibody, IgG CSF Eastern Equine Encephalitis Antibody, IgM CSF St.[ltd.aruplab.com]
    • Types of encephalitis in humans include: Arbovirus encephalitis La Crosse encephalitis Enterovirus California encephalitis virus Japanese encephalitis St.[en.wikipedia.org]
    • California encephalitis The California encephalitis virus belongs to the Bunyaviridae family.[merckmanuals.com]
    • Louis encephalitis, and California encephalitis.[medical-dictionary.thefreedictionary.com]
    • Examples include California encephalitis, Chikungunya, dengue, Eastern equine encephalitis, Powassan, St.[health.ny.gov]
    Eastern Equine Encephalitis
    • Aliases Arbovirus Arbovirus CSF antibodies California Encephalitis Antibody, IgG CSF California Encephalitis Antibody, IgM CSF Eastern Equine Encephalitis Antibody, IgG CSF Eastern Equine Encephalitis Antibody, IgM CSF St.[ltd.aruplab.com]
    • Louis encephalitis Eastern equine encephalitis virus Western equine encephalitis virus Venezuelan equine encephalitis virus Murray Valley encephalitis virus Tick-borne meningoencephalitis Powassan encephalitis West Nile virus Herpes simplex Human herpesvirus[en.wikipedia.org]
    • Eastern equine encephalitis outbreaks occur most commonly in the Eastern United States.[eis.ifas.ufl.edu]
    • Eastern equine encephalitis tends to produce a more fulminant illness than LaCrosse or Western equine encephalitis.[unboundmedicine.com]
    Encephalitis
    • Types of encephalitis in humans include: Arbovirus encephalitis La Crosse encephalitis Enterovirus California encephalitis virus Japanese encephalitis St.[en.wikipedia.org]
    • Nearby & related entries: encephalitis virus, venezuelan equine encephalitis virus, western equine encephalitis viruses encephalitis viruses, japanese encephalitis viruses, tick-borne encephalitis, california encephalitis, herpes simplex encephalitis,[definitions.net]
    • Louis encephalitis, California encephalitis, and Japanese encephalitis.[healthofchildren.com]
    Hemiplegia
    • Outcomes in arboviral JE and EEE are catastrophic, similar to untreated HSE, with high mortality and severe morbidity, including mental retardation, hemiplegia, and seizures.[emedicine.medscape.com]
    Herpes Simplex Encephalitis
    • Nearby & related entries: encephalitis virus, venezuelan equine encephalitis virus, western equine encephalitis viruses encephalitis viruses, japanese encephalitis viruses, tick-borne encephalitis, california encephalitis, herpes simplex encephalitis,[definitions.net]
    • The symptoms of herpes simplex encephalitis are fever, rapidly disintegrating mental state, headache, and behavioral changes.[healthofchildren.com]
    • Herpes simplex encephalitis (HSE), which occurs sporadically in healthy and immune-compromised adults is also encountered in neonates infected at birth during vaginal delivery and is potentially lethal if not treated.[emedicine.medscape.com]
    • Electroencephalogram (EEG), which records brain waves, may reveal abnormalities in the temporal lobe that are indicative of herpes simplex encephalitis.[nytimes.com]
    Herpes Zoster
    • If it occurs as a result of herpes zoster in adults, the brain inflammation tends to be mild, except in immunocompromised patients.[nytimes.com]
    • Viruses and viral diseases that may cause encephalitis include: chickenpox measles mumps Epstein-Barr virus (EBV) cytomegalovirus infection HIV herpes simplex herpes zoster (shingles) herpes B polio rabies mosquito-borne viruses (arboviruses) Primary[healthofchildren.com]
    Infection
    • Other diseases spread by the bite of infected arthropods that are not viral infections, such as Lyme disease, which is a bacterial infection, and babesiosis, which is a parasitic infection, are not arboviruses.[health.ny.gov]
    • In warmer areas, infections may occur year-round.[labtestsonline.org]
    • Birds act as amplifiers of infection, each infected bird potentially infecting many mosquitoes.[fr.cwhc-rcsf.ca]
    • Prevention involves avoiding tick bites and infected animals.[merckmanuals.com]
    Japanese Encephalitis
    • Types of encephalitis in humans include: Arbovirus encephalitis La Crosse encephalitis Enterovirus California encephalitis virus Japanese encephalitis St.[en.wikipedia.org]
    • In all of these areas, Japanese encephalitis is mainly a rural disease.[hopkinsmedicine.org]
    Lymphocytic Choriomeningitis
    • choriomeningitis, which also causes encephalitis List of central nervous system infections The Encephalitis Society[en.wikipedia.org]
    • choriomeningitis Arbovirus encephalitis Orthomyxoviridae (probable) Encephalitis lethargica RV Rabies Chandipura virus Herpesviral meningitis Ramsay Hunt syndrome type 2 Myelitis Poliovirus Poliomyelitis Post-polio syndrome HTLV-I Tropical spastic paraparesis[en.wikipedia.org]
    • Important animal vectors include mosquitoes and ticks, which spread the arbovirus group, and warm-blooded mammals, which are vectors for rabies and lymphocytic choriomeningitis (LCM).[emedicine.medscape.com]
    • Viral Herpes simplex virus Enterovirus HIV HHV-6 Epstein-Barr virus Cytomegalovirus Lymphocytic choriomeningitis virus Rabies Mumps Influenza Adenovirus Nonviral Cat-scratch disease ( Bartonella henselae ) Mycoplasma pneumoniae Postinfectious encephalomyelitis[5minuteconsult.com]
    Meningoencephalitis
    • Louis encephalitis Eastern equine encephalitis virus Western equine encephalitis virus Venezuelan equine encephalitis virus Murray Valley encephalitis virus Tick-borne meningoencephalitis Powassan encephalitis West Nile virus Herpes simplex Human herpesvirus[en.wikipedia.org]
    • They can cause more serious conditions, including encephalitis , meningitis and meningoencephalitis, and can be fatal.[epi.publichealth.nc.gov]
    • Rarely, Rift Valley fever progresses to ocular disorders, meningoencephalitis, or a hemorrhagic form (which has a 50% mortality rate).[merckmanuals.com]
    • Although it primarily involves the brain, it often involves the meninges as well (meningoencephalitis).[emedicine.medscape.com]
    • Illness ranges in severity from a simple febrile headache to meningoencephalitis, with an overall case-fatality ratio of 5-15 %.[austincc.edu]
    Parainfluenza
    • […] viruses Parainfluenza RSV hMPV Human digestive system Pharynx / Esophagus MuV Mumps Cytomegalovirus Cytomegalovirus esophagitis Gastroenteritis / diarrhea DNA virus Adenovirus Adenovirus infection RNA virus Rotavirus Norovirus Astrovirus Coronavirus[en.wikipedia.org]
    Varicella
    • […] encephalitis Eastern equine encephalitis virus Western equine encephalitis virus Venezuelan equine encephalitis virus Murray Valley encephalitis virus Tick-borne meningoencephalitis Powassan encephalitis West Nile virus Herpes simplex Human herpesvirus 6 Varicella[en.wikipedia.org]
    • Varicella-zoster virus encephalitis (VZVE) is life threatening in immune-compromised patients.[emedicine.medscape.com]
    • ) X X CSF, respiratory swabs, rectal swabs and stool Herpes Simplex virus 1 X X CSF, brain suspension, genital, rectal, and lesion swabs Herpes Simplex virus 2 X X CSF, brain suspension, genital, rectal, and lesion swabs Human Herpes virus 6 X X CSF Varicella[wadsworth.org]
    • ., bacteria, fungi, and the postinfectious encephalitides that follow measles, varicella, rubella, or vaccination.[atsu.edu]
    Venezuelan Equine Encephalomyelitis
    • equine encephalomyelitis VEEV Chikungunya CHIKV O'Nyong-nyong fever ONNV Ross River fever RRV Semliki Forest virus Sindbis fever Reoviridae Banna virus encephalitis Tick-borne Bunyaviridae Viral hemorrhagic fevers : Crimean–Congo hemorrhagic fever CCHFV[en.wikipedia.org]
    West Nile Encephalitis
    • Louis encephalitis/meningitis West Nile encephalitis/meningitis Western equine encephalitis/meningitis Clinical Description Arboviral infections may be asymptomatic or may result in illnesses of variable severity sometimes associated with central nervous[wwwn.cdc.gov]
    • West Nile encephalitis (WNE) This virus first appeared in the United States in 1999.[eis.ifas.ufl.edu]
    • See the following for more information: West Nile encephalitis In 1999, a late summer outbreak of West Nile encephalitis (WNE), an arbovirus not previously found in the United States, was implicated in several deaths in New York.[emedicine.medscape.com]
    • They include Japanese encephalitis (JE), tick-borne encephalitis (TBE), Murray Valley encephalitis (MVE) and, most notorious of all, the West Nile virus (WNV) which causes West Nile encephalitis, also known as West Nile fever .[medicinenet.com]
    • While there have been outbreaks in recent years in the United States of several forms of encephalitis, such as West Nile encephalitis and St.[laketahoesurgerycenter.com]
    Western Equine Encephalomyelitis
    • equine encephalomyelitis WEEV Venezuelan equine encephalomyelitis VEEV Chikungunya CHIKV O'Nyong-nyong fever ONNV Ross River fever RRV Semliki Forest virus Sindbis fever Reoviridae Banna virus encephalitis Tick-borne Bunyaviridae Viral hemorrhagic fevers[en.wikipedia.org]
  • more...
  • Etiology

    Pathogens pertaining to distinct families of viruses may trigger the following diseases:

    Other arboviruses are primarily known to cause systemic febrile disease or hemorrhagic fever, but affected individuals may occasionally develop AE. For instance, this applies to the causative agents of Colorado tick fever, Kyasanur forest disease, and Rift Valley fever [3].

    Epidemiology

    While arboviruses are distributed throughout the world, specific viruses may only be encountered in determined geographic areas. For instance, the distribution of vectors, as well as wild animals that constitute the natural reservoir of these pathogens, may demarcate affected geographic regions. The latter, in turn, are strongly influenced by climatic conditions, and the climate change may entail the expansion of arboviruses [4]. To date, distribution patterns of AE are as follows [5]:

    Sex distribution
    Age distribution

    Pathophysiology

    Prevention

    Summary

    Arbovirus is a non-taxonomic term coined to refer to viral pathogens transmitted by arthropods. In detail, humans may contract an infection with an arthropod-borne virus after getting bitten by mosquitoes, flies or ticks. Furthermore, infected organ transplants and blood products constitute possible sources of infection [1] [2]. Patients suffering from an arbovirus infection may present with systemic febrile illness, hemorrhagic fever or encephalitis. Pathogens that may provoke arbovirus encephalitis (AE) and corresponding entities are detailed below.

    Patient Information

    Self-assessment

    Ask Question


    5000 Characters left Format the text using: # Heading, **bold**, _italic_. HTML code is not allowed.

    References

    1. Dana A, Antony A, Patel MJ. Vector-borne infections in solid organ transplant recipients. Int J Dermatol. 2012; 51(1):1-11.
    2. Macedo de Oliveira A, Beecham BD, Montgomery SP, et al. West Nile virus blood transfusion-related infection despite nucleic acid testing. Transfusion. 2004; 44(12):1695-1699.
    3. Salimi H, Cain MD, Klein RS. Encephalitic Arboviruses: Emergence, Clinical Presentation, and Neuropathogenesis. Neurotherapeutics. 2016; 13(3):514-534.
    4. Weaver SC, Reisen WK. Present and future arboviral threats. Antiviral Res. 2010; 85(2):328-345.
    5. Gubler DJ. The global emergence/resurgence of arboviral diseases as public health problems. Arch Med Res. 2002; 33(4):330-342.
    6. Guillaumot L. Arboviruses and their vectors in the Pacific--status report. Pac Health Dialog. 2005; 12(2):45-52.
    7. Davis LE, Beckham JD, Tyler KL. North American encephalitic arboviruses. Neurol Clin. 2008; 26(3):727-757, ix.
    8. Petersen LR, Marfin AA. West Nile virus: a primer for the clinician. Ann Intern Med. 2002; 137(3):173-179.
    9. Debiasi RL, Tyler KL. Molecular methods for diagnosis of viral encephalitis. Clin Microbiol Rev. 2004; 17(4):903-925, table of contents.
    10. Penn RG, Guarner J, Sejvar JJ, et al. Persistent neuroinvasive West Nile virus infection in an immunocompromised patient. Clin Infect Dis. 2006; 42(5):680-683.



    Languages