Epidemiology of infectious encephalitis causes in 2016.
We performed a literature search in the Medline database, using the PubMed website. The incidence of presumably infectious encephalitis is estimated at 1.5-7 cases/100,000 inhabitants/year, excluding epidemics. Infectious encephalitis and immune-mediated encephalitis share similar clinical signs and symptoms. The latter accounts for a significant proportion of presumably infectious encephalitis cases without any established etiological diagnosis; as shown from a prospective cohort study where 21% of cases were due to an immune cause. Several infectious agents are frequently reported in all studies: Herpes simplex virus (HSV) is the most frequent pathogen in 65% of studies, followed by Varicella-zoster virus (VZV) in several studies. Enteroviruses are also reported; being the most frequent viruses in two studies, and the 2nd or 3rd viruses in five other studies. There are important regional differences, especially in case of vector-borne transmission: Asia and the Japanese encephalitis virus, Eastern and Northern Europe/Eastern Russia and the tick-borne encephalitis virus, Northern America and Flavivirus or Alphavirus. Bacteria can also be incriminated: Mycobacterium tuberculosis and Listeria monocytogenes are the most frequent, after HSV and VZV, in a French prospective study. The epidemiology of encephalitis is constantly evolving. Epidemiological data may indicate the emergence and/or dissemination of new causative agents. The dissemination and emergence of causative agents are fostered by environmental, social, and economical changes, but prevention programs (vaccination, vector controls) help reduce the incidence of other infectious diseases and associated encephalitis (e.g., measles).
Maladies infectieuses, CHU de Lille, 59000 Lille, France.
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A
Boucher
Microbiologie, CHU de Garches, 92380 Garches, France.
J L
JL
Herrmann
Virologie, CHU Grenoble Alpes, 38700 La Tronche, France.
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P
Morand
Médecine interne, centre hospitalier de Saint-Brieuc, 22027 Saint-Brieuc, France.
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R
Buzelé
Médecine interne, centre hospitalier Vannes-Aufray, 56000 Vannes, France.
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Y
Crabol
Maladies infectieuses, CHU Grenoble Alpes, Grenoble - "European Study Group for the Infections of the Brain (ESGIB)", 38700 La Tronche, France. Electronic address: JPStahl@chu-grenoble.fr.
J P
JP
Stahl
Direction des maladies infectieuses, santé publique France - "European Study Group for the Infections of the Brain (ESGIB)", 94410 Saint-Maurice, France.
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A
Mailles
D000328:Adult; D000818:Animals; D001424:Bacterial Infections / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005602:France / Q000453:epidemiology; D014943:Global Health; D006801:Humans; D016867:Immunocompromised Host; D015994:Incidence; D000069544:Infectious Encephalitis / Q000453:epidemiology* / Q000209:etiology; D010272:Parasitic Diseases / Q000453:epidemiology; D014611:Vaccination; D014777:Virus Diseases / Q000453:epidemiology / Q000635:transmission; D015047:Zoonoses
Emerging infections; Encephalitis; Encéphalite; Enterovirus; Entérovirus; Epidemiology; HSV; Infections émergentes; VZV; Épidémiologie