title: Seven-fold increase in viral meningo-encephalitis reports in England and Wales during 2004-2013.
abstract: OBJECTIVE
  In highly immunised populations viruses contribute to a substantially higher proportion of meningo-encephalitis cases. This national study aimed to describe population trends in laboratory-confirmed, viral meningo-encephalitis reports in England and Wales over a ten-year period.
  
  
  METHODS
  Laboratory-confirmed, viral meningo-encephalitis cases submitted by National Health Service hospitals in England and Wales during 2004-13 were analysed.
  
  
  RESULTS
  There were 9941 laboratory-confirmed reports of viral meningo-encephalitis in England and Wales over the 10-year period. Number of reports increased across all age-groups and for all viruses from 311 (incidence, 0.6/100,000) in 2004 to 2168 in 2013 (incidence, 3.9/100,000). Median age at diagnosis was 30.6 (IQR, 1.3-51.5) years, with a third of cases diagnosed in children. In 2013, infants aged <3 months accounted for 27% (588/2168) of cases, but had the highest incidence (329/100,000). Enteroviruses were responsible for 52% (5133/9941) of all cases and 92% (1952/2121) in <3 month-olds (incidence, 313/100,000 in 2013, equivalent to 77/100,000 live-births) followed by herpes simplex (2885/9941; 29%) and varicella zoster (1342/9941; 13%), mainly among ≥45 year-olds.
  
  
  CONCLUSIONS
  Increasing use of molecular testing has led to a 7-fold increase in laboratory-confirmed, viral meningo-encephalitis reports. Large clinical-observational studies are necessary to determine the burden of viral meningo-encephalitis, especially in infants.
authors.affiliation: Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: Seilesh
authors.initials: S
authors.lastname: Kadambari
authors.affiliation: Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: Ifeanyichukwu
authors.initials: I
authors.lastname: Okike
authors.affiliation: Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Sonia
authors.initials: S
authors.lastname: Ribeiro
authors.affiliation: Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Ramsay
authors.affiliation: Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Heath
authors.affiliation: Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Sharland
authors.affiliation: Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK; Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK. Electronic address: shamez.ladhani@phe.gov.uk.
authors.forename: Shamez N
authors.initials: SN
authors.lastname: Ladhani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D018792:Encephalitis, Viral / Q000453:epidemiology* / Q000821:virology; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008587:Meningitis, Viral / Q000453:epidemiology* / Q000821:virology; D008875:Middle Aged; D014852:Wales / Q000453:epidemiology; D055815:Young Adult
keywords: Genotyping; Meningitis; Surveillance; Virus