title: Listeriosis in Portugal: an existing but under reported infection.
abstract: BACKGROUND
  Listeriosis is a rare disease caused by the bacterium Listeria monocytogenes, the normal vehicle of which is food. The disease, which is largely confined to its risk groups of pregnant women, the elderly and immunocompromised individuals, has increased in incidence in recent years. In Portugal, listeriosis is not a notifiable infection and available data are scarce. The objective of this work was to collate the available information concerning listeriosis in Portugal by compiling a retrospective study of cases recorded over a decade.
  
  
  METHODS
  Requests for case data on clinically confirmed listeriosis, recorded over the previous decade, were replied to by 23 hospitals and a National Institute of Health delegation.
  
  
  RESULTS
  35 cases of listeriosis were identified for the period between 1994 and 2003 inclusive, the mortality rate being greater than 17%. According to the data collected in this study for the year 2003, the incidence of this disease in Portugal was at least 1.4 cases per million inhabitants in that year.
  
  
  CONCLUSIONS
  The study demonstrates, for the first time in the widely available literature, that despite their being no cases of listeriosis in Portugal recorded in official reports, the threat of L. monocytogenes to public health is of a similar dimension to that in other countries.
authors.affiliation: Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr, António Bernardino de Almeida, 4200-072 Porto, Portugal. gnalmeida@esb.ucp.pt
authors.forename: Gonçalo N
authors.initials: GN
authors.lastname: Almeida
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gibbs
authors.forename: Tim A
authors.initials: TA
authors.lastname: Hogg
authors.forename: Paula C
authors.initials: PC
authors.lastname: Teixeira
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008088:Listeriosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology