title: Morbidity and mortality of elderly patients with zoonotic Salmonella and Campylobacter: a population-based study.
abstract: OBJECTIVE
  To evaluate the impact of age and comorbidity on the risk and prognosis of zoonotic Salmonella and Campylobacter gastroenteritis in elderly individuals.
  
  
  METHODS
  Registry-based study comprising all first-time zoonotic Salmonella/Campylobacter gastroenteritis infections in two Danish counties from 1991 through 2003. Cases were elderly (>or=65 years) Salmonella/Campylobacter patients. Younger Salmonella/Campylobacter patients and age and gender matched individuals were reference persons.
  
  
  RESULTS
  There were 13,324 Salmonella/Campylobacter patients (including 1226 elderly patients) and 26,648 matched reference persons. Elderly Salmonella/Campylobacter patients had more comorbidity than their matched reference persons (OR [95% CI]: 1.56 [1.35-1.80]) and comorbidity adjusted mortality rate ratios (95% CI) were 11.4 (5.1-25.4), 1.9 (1.4-2.6), and 1.3 (0.9-1.9) at day 0-30, 31-180, and 181-365, respectively. The differences in crude 365-day mortality increased with age when Salmonella/Campylobacter patients and reference persons without comorbidity were compared. The independent impact of age was less clear for individuals with comorbidity. There were no differences in comorbidity or survival between non-hospitalized elderly patients and their matched reference persons.
  
  
  CONCLUSIONS
  Elderly hospitalized Salmonella/Campylobacter patients had higher comorbidity and 1-year mortality than the background population. The excess 30-day mortality elucidated the prognostic role of the Salmonella/Campylobacter infection per se.
authors.affiliation: Department of Infectious Diseases, Medicinerhuset, Mølleparkvej 4, Aalborg Hospital, Aarhus University Hospital, 9000 Aalborg, Denmark. kog@rn.dk
authors.forename: Kim O
authors.initials: KO
authors.lastname: Gradel
authors.forename: Henrik C
authors.initials: HC
authors.lastname: Schønheyder
authors.forename: Claus
authors.initials: C
authors.lastname: Dethlefsen
authors.forename: Brian
authors.initials: B
authors.lastname: Kristensen
authors.forename: Tove
authors.initials: T
authors.lastname: Ejlertsen
authors.forename: Henrik
authors.initials: H
authors.lastname: Nielsen
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002169:Campylobacter Infections / Q000453:epidemiology* / Q000401:mortality*; D016022:Case-Control Studies; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology / Q000401:mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D011379:Prognosis; D012307:Risk Factors; D012480:Salmonella Infections / Q000453:epidemiology* / Q000401:mortality*; D015047:Zoonoses / Q000453:epidemiology*