title: Salmonella enterica serotype Enteritidis: increasing incidence of domestically acquired infections.
abstract: BACKGROUND
  Salmonella enterica causes an estimated 1 million cases of domestically acquired foodborne illness in humans annually in the United States; Enteritidis (SE) is the most common serotype. Public health authorities, regulatory agencies, food producers, and food processors need accurate information about rates and changes in SE infection to implement and evaluate evidence-based control policies and practices.
  
  
  METHODS
  We analyzed the incidence of human SE infection during 1996-2009 in the Foodborne Diseases Active Surveillance Network (FoodNet), an active, population-based surveillance system for laboratory-confirmed infections. We compared FoodNet incidence with passively collected data from complementary surveillance systems and with rates of SE isolation from processed chickens and egg products; shell eggs are not routinely tested. We also compared molecular subtyping patterns of SE isolated from humans and chickens.
  
  
  RESULTS
  Since the period 1996-1999, the incidence of human SE infection in FoodNet has increased by 44%. This change is mirrored in passive national surveillance data. The greatest relative increases were in young children, older adults, and FoodNet sites in the southern United States. The proportion of patients with SE infection who reported recent international travel has decreased in recent years, whereas the proportion of chickens from which SE was isolated has increased. Similar molecular subtypes of SE are commonly isolated from humans and chickens.
  
  
  CONCLUSIONS
  Most SE infections in the United States are acquired from domestic sources, and the problem is growing. Chicken and eggs are likely major sources of SE. Continued close attention to surveillance data is needed to monitor the impact of recent regulatory control measures.
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. schai@cdc.gov
authors.forename: Shua J
authors.initials: SJ
authors.lastname: Chai
authors.forename: Patricia L
authors.initials: PL
authors.lastname: White
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Lathrop
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Solghan
authors.forename: Carlota
authors.initials: C
authors.lastname: Medus
authors.forename: Beth M
authors.initials: BM
authors.lastname: McGlinchey
authors.forename: Melissa
authors.initials: M
authors.lastname: Tobin-D'Angelo
authors.forename: Ruthanne
authors.initials: R
authors.lastname: Marcus
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Mahon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000822:Animal Husbandry / Q000592:standards; D000818:Animals; D002645:Chickens / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004531:Eggs / Q000382:microbiology; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011159:Population Surveillance; D012044:Regression Analysis; D012307:Risk Factors; D012480:Salmonella Infections / Q000453:epidemiology* / Q000635:transmission; D012477:Salmonella enteritidis / Q000302:isolation & purification*; D014195:Travel; D014481:United States / Q000453:epidemiology; D055815:Young Adult