title: Changing epidemiology of Yersinia enterocolitica infections: markedly decreased rates in young black children, Foodborne Diseases Active Surveillance Network (FoodNet), 1996-2009.
abstract: BACKGROUND
  Yersinia enterocolitica causes an estimated 116,716 illnesses annually in the United States. Black children have historically had the highest rates of infection, with incidence peaking in the winter.
  
  
  METHODS
  The Foodborne Diseases Active Surveillance Network (FoodNet) conducts active surveillance for laboratory-confirmed Y. enterocolitica infections, defined as the isolation of Y. enterocolitica or unspeciated Yersinia from a human clinical specimen. We calculated the average annual crude incidence rate per 100,000 persons from 1996 through 2009 and described rates by age, race, and geographic site. To account for changes in the FoodNet catchment area, we used a negative binomial model to estimate statistical changes in incidence using the average annual incidence in 1996-1998 as the baseline.
  
  
  RESULTS
  From 1996 through 2009, 2085 Y. enterocolitica infections were reported to FoodNet. The average annual crude incidence was 0.5 per 100,000 persons and was highest in blacks (0.9 per 100,000 persons). Over time, the rate in blacks declined from 3.9 to 0.4 per 100,000 persons. Declines among other racial groups were not as pronounced. The largest decline occurred in black children <5 years old (from 41.5 per 100,000 persons in 1996 to 3.5 per 100,000 persons in 2009). From 2007 through 2009, the highest rate of infection was in Asian children (5.1 per 100,000 persons). Compared with 1996-1998, the incidence in 2009 was 66% (95% confidence interval, 51%-77%) lower among children <5 years old.
  
  
  CONCLUSIONS
  Y. enterocolitica infections in FoodNet sites have significantly declined since 1996. These declines were greatest in young black children, the group that initially had the highest incidence, possibly as the result of educational efforts in Georgia.
authors.affiliation: Enteric Diseases Epidemiology Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, C09, Atlanta, GA 30333, USA.
authors.forename: Kanyin L
authors.initials: KL
authors.lastname: Ong
authors.forename: L Hannah
authors.initials: LH
authors.lastname: Gould
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Chen
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Jones
authors.forename: Joni
authors.initials: J
authors.lastname: Scheftel
authors.forename: Tameka Hayes
authors.initials: TH
authors.lastname: Webb
authors.forename: Rajal K
authors.initials: RK
authors.lastname: Mody
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Mahon
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000208:ethnology*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People; D002487:Centers for Disease Control and Prevention, U.S.; D002648:Child; D002675:Child, Preschool; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000208:ethnology; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012307:Risk Factors; D012621:Seasons; D014481:United States / Q000453:epidemiology; D015009:Yersinia Infections / Q000208:ethnology*; D015008:Yersinia enterocolitica / Q000302:isolation & purification*; D055815:Young Adult