title: Diarrhea in American infants and young children in the community setting: incidence, clinical presentation and microbiology.
abstract: OBJECTIVE
  The characteristics and microbiology of the full spectrum of pediatric diarrhea occurring in the U.S. community setting are not well-understood.
  
  
  METHODS
  Six-month prospective cohort study of 604 healthy 6- to 36-month-old children recruited by the Slone Center Office-based Research Network.
  
  
  RESULTS
  The incidence of parent-defined diarrhea was 2.2 episodes per person-year. The median duration of diarrhea was 2 days with a median of 6 stools per episode. Outpatient visits and hospitalization were prompted by 9.7 and 0.3% of episodes, respectively. The most common microorganisms identified in healthy baseline stools were atypical enteropathogenic Escherichia coli (12.2%), enteroaggregative Escherichia coli (3.7%), Clostridium difficile (3.5%) and Clostridium perfringens (2.9%), and each of these was no more common in diarrhea stools. In contrast, all of the viruses analyzed were more prevalent in diarrhea specimens than in baseline specimens: enteric adenovirus (5.7% diarrhea versus 1.4% baseline), rotavirus (5.2% versus 1.4%), astrovirus (3.5% versus 1.4%), Sapporo-like virus (3.0% versus 0.8%) and norovirus (1.9% versus 0.8%). A likely pathogen was detected in 20.6% of diarrhea specimens. Vomiting and > or =16 stools in an episode were predictive of isolating a pathogen from the stool, each with a relative risk of approximately 2.
  
  
  CONCLUSIONS
  Healthy young children in this study experienced more than 2 cases of diarrhea per person-year, but most were brief and do not require medical attention. Although most diarrhea-associated pathogens were viruses, no likely pathogen was found in almost 80% of cases; possible etiologies for these cases include currently unknown gastrointestinal infections, nongastrointestinal illnesses and dietary/environmental factors.
authors.affiliation: Slone Epidemiology Center at Boston University, Tufts-New England Medical Center, Boston, MA 02115, USA. lvernacchio@slone.bu.edu
authors.forename: Louis
authors.initials: L
authors.lastname: Vernacchio
authors.forename: Richard M
authors.initials: RM
authors.lastname: Vezina
authors.forename: Allen A
authors.initials: AA
authors.lastname: Mitchell
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Lesko
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Plaut
authors.forename: David W K
authors.initials: DW
authors.lastname: Acheson
mesh_terms: D000260:Adenoviruses, Human / Q000302:isolation & purification; D002675:Child, Preschool; D016360:Clostridioides difficile / Q000302:isolation & purification; D003016:Clostridium perfringens / Q000302:isolation & purification; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology* / Q000503:physiopathology* / Q000635:transmission; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology* / Q000503:physiopathology*; D004926:Escherichia coli / Q000302:isolation & purification; D005192:Family Health; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D001257:Mamastrovirus / Q000302:isolation & purification; D029322:Norovirus / Q000302:isolation & purification; D011446:Prospective Studies; D012401:Rotavirus / Q000302:isolation & purification; D029341:Sapovirus / Q000302:isolation & purification; D014481:United States / Q000453:epidemiology