Diarrhea etiology in a pediatric emergency department: a case control study.
BACKGROUND
The etiology of childhood diarrhea is frequently unknown.


METHODS
We sought Aeromonas, Campylobacter, Escherichia coli O157:H7, Pleisiomonas shigelloides, Salmonella, Shigella, Vibrio, and Yersinia (by culture), adenoviruses, astroviruses, noroviruses, rotavirus, and Shiga toxin-producing E. coli (STEC; by enzyme immunoassay), Clostridium difficile (by cytotoxicity), parasites (by microscopy), and enteroaggregative E. coli (EAEC; by polymerase chain reaction [PCR] analysis) in the stools of 254 children with diarrhea presenting to a pediatric emergency facility. Age- and geographic-matched community controls without diarrhea (n = 452) were similarly studied, except bacterial cultures of the stool were limited only to cases.


RESULTS
Twenty-nine (11.4%) case stools contained 13 Salmonella, 10 STEC (6 O157:H7 and 4 non-O157:H7 serotypes), 5 Campylobacter, and 2 Shigella. PCR-defined EAEC were present more often in case (3.2%) specimens than in control (0.9%) specimens (adjusted odds ratio [OR], 3.9; 95% confidence interval [CI], 1.1-13.7), and their adherence phenotypes were variable. Rotavirus, astrovirus, and adenovirus were more common among cases than controls, but both groups contained noroviruses and C. difficile at similar rates. PCR evidence of hypervirulent C. difficile was found in case and control stools; parasites were much more common in control specimens.


CONCLUSIONS
EAEC are associated with childhood diarrhea in Seattle, but the optimal way to identify these agents warrants determination. Children without diarrhea harbor diarrheagenic pathogens, including hypervirulent C. difficile. Our data support the importance of taking into account host susceptibility, microbial density, and organism virulence traits in future case-control studies, not merely categorizing candidate pathogens as being present or absent.
Department of Pediatrics, Washington University School of Medicine, St Louis, MO, USA.
Donna M
DM
Denno
Nurmohammad
N
Shaikh
Jenny R
JR
Stapp
Xuan
X
Qin
Carolyn M
CM
Hutter
Valerie
V
Hoffman
Jody C
JC
Mooney
Kelly M
KM
Wood
Harold J
HJ
Stevens
Robert
R
Jones
Phillip I
PI
Tarr
Eileen J
EJ
Klein
D001424:Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D016022:Case-Control Studies; D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology* / Q000209:etiology*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005243:Feces / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010272:Parasitic Diseases / Q000453:epidemiology* / Q000469:parasitology; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D014777:Virus Diseases / Q000453:epidemiology* / Q000821:virology; D014861:Washington / Q000453:epidemiology