Risk factors for diarrhea among children in an industrialized country.
BACKGROUND
Risk factors for childhood diarrhea in industrialized countries are not well characterized, although diarrhea remains an important cause of morbidity.


METHODS
We conducted a case-control study of 422 cases and 866 controls over 22 months in Denmark. We selected cases among children under 5 years of age with diarrhea. Age-matched healthy controls were selected from the background population using a population register. Parents were interviewed about possible exposures and underlying conditions. In addition, stool samples from both cases and controls were analyzed for viruses, parasites, and bacteria. We analyzed risk factors for diarrhea in general and for diarrhea of a viral, bacterial, or "unknown" etiology using logistic regression.


RESULTS
The following factors were independently associated with an increased risk of diarrhea: recent foreign travel, contact with symptomatic persons (particularly in daycare centers), hospitalization, contact with a dog with diarrhea, private daycare, consumption of products containing formula milk, unemployment and low educational status of parents, and prior diagnosis of several types of atopic diseases. In a pathogenic-specific analysis of diarrhea of bacterial (73 patients), viral (88), or "unknown" (222) etiology, the major risk factor for viral diarrhea was contact with symptomatic persons. For bacterial diarrhea, foreign travel and socioeconomic factors were the main risk factors.


CONCLUSIONS
Viral diarrhea appears to be transmitted predominantly from person to person, whereas bacterial diarrhea appears to be primarily foodborne. A substantial portion of the diarrheal episodes may be of noninfectious etiology. Limiting child-to-child transmission of disease in daycare centers may substantially reduce the disease burden.
Ethelberg
Steen
S
Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Copenhagen, Denmark. set@ssi.dk
Olesen
Bente
B
Neimann
Jacob
J
Schiellerup
Peter
P
Helms
Morten
M
Jensen
Charlotte
C
Böttiger
Blenda
B
Olsen
Katharina E P
KE
Scheutz
Flemming
F
Gerner-Smidt
Peter
P
Mølbak
Kåre
K
D000818:Animals; D000829:Animals, Domestic; D016022:Case-Control Studies; D002656:Child Day Care Centers; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology / Q000821:virology; D018562:Disease Transmission, Infectious; D005516:Food Microbiology; D006801:Humans; D012307:Risk Factors