A case-control study of the epidemiology of sporadic Salmonella infection in infants.
OBJECTIVE
Rates of Salmonella infection are highest in infants, but little is known about potential sources of infection in this high-risk population. We performed a case-control study to identify dietary and environmental risk factors for sporadic salmonellosis among infants.


METHODS
In 2002-2004, the Foodborne Diseases Active Surveillance Network conducted a population-based, case-control study of sporadic salmonellosis among infants <1 year of age in 8 states. Cases were identified via active laboratory-based surveillance. Healthy controls were frequency matched by age and identified through birth registries or published birth announcements. We assessed diet and environmental exposures in the 5 days before illness onset or interview. Data were analyzed by using logistic regression adjusting for age.


RESULTS
The study enrolled 442 subjects and 928 controls. Compared with healthy controls, infants with Salmonella infection were less likely to have been breastfed and more likely to have had exposure to reptiles, to have ridden in a shopping cart next to meat or poultry, or to have consumed concentrated liquid infant formula during the 5-day exposure period. Travel outside the United States was associated with illness in infants 3 to 6 and >6 months of age. Attending day care with a child with diarrhea was associated with salmonellosis in infants >6 months of age.


CONCLUSIONS
We identified a number of modifiable protective and risk factors for salmonellosis in infants. Attention should be directed at developing effective preventive measures for this high-risk population.
Jones
Timothy F
TF
Communicable and Environmental Disease Services, Tennessee Department of Health, 4th Floor, Cordell Hull Building, 425 5th Ave N, Nashville, TN 37247, USA. tim.f.jones@state.tn.us
Ingram
L Amanda
LA
Fullerton
Kathleen E
KE
Marcus
Ruthanne
R
Anderson
Bridget J
BJ
McCarthy
Patrick V
PV
Vugia
Duc
D
Shiferaw
Beletshachew
B
Haubert
Nicole
N
Wedel
Stephanie
S
Angulo
Frederick J
FJ
D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012307:Risk Factors; D012480:Salmonella Infections / Q000453:epidemiology*