Individual and household-level risk factors for sporadic salmonellosis in children

Abstract

Objectives: To explore risk factors for sporadic salmonellosis at the individual and household level in children in tropical Darwin, where animal faeces contaminated with Salmonella is thought to be common.

Methods: A 2-year community based case-control study of children aged 0-4 years residing in Darwin and Palmerston from June 2006. Variables included behaviour, health, food, family and housing characteristics. Environmental samples were taken from houses of case and control children.

Results: Of children whose parents were contacted, 59/131 cases and 95/222 controls were included. Salmonella was isolated from 41/56 (73%) case houses and 18/29 (62%) control houses (p = 0.29). Multivariate analyses showed breastfeeding 0.16 (p = 0.02), increasing age (months) 0.89 (p = 0.00) and daily vacuuming 0.18 (p = 0.06) were protective; consuming powdered formula milk 4.88 (p = 0.02), pet ownership 4.86 (p = 0.02), oral contact with animals 7.85 (p = 0.05), recent antibiotic use 10.01 (p = 0.03) and sweeping in the presence of children 3.73 (p = 0.04) were associated with sporadic salmonellosis.

Conclusions: Salmonellosis in children under 5 years of age is associated with potentially modifiable risk factors other than food. Breastfeeding beyond 6 months, careful hygiene when preparing formula milk and around pets, frequent cleaning of infant play areas especially quick removal of animal faeces are behaviours likely to reduce childhood sporadic salmonellosis.

Keywords: Animals; Breast feeding; Case–control studies; Child; Faeces; Formula; Infant; Residence characteristics; Risk factors; Salmonella infections.