Risk factors for shigellosis in Thailand

Objectives: To assess the potential risk factors for shigellosis including housefly density. Methods: A matched case-control study to investigate potential risk factors for shigellosis was conducted in a semi-urban area, Kaengkhoi District, Saraburi Province, central Thailand. Shigello cases were ascertained from a two-year population-based surveillance study detecting diarrhea and shigellosis in the area. The study evaluated a wide range of exposures, which were assessed by odds ratios (OR) adjusted for proxy markers of socioeconomic status: family income, and type of residence, using conditional logistic regression analysis. Results: Hygiene behaviors such as regular hand washing (p < 0.05), a clean environment surrounding the household (p < 0.001), and the availability of water to flush the toilet (p = 0.08) were associated with a reduced risk for shigellosis in the multivariate model. In contrast factors indicating a tower than average socioeconomic status, such as having to rent instead of owning one's housing (p < 0.001) and a low family income (p < 0.01) were associated with an increased risk for shigellosis. For children, breastfeeding showed a strong protective effect in reducing the risk of shigellosis (p < 0.01). Prior to adjustment for environmental factors, fly density in the kitchen area was associated with an increased risk of shigellosis (p < 0.01). Conclusions: We found a correlation between socioeconomic status and the risk for shigellosis. To reduce shigellosis in this setting, we recommend interventions focused on three aspects: improved water supply and sanitation (especially latrines and garbage disposal) including fly control, health education on hand washing, and the promotion of breastfeeding. (c) 2006 International Society for Infectious Diseases. Published by Elsevier Ltd. Ail rights reserved.