Prevalence of Helicobacter pylori infection in Kenyan schoolchildren aged 3-15 years and risk factors for infection.

OBJECTIVES: To determine the prevalence of Helicobacter pylori (Hp) infection in Kenyan schoolchildren aged 3-15 years and the risk factors for infection.

DESIGN: A cross-sectional survey and study of risk factors.

SUBJECTS: Primary-school children in Trans Nzoia district, Kenya.

METHODS: Hp status was determined using the 13C-urea breath test. Risk factors were assessed using a structured interview schedule.

RESULTS: Of 205 children interviewed, valid breath test results were obtained for 192 (93.7%), of whom 155 (80.7% (95% CI 75.2-86.3)) were infected. Univariate analysis showed weak associations between Hp infection and rural areas (location of home, Relative Risk (RR)= 1.2 (1.0-1.4); location of school, RR = 1.2 (1.0-1.3)) and lower socio-economic status (RR = 1.2 (1.0-1.4)). Access to only a pit-latrine in the home (RR = 1.2 (1.0-1.4)) and plate-sharing with other family members in the home also increased the likelihood of Hp infection (RR = 1.3 (1.1 -1.6)). However, after logistic regression modelling only plate-sharing in the home remained as an independent risk factor (odds ratio (OR) = 2.8 (1.3-6.3)).

CONCLUSIONS: The prevalence of Hp infection in Kenyan schoolchildren aged 3-15 years is already high, suggesting that most acquisition occurs before age 3 years. Children who normally shared a plate with other family members during meals in the home had a higher prevalence of infection, suggesting that oro-oral transmission may be important in this population. Future studies in developing countries should focus on younger children (before age 3 years), and consider the possibility of adult-child, oro-oral transmission in order to establish likely modes of transmission.