Parveen Garg, BA¹, Sharon Perry, PhD², Maria de Luz Sanchez, BA³, and Julie Parsonnet, MD³. (1) Medicine, Northwestern University, 3315 Kimberly Way, San Mateo, CA 94403, 312-285-3791, parveen@md.northwestern.edu, (2) Division of Geographic Medicine and Infectious Diseases, Stanford University School of Medicine, HRP (Redwood) Building, Room T225, Mail code 5405, Stanford, CA 94305, (3) Infectious Diseases, Stanford University, 300 Pasteur Drive, Grant Bldg, S131, Stanford, CA 94305

Background: Sources of person-to-person transmission of H. pylori have been difficult to delineate in part because the structure of high risk households is often complex. We examined concordance of H. pylori infection among Latino children residing in extended family households in Bay Area communities. Methods: Households participating in an ongoing prospective study of H. pylori transmission were interviewed regarding family affiliation; individuals >=2 years of age had serologic testing for H. pylori infection. Households with at least two nuclear families and at least one child per family were included. Logistic regression was used to assess concordance of H. pylori infection in children aged 2-18 years adjusting for family affiliation, age, household size and sleeping density. Results: 230 children resided in 63 households with 144 nuclear families; 94 children were members of the index family, 112 children belonged to families related to the index family, and 24 were in unrelated families (median household size: 9 residents, 5 children and 4 adults). Seroprevalence of H. pylori was 24% among children and 61% among adults. Residing with at least one infected sibling or nonsibling was associated with H. pylori infection [AOR: 5.9 (95% CI: 2.6-13) and AOR: 2.0([95% CI: 1.0-4.2), p=.06, respectively]. Conclusion: Siblings have greater concordance of H. pylori infection than do non-sibling children living within the same household. Although potential confounders such as duration of cohabitation could not be assessed, the data suggest either that closer contact within nuclear families or genetic factors could play a role in H. pylori transmission.

Learning Objectives:

• Evaluate methods of a large community-based prospective study of H. pylori transmission
• Recognize the complex cultural structure of households at risk of H. pylori and other gastrointestional infections
• Distinguish sources of person-to-person transmission of infection (community, household, familial)
• Apply these concepts to inquiries regarding a communicable infection (H. pylori) for which transmission mode is unknown

Keywords: Helicobactor pylori, Epidemiology

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.