Epidemiology of H. Pylori Transmission

Epidemiology of H. Pylori Transmission and Immunoepidemiology of Concomitant Infections

This observational epidemiologic study with nested cross-sectional and longitudinal aims will evaluate host immune response to mixed chronic infections (Helicobacter pylori, latent tuberculosis, intestinal helminthiasis) in recent US immigrants.

Study Overview

• Status: Completed
• Conditions: Communicable Diseases

Detailed Description

1750 clinically-well, adult (age 18-55 years), recent immigrants (<2 years U.S. residence), referred through cooperating public health clinics in the Santa Clara Valley area, CA will be screened for H. pylori, helminth, and latent tuberculosis infections ["Screening" population]. Of these 1750, 426 will be selected for more intensive study (Cohort population), 105 of whom will receive baseline endoscopy. Of those selected for the cohort, 300 are expected to complete a 9-month follow-up assessment, 75 of whom are expected to undergo a second follow-up endoscopy.

• Study Type: Observational
• Enrollment (Actual): 1750

Contacts and Locations

Study Locations

• United States
  • California
    • San Jose, California, United States, 95122
      • Santa Clara Public Health Clinics
    • Stanford, California, United States, 94305
      • Stanford University School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

1750 clinically-well, adult (age 18-55 years), recent immigrants (<2 years U.S. residence), referred through cooperating public health clinics in the Santa Clara Valley area, CA will be screened for H. pylori, helminth, and latent tuberculosis infections ["Screening" population]. Of these 1750, 426 will be selected for more intensive study (Cohort population), 105 of whom will receive baseline endoscopy. Of those selected for the cohort, 300 are expected to complete a 9-month follow-up assessment, 75 of whom are expected to undergo a second follow-up endoscopy.

Description

Inclusion Criteria:

• Between 18-55 years of age
• Either sex
• If female not pregnant or breastfeeding
• Lived in the United States less than 2 years
• Healthy
• Scheduled for Tuberculosis Skin Test (TST)

Exclusion Criteria:

• Under 18 and older than 55 years of age,
• Pregnant or breastfeeding
• Have lived in Unites States more that 2 years
• Chronic illness
• Not planning to get a TST

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in cytokine responses from baseline at 9 months in TB and H. pylori antigen-induced PBMC before and after provider managed treatment of latent TB or helminth infection	Baseline and 9 months after treatment for either latent TB or helminth infections; analyzed after all subjects recruited (3 years of recruitment plus 9 months follow-up).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation of cytokine response to TB antigens and helminths with humoral responses to infections with H. pylori.		Assays performed when collected over three years from recruited subjects; analyzed at the end of three years.
Population prevalence of individual and joint infections with H pylori, latent tuberculosis, heminthiasis in recent immigrant to northern California	We compare prevalence of these infections in recent immigrants by geographic area	Assays performed when collected over three years from recruited subjects; analyzed at the end of three years.

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: Santa Clara Valley Health & Hospital System

Publications and helpful links

General Publications

• Chang AH, Perry S, Du JN, Agunbiade A, Polesky A, Parsonnet J. Decreasing intestinal parasites in recent Northern California refugees. Am J Trop Med Hyg. 2013 Jan;88(1):191-7. doi: 10.4269/ajtmh.2012.12-0349. Epub 2012 Nov 13.
• Perry S, Chang AH, Sanchez L, Yang S, Haggerty TD, Parsonnet J. The immune response to tuberculosis infection in the setting of Helicobacter pylori and helminth infections. Epidemiol Infect. 2013 Jun;141(6):1232-43. doi: 10.1017/S0950268812001823. Epub 2012 Sep 7.
• Herrera V, Perry S, Parsonnet J, Banaei N. Clinical application and limitations of interferon-gamma release assays for the diagnosis of latent tuberculosis infection. Clin Infect Dis. 2011 Apr 15;52(8):1031-7. doi: 10.1093/cid/cir068.
• Perry S, Hussain R, Parsonnet J. The impact of mucosal infections on acquisition and progression of tuberculosis. Mucosal Immunol. 2011 May;4(3):246-51. doi: 10.1038/mi.2011.11. Epub 2011 Mar 16.

Study record dates

Study Major Dates

• Study Start: June 1, 2008
• Primary Completion (Actual): June 1, 2011
• Study Completion (Actual): July 1, 2013

Study Registration Dates

• First Submitted: September 1, 2011
• First Submitted That Met QC Criteria: April 14, 2016
• First Posted (Estimate): April 15, 2016

Study Record Updates

• Last Update Posted (Estimate): April 15, 2016
• Last Update Submitted That Met QC Criteria: April 14, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: chronic coinfection
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Infections; Communicable Diseases
• Other Study ID Numbers: SU-10182007-743