Protective Immunity to Human Cholera in Bangladesh
Condition: Cholera
MeSH terms: Cholera
Study type: Observational

Summary: 
      The purpose of this study is to better understand how the body fights and protects against
      cholera. Two hundered fifty people presenting to the International Centre for Diarrhoeal
      Diseases Research, Bangladesh, admitted with acute cholera, 50 of whom (healthy, nonpregnant,
      18-45 year olds) will be enrolled in this substudy of mucosal immunity involving duodenal
      biopsy. The remainder of the study is observational, involving collection of stool, vomit,
      and blood samples only. The biopsy requires a flexible tube with a camera be inserted through
      the mouth into the stomach and intestine. During this procedure, small samples will be
      collected from the intestine. The study includes medical history, physical, blood testing,
      hospitalization and urine pregnancy testing. This study will last for 5 years and patients
      will participate for 3 years.
    

Detailed description: 
      Diarrheal diseases are some of the most common causes of morbidity and mortality in the world
      today. Unfortunately, effective vaccines for most of the infectious causes of diarrhea are
      not yet available. Vibrio cholerae (V cholerae) is an important infectious cause of severe
      secretory diarrhea in humans. The purpose of this study is to assess the duration of immune
      responses in a group of 250 individuals, aged 2-60 years, presenting to the International
      Centre for Diarrheal Diseases Research, Bangladesh (ICDDR,B) hospital who are admitted with
      acute cholera. Fifty of these participants will be enrolled in a substudy of mucosal immunity
      involving duodenal biopsy. This protocol focuses exclusively on the subset of 50 study
      participants (healthy 18-45 year old non pregnant subjects) enrolled in the substudy of
      mucosal immunity involving duodenal biopsy. This study is linked to DMID protocol 06-0045.
      The remainder of the study is observational, involving collection of stool, vomit, and blood
      samples only (DMID protocol 06-0045). A duodenal biopsy will be performed on enrollment or
      the next day and at Day 30. Twenty five subjects will undergo a third duodenal biopsy after 6
      months of follow-up and 25 subjects will undergo a third duodenal biopsy after 12 months
      follow-up. The objectives of this study are as follows: to measure immune responses directed
      against Vibrio cholerae antigens and evaluate the development of anti-V cholerae memory B
      cells in study participants with cholera; to assess the duration of the immune responses
      following an episode of cholera; and to correlate the duration of antigen-specific,
      antibody-secreting cells for various cholera antigens in duodenal tissue with measurements of
      the duration of immunity based on antibody responses in serum, as well as circulating
      antigen-specific memory B cells. This is a single site study with a 5 year duration requiring
      three years of patient participation.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        18 males and nonpregnant females, without comorbid conditions, ranging from 18 to 45 years
        of age, inclusive, who are admitted to the International Centre for Diarrhoeal Research,
        Bangladesh (ICDDR,B) with acute cholera.
      
Biospecimen description: 
      Duodenal biopsy samples and blood.
    
Keywords: Vibrio cholerae, Cholera, Bangladesh, esophagogastroduodenoscopy, sub-study