Protective Immunity to Human Cholera in Bangladesh
Protective Immunity to Human Cholera in Bangladesh
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.
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.
Inclusion Criteria:

 For the esophagogastroduodenoscopy (EGD) substudy of 50 study participants

 -  Admission to the International Centre for Diarrhoeal Diseases Research, Bangladesh
 (ICDDR,B) with acute cholera

 -  Male or nonpregnant female [pregnancy will be excluded by urine human chorionic
 gonadotropin (HCG) testing]

 -  Age 18 to 45 years, inclusive

 -  Residence in Dhaka city

 -  Provision of informed consent for enrollment in study

 -  Expressed interest and availability to fulfill the study requirements

 Exclusion Criteria:

 For the esophagogastroduodenoscopy (EGD) substudy of 50 study participants

 -  Participation in any other investigational drug, device or vaccine trial at present or
 within the past 30 days

 -  Known allergy to midazolam or topical anesthetics

 -  Presence of comorbid conditions, including:

 -  heart disease

 -  pulmonary disease

 -  liver disease

 -  kidney disease

 -  bleeding disorder

 -  neurologic disorder

 -  an additional intestinal disorder

 -  pregnancy

 -  anemia (hemoglobin < 12 g/dl for males or < 11 g/dl for female)

 -  hypotension (systolic blood pressure less than or equal to 85 mm Hg or diastolic blood
 pressure less than or equal to 55 mm Hg, measured in the supine position once just
 prior to procedure)

 -  hypertension (systolic blood pressure greater than or equal to 150 mm Hg or diastolic
 blood pressure greater than or equal to 90 mm Hg, measured in the supine position once
 just prior to procedure)