The Esophageal String Test as a Diagnostic Screening Tool for Eosinophilic Esophagitis Among Africans With Dysphagia in Mali and the United States

Background: Eosinophilic esophagitis (EoE) is a disease that causes inflammation in the esophagus. The esophagus is the tube that moves food from the mouth to the stomach. Diagnosing EoE currently requires a specialized tool called an endoscope. The esophageal string test (EST) is another test; the EST collects fluid from the upper digestive tract. An EST is simpler and cheaper than an endoscopy. Researchers want to know if an EST can diagnose EoE. Objective: To test if the EST can diagnose EoE in people who have trouble swallowing. Eligibility: Adults aged 18 to 65 years with trouble swallowing. They must have been born in the African continent or their parents were born in Africa. Design: Participants will be screened. They will give blood, stool, urine, and skin swab samples. They will complete surveys about their medical history, diet, symptoms, and home environment. They will bring a sample of their drinking water for testing. Participants will have an EST. They will swallow a pill capsule that contains a nylon string. One end of the string will be taped to their cheek. The string will unravel down the esophagus and into the stomach. It will be pulled out after 1 hour. Fluids that soaked into the string will be tested. At a different visit, participants will have an endoscopic exam. An endoscope is a flexible tube that is inserted down the mouth; it can be used to take tissue samples from the esophagus, stomach, and small intestine. Participants will have a final visit in person, online, or by phone. They will take a survey and talk about their test results.

NCT Number	NCT07027826
Lead Sponsor	National Institute of Allergy and Infectious Diseases (NIAID)
Conditions	Dysphagia, Eosinophilic Esophagitis
Enrollment	70 participants
Start Date	2026-08-19
Primary Completion	2027-08-31 (estimated)
Study Completion	2027-08-31 (estimated)
Updated on ClinicalTrials.gov	2026-08-14