UT-Houston Infectious Diseases Expert Leads Travelers' Diarrhea Study in Mexico

Dr. Herbert L. DuPont, Mary W. Kelsey Professor of Medical Sciences at The University of Texas-Houston Health Science Center, wants to take the fear out of the adage, "don't drink the water" once and for all.

Dr. DuPont and colleagues Dr. Charles D. Ericsson, professor and head of clinical infectious diseases and director of the Travel Medicine Clinic at UT-Houston Medical School, and Dr. Zhi-Dong Jiang, assistant professor of biological sciences at UT-Houston School of Public Health, will study the antibiotic Rifaximin as part of UT-Houston's Travelers' Diarrhea Research Program.

The researchers and students from the two UT-Houston schools will escape to sunny Guadalajara, Mexico, this summer. For two months, the research team will test the latest in medications for travelers' diarrhea while the students gain a unique learning experience outside the classroom.

While in Guadalajara, Dr. Jiang will also conduct a study to determine why some people develop diarrhea and others do not. Dr. Ericsson will also look at the role diet plays in recovery from diarrhea.

Travelers' diarrhea is commonly caused by food and water contaminated with bacteria such as E. coli. Less frequently, parasites or viruses found in water can trigger the disease. Symptoms include nausea, stomach pain and vomiting. In severe cases, the diarrhea can lead to high fever and passage of bloody stools.

The multi-center program is based at the Universidad Autonoma de Guadalajara (UAG) and involves students studying Spanish and Mexican culture from UAG, the University of San Diego and the University of Arizona. The students will travel to Guadalajara where they will sharpen their Spanish while serving as study participants.

In the treatment study, students with diarrhea will be divided into two groups: a treatment group and a placebo group. To study how susceptible people are to diarrhea, the researchers will follow the students to see if they become ill and obtain blood, saliva and stool samples.

In a previous study, the UT-Houston research team proved that antibiotics called fluoroquinolones helped prevent or treat travelers' diarrhea with few side effects.

"Antibacterial drugs like quinolones can prevent 90 percent of diarrhea if taken once a day. These drugs can shorten the course of diarrhea from 100 hours to less than 24 hours," says Dr. DuPont, who is also chief of internal medicine at St. Luke's Episcopal Hospital. "Most travelers should use antibiotics for therapy and not prevention."

This summer marks Dr. DuPont's 26th consecutive annual research mission to Mexico and the 21st consecutive year that senior medical students have taken part in the mission. In 1975, UT-Houston Medical School organized its first clinic at The Universidad de las Americas in Cholula, Mexico. He says that very little has changed since then.

"The rate of diarrhea is as high today as it was in 1975," says Dr. DuPont.

A major focus of the program is to answer important questions related to the causes, treatment and prevention of travelers' diarrhea. So far, Dr. DuPont says, the program has answered several key questions linked to diarrhea.

"Our program has established the role food and water play in disease transmission in travelers' diarrhea and has shown that people develop immunity through repeated exposures to prevalent agents," says Dr. DuPont.

Water is the main culprit that stores viral pathogens, including rotaviruses commonly found in Mexico's tap water.

Dr. DuPont reminds people traveling to developing countries like Mexico to choose thoroughly and freshly cooked foods like soups, vegetables, meat and seafood served steaming hot and bottled beverages without ice. For travelers highly prone to travelers' diarrhea, Pepto-Bismol® should be taken regularly with meals and at bedtime, which can reduce by as much as 65 percent the risk of contracting diarrhea.

Dr. DuPont says diarrhea in Mexican infants and children mimics travelers' diarrhea in adults. He hopes the team's findings this summer will lead to a cure.

"If we can find a cure or a vaccine for travelers, we will also help attack diarrhea in children living in developing countries like Mexico who suffer the greatest consequence of the illness," says Dr. DuPont.

UT-Houston's Travelers' Diarrhea Research Program has virtually written the textbook on travelers' diarrhea. Studies under the program have led to the development of the latest guidelines for therapy and prevention of the disease.

The program in infectious diseases and clinical microbiology at UT-Houston was established in 1973, housing the first lab of its kind in the world to study the known causes of diarrhea.

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©2006 Texas Medical Center

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