An experimental skin patch developed by US biotechnology company Iomai Corp. protected more than 70 percent of visitors to Mexico and Guatemala from traveler’s diarrhoea, an illness that sickens millions each year.

People who travel to endemic areas often suffer from diarrhoea due to E-coli bacterium that is toxic to the digestive system. The patch protects against Escherichia coli bacteria, specifically a strain known as Enterotoxigenic E. coli or ETEC. The condition is characterized by 4 to 5 days of frequent loose stool, nausea, vomiting, abdominal cramps, prostration, and dehydration.

The company-funded study examined 170 travelers to Mexico and Guatemala. They were given either the vaccine patch or a placebo. Those given the vaccine patch were less likely to suffer from severe diarrhoea, had shorter episodes and milder symptoms than those who had a placebo.

“The LT patch vaccine conferred some protective efficacy against moderate-to-severe travellers’ diarrhoea of any cause, severe diarrhoea, and moderate-to-severe ETEC diarrhoea. Furthermore, recipients of the LT patch who became ill had a milder course of illness, with reduced stool output and duration of diarrhoea illness compared with placebo. Taken together, the LT patch conferred a meaningful benefit to the recipients,” said the authors.

The study initiated by a team of researchers, led by Dr. Gregory Glenn and Dr. Sarah Frech (IOMAI Corporation, Gaithersburg, MD, USA) was published online in “The Lancet.”