Cholera is a deadly diarrheal disease that continues to threaten millions worldwide, with up to 4 million cases and as many as 143,000 deaths each year. In Bangladesh alone, where cholera is a persistent danger, 66 million people are at risk, with more than 100,000 cases and 4,500 deaths annually.

Vibrio cholerae, is evolving in ways that make the disease more severe and harder to control, but until now, scientists have struggled to pinpoint the exact genetic factors driving these changes.

There is even less knowledge about the genomic traits responsible for the severity of cholera resulting from these lineages. About 1 in 5 people with cholera will experience a severe condition owing to a combination of symptoms (primarily diarrhea, vomiting, and dehydration).