A highly drug-resistant strain of cholera has been found in patients around the world, according to a new report in the New England Journal of Medicine. The World Health Organization has estimated that there are between 1.3 and 4 million cases of cholera worldwide every year, and there are anywhere from 21,000 to 143,000 deaths annually due to the illness. But cases have also been rising in recent years.
This study has shown that a particular strain of cholera that is resistant to ten different antibiotics, which include two common cholera treatments called azithromycin and ciprofloxacin, appeared during an outbreak in Yemen that happened in 2018 and 2019. The spread of this strain was tracked using genomic tools. And the pathogen was found to have also sickened people in Lebanon in 2022; Kenya in 2023; and Tanzania and the Comoros Islands, which are off the coast of Africa, in 2024. Mayotte, which is an island in Comoros, experienced a cholera outbreak due to this strain, which sickened 224 people in 2024 as well.
Cholera causes severe, watery diarrhea, and the bacterial illness has been affecting people for centuries. We are currently in the midst of the seventh cholera pandemic. Some countries frequently have cholera outbreaks, while the disease has ben largely eradicated from other places. One challenge is ensuring that people have access to clean drinking water and basic sanitation, because cholera is caused by certain strains of Vibrio cholerae bacteria, which naturally live in water.
While most cases of cholera are usually mild and it tends to be an easily treatable disease that people recover from, severe forms of cholera can rapidly cause death, and some strains of Vibrio are becoming more resistant to many commonly used antibiotics.
Cholera treatment typically involves rehydration to restore water and electrolytes that are lost in diarrhea. Case fatality rates tend to be under one percent. But this study has highlighted the changing nature of the pathogen, and the need for monitoring.
"This study demonstrates the need to strengthen global surveillance of the cholera agent, and especially to determine how it reacts to antibiotics in real time. If the new strain that is currently circulating acquires additional resistance to tetracycline, this would compromise all possible oral antibiotic treatment," stressed senior study author Professor François-Xavier Weill, Head of the Vibrios CNR at the Institut Pasteur.