Cholera is an acute diarrheal infection that can kill within a matter of hours if untreated. Oral rehydration therapy — drinking water mixed with salts and sugar — saves lives, but some bellieve this "gold standard treatment" can be improved.
The bacterium that causes cholera, Vibrio cholerae, likes the glucose or sugar that is part of the oral rehydration solution. While glucose helps the body absorb the essential salts, it also makes the microbe produce more toxin.
But researchers at EPFL — the Swiss Federal Institute of Technology in Lausanne — say using rice starch instead of sugar with the rehydration salts could reduce bacterial toxicity by almost 75 percent. That would make the microbe less likely to infect a patient's family and friends if they are exposed to any body fluids.
Oral rehydration therapy to replace the massive amount of fluid that is lost to diarrhea and vomiting has lowered the fatality rate from cholera to less than one percent. But microbiologist Melanie Blokesch says replacing glucose with starch could make the treatment even better.
“So we’re not saying stop this treatment because it works well," she said. "But it can be [even] improved, so that not even one percent of patients might die but even less, or at least if we have an epidemic setting, the transmission occurs less because the symptoms are less severe, so you have less stool volume and less people that get infected as a consequence.”
The World Health Organization says cholera, a water-borne bacterium, infects three to five million people every year, and the severe dehydration it causes leads to as many as 120,000 deaths.
Oral rehydration therapy has made cholera survivable for the vast majority of patients, but they are mostly treated within the community and remain infectious until the diarrhea stops.
Using data from the 2010 cholera epidemic in Haiti, researchers at EPFL determined that using a rice starch-based solution could have reduced the number of cases there by 30 percent. That might have meant 375,000 cases on the island within the first 14 months of the epidemic, instead of the more than half million that were reported.
“If you use rice-based oral rehydration solution instead of the standard glucose-based oral rehydration solution, what people have observed in field studies is there is 10 percent less stool volume and 10 percent less duration of the disease,” added Blokesh.
Writing in the journal PLOS Neglected Tropical Diseases, Blokesh stressed glucose-based oral rehydration therapy should continue to be used. But she says public health officials ought to consider switching over to a rice starch-based solution, especially in cholera endemic areas.