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Thursday, 8 May, 2025
HomeInfectious DiseasesBroader antibiotic use could reduce cholera cases – Utah modelling study

Broader antibiotic use could reduce cholera cases – Utah modelling study

Recent disease modelling research from the University of Utah Health suggests that for some cholera outbreaks, prescribing antibiotics more aggressively could slow or stop the spread of the disease and even reduce the likelihood of antibiotic resistance.

The disease kills thousands of people and infects hundreds of thousands every year, and cases have spiked in recent years, leaving governments with an urgent need to find the best ways to control outbreaks.

Current public health guidelines discourage treating cholera with antibiotics in all but the most severe cases, to reduce the risk that the disease will evolve resistance to the best treatments we have, but these latest findings challenge that paradigm, reports MedicalXPress.

The results, published in Bulletin of Mathematical Biology, are based on mathematical modelling and will require further research to confirm. But they represent a first step toward understanding how antibiotics could change cholera spread.

"This might be an underused opportunity for cholera control, where expanding antibiotic treatment could have population-level benefits and help control outbreaks," says Lindsay Keegan, PhD, research associate professor of epidemiology at the University of Utah Health and senior author on the study.

Putting the brakes on outbreaks

Key to the researchers’ discovery is the fact that antibiotics make people less infectious. Medication is generally reserved for people who are most severely infected because moderate cases quickly recover with rest and rehydration. But while antibiotics may not help most individuals feel better faster, they reduce the amount of time someone is infectious by a factor of 10.

“If you recover naturally from cholera, you will feel better in a day or two, but you’re still shedding cholera for up to two weeks,” said Sharia Ahmed, PhD, assistant professor of epidemiology at Emory University’s Rollins School of Public Health and co-first author on the study, who did the work as a postdoctoral researcher in Keegan’s lab.

“But if you take an antibiotic, you still feel better in about a day, and you stop releasing cholera into your environment.”

This means that treating moderate cases with antibiotics could slow outbreaks or, in some cases, stop them in their tracks. Even though a higher percentage of people with cholera would be using antibiotics, fewer people would get the disease, so that fewer antibiotics are used overall.

Cumulatively, lower antibiotic use lowers the risk that cholera evolves antibiotic resistance, which is “a big concern in the field”, Keegan says.

“Cholera is exceptionally good at evading antibiotics and developing resistance. It’s not just a theoretical problem.”

The researchers mathematically modelled the spread of cholera under a variety of conditions to see which cases could benefit from antibiotic use. The key variable is how likely someone is to spread the disease to other people, which in turn depends on factors like population density and sanitation infrastructure.

In cases where cholera spreads more rapidly, like in regions with higher population density or without reliable access to clean drinking water, treating moderate cases of cholera with antibiotics wouldn’t slow the spread enough to balance out the risks of antibiotic resistance.

But if spread is relatively slow, the researchers found, using antibiotics for moderate cases could limit spread enough that, in the long run, fewer people catch the disease and fewer people are treated with antibiotics. In some cases, they predict, antibiotic use could stop outbreaks entirely.

Cases on the rise

Figuring out better plans for managing cholera is especially urgent because outbreaks are on the rise. Cases and deaths have spiked by about a third in the past year, probably related to mass displacement and natural disasters.

“We thought it was well contained to a few specific places, and now it’s popped out again,” Ahmed says.

As the climate shifts and extreme weather events become more frequent, disruptions to infrastructure could lead to cholera outbreaks in countries that haven’t previously experienced the disease.

The researchers emphasise that further work is needed before their work could motivate changes to how governments treat cholera.

Scientists need to see whether the results hold up in more complex simulations that incorporate factors like cholera vaccines, and they need to figure out rules of thumb to quickly estimate whether or not the disease will spread slowly enough for aggressive antibiotic use to be a good call.

“The takeaway is not, ‘OK, let’s start giving people antibiotics’,” Keegan says. “This is a first step at understanding antibiotic use as a possibility for outbreak control.”

“If the results continue to be this compelling,” Ahmed added, “and we can replicate them in different settings, I think then we start talking about changing our policy for antibiotic treatment for cholera. This is a really good example of using data to continually improve our policy and our treatment choices for even well-established diseases.”

Study details

A theoretical framework to quantify the trade-off between individual and population benefits of expanded antibiotic use

Cormac LaPrete, Sharia Ahmed, Damon Toth at al.

Published in the Bulletin of Mathematical Biology on 30 April 2025

Abstract

The use of antibiotics during a disease outbreak presents a critical trade-off between immediate treatment benefits to the individual and the long-term risk to the population. Typically, the extensive use of antibiotics has been thought to increase selective pressures, leading to resistance. This study explores scenarios where expanded antibiotic treatment can be advantageous for both individual and population health. We develop a mathematical framework to assess the impacts on outbreak dynamics of choosing to treat moderate infections not treated under current guidelines, focusing on cholera as a case study. We derive conditions under which treating moderate infections can sufficiently decrease transmission and reduce the total number of antibiotic doses administered. We identify two critical thresholds: the Outbreak Prevention Threshold (OPT), where expanded treatment reduces the reproductive number below 1 and halts transmission, and the Dose Utilisation Threshold (DUT), where expanded treatment results in fewer total antibiotic doses used than under current guidelines. For cholera, we find that treating moderate infections can feasibly stop an outbreak when the untreated reproductive number is less than 1.42 and will result in fewer does used compared to current guidelines when the untreated reproductive number is less than 1.53. These findings demonstrate that conditions exist under which expanding treatment to include moderate infections can reduce disease spread and the selective pressure for antibiotic resistance. These findings extend to other pathogens and outbreak scenarios, suggesting potential targets for optimised treatment strategies that balance public health benefits and antibiotic stewardship.

 

Bulletin of Mathematical Biology article – A theoretical framework to quantify the trade-off between individual and population benefits of expanded antibiotic use (Open access)

 

MedicalXpress article – Broader antibiotic use could change the course of cholera outbreaks (Open access)

 

See more from MedicalBrief archives:

 

Desperate countries face world shortage of 50m cholera vaccines

 

Long-term strategy vital to combat cholera threat in Africa

 

Biggest threat to antibiotic resistance not script-happy GPs

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