When every minute counts: Responding in the critical first 72 hours of an epidemic

MSF infectious disease specialist Diyani Dewasurendra describes the scene at a hospital receiving its first cholera cases amid a 2023 outbreak in South Sudan.

MSF staff meet before changing shifts at the cholera treatment center in Malakal, South Sudan.

An MSF team meets before the morning handover of shifts at our cholera treatment center in Assosa. During these meetings, staff share updates and data from the previous shift. | South Sudan 2024 © Paula Casado Aguirregabiria

Diyani Dewasurendra is an infectious disease specialist with Doctors Without Borders/Médecins Sans Frontières (MSF) who was working in South Sudan during a cholera outbreak in 2023. The country is currently experiencing another cholera outbreak fueled by dire water and sanitation conditions and gaps in health care and other essential services. Here, Dewasurendra describes the scene inside MSF's hospital in Malakal when the first cases started arriving, and the critical actions taken in the next 72 hours.

By Diyani Dewasurendra, MSF infectious disease specialist


Every epidemic begins with suspicion: a sudden rise in illness, recurring symptoms, and the first severely ill patients. In crisis zones, infectious diseases can spread at lightning speed. Every minute counts when trying to contain them. The first 72 hours are critical to save lives and prevent a disaster.

In 2023, I was on assignment in Malakal, South Sudan, when a cholera outbreak hit.

Hours 0 – 12: First signs and measures

At our hospital in Malakal, we suddenly saw a spike in children arriving with severe diarrhea. In a region with limited access to safe water, that’s a red flag. On top of that, it was March—the final month of the dry season. Since November, there had been almost no rainfall and many water sources had dried up. This region often sees no rain at all between November and March.

As soon as the first tests came back positive for cholera, we had to act quickly. The outbreak was now officially confirmed—and every minute counted.

We knew cholera was a possibility, but we had to be sure. We collected samples and sent them to the lab. At the same time, we began monitoring case numbers. As soon as the first tests came back positive for cholera, we had to act quickly. The outbreak was now officially confirmed—and every minute counted.

In a region where many people lack access to clean water, a disease like cholera can escalate quickly. One of the most dangerous aspects is that the only available water source is often a river—the same river where animals bathe, where people wash themselves, and from which they drink. In situations like this, contamination with germs can have catastrophic consequences.

Beds in the Assosa cholera treatment center in South Sudan.
Inside the pediatric ward at MSF's cholera treatment center in Assosa. | South Sudan 2024 © Paula Casado Aguirregabiria

Hours 48–72: Vaccination campaign and epidemic control

Now the goal was not just to slow down the outbreak, but to bring it under control. In addition to treating those already infected, the next major step was vaccination. Cholera can be contained with an oral vaccine—a major advantage, as it allows us to quickly and efficiently vaccinate large groups of people.

Before starting the vaccination campaign for the community, we had to protect our medical teams. Doctors, nurses, and support staff are in direct contact with patients, so vaccination is essential for their survival. Only after that could we begin the large-scale rollout for the affected population.

Education also played a crucial role. In crisis areas, people are not generally skeptical of vaccines—but often, they simply don’t know that a vaccine exists. As soon as we explained to the first groups the purpose and benefits of the vaccine, acceptance increased rapidly.

MSF staff taking care of a patient in a cholera treatment center.
MSF staff treat a patient in the cholera treatment center in Malakal, 200 miles south of Renk. | South Sudan 2024 © Paula Casado Aguirregabiria/MSF

Hours 24–48: Treating patients and identifying the source

While treating the first patients, we also assessed the water supply. In many parts of South Sudan, there are no wells or pumps—people collect water from rivers or ponds, which are often contaminated.

I remember one situation where cattle died en masse and hundreds of carcasses were left lying along the riverbank. Yet people had no choice but to continue drinking from the river. Many didn’t realize that the water could be dangerous.

Hundreds of carcasses were left lying along the riverbank. Yet people had no choice but to continue drinking from the river.

Together with the World Health Organization (WHO) and other partners, we tested the water quality and investigated potential sources of contamination. We knew we couldn’t just treat the disease—we had to prevent more people from getting infected. That’s why we started distributing clean water. 

In some villages, we used charcoal filters or chlorine treatment to improve the water supply in the long term. We also installed sanitation facilities like latrines.

Overview

Facts about cholera

Up to 4 million people are infected with cholera every year, and 140,000 die from it. MSF is active in the fight against cholera worldwide, treating infected patients, running vaccination campaigns, educating communities, distributing hygiene kits, and improving access to clean water and sanitation to curb future outbreaks. 

Risks and spread

Cholera is an acute bacterial infection caused by Vibrio cholerae and spreads mainly through contaminated water and food. It spreads rapidly, particularly in areas with poor water supply and sanitation. Though it occurs worldwide, the highest numbers of cases are in regions with poor water systems and sanitation. 

In humanitarian emergencies such as conflict zones or after natural hazards, the risk of outbreaks increases significantly, as people are often crowded together without access to clean water. Vaccination can significantly reduce the risk of infection and provide long-lasting protection. 

Symptoms and treatment

Cholera symptoms can appear within just a few hours or days of infection. The disease is characterized by severe watery diarrhea, which can lead to extreme dehydration, circulatory collapse, and—if left untreated—death. However, with early treatment using oral rehydration solutions or intravenous fluids, over 99 percent of patients fully recover.

In MSF medical projects, we operate specialized cholera treatment centers to care for infected patients and help stop the spread of the disease. These centers are structured to ensure isolation and safe care, and can be set up within days to respond quickly during acute emergencies.

Vaccination

The oral vaccine remains the most effective protection against cholera, and currently there is no useful alternative. Administered in two doses, the vaccine provides around 85-percent protection; during outbreaks, a single dose may be administered to protect as many people as possible quickly. The WHO recommends the vaccine for people who live in endemic areas or travel to high-risk regions.

Barriers to vaccine access

Vaccine production remains a major challenge, as demand often exceeds supply, particularly in emergencies. The global stock is kept at a level sufficient to respond to epidemics, but to not allow preventive campaigns. A limited number of manufacturers and high production costs add to the global supply shortage.

During humanitarian crises, vaccines are often not produced or delivered fast enough. Logistical hurdles, such as disrupted supply chains or lack of refrigeration, further complicate vaccination campaigns, especially in remote areas.

Affordability is also an issue. In Austria, for example, the cholera vaccine costs around $80. While prices vary by country and provider, they remain out of reach for many people worldwide.

Hours 12–24: Isolation and protection measures

The top priority is to stop the disease from spreading further. We immediately set up a cholera isolation ward at the hospital. In Malakal, this was especially challenging, as we already had a separate isolation area for measles. We had to ensure that patients with the two highly contagious diseases wouldn’t come into contact with each other, and that other patients would remain protected from infection.

Everything you need to know about cholera

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At the same time, we started prevention efforts. We installed additional handwashing stations and educated the public about the importance of hygiene. Our health promoters went into surrounding communities to explain the early symptoms of cholera and when to seek treatment. 

Cholera is a severe diarrheal illness and diseases like this are especially dangerous for small children. Though treatable, an infection can lead to death within just a few hours if left untreated.

A mother holds her child after cholera treatment in South Sudan.
Susane with her youngest child, Sunday Gabriel, who was referred to MSF's cholera treatment center, where he was diagnosed with both cholera and malaria and received treatment. | South Sudan 2024 © Paula Casado Aguirregabiria

Acting fast saves lives

The first 72 hours of an epidemic determine whether it can be contained or spirals into a disaster. In the case of the 2023 cholera outbreak, we were able to respond quickly and limit the number of cases to 1,471. After 90 days, on May 16, 2023, intervention concluded as cases had decreased significantly and the outbreak was contained.

This outbreak once again showed how crucial early diagnosis, isolation, identifying the source of infection, and fast vaccination are. Each of these steps is vital to saving lives.

We work under extremely difficult conditions in crisis zones, but access to vaccines remains one of our most powerful tool in the fight against epidemics. At the same time, we must not forget that long-term solutions—such as access to clean water—are just as important to prevent future outbreaks.

Child getting a measles vaccination in Timbuktu Mali 2020 © Mohamed Dayfour/MSF

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