"Does your baby have cholera?" an anxious health worker asks. The woman says no. "Then move away from here," he yells.

These are extreme conditions that require a stern tone. Sudan's eastern states, areas of relative safety in a country torn apart by war, are facing a battle of their own.

A fight to combat the spread of life-threatening illness like cholera - soaring in unsanitary conditions aggravated by heavy rains, mass displacement and crumbling infrastructure.

Inside the ward, health workers move quickly to triage incoming patients. Most of them are too weak to walk or talk.

One man collapses as he tries to walk from one room to the next. He is put in a wheelchair and moved to a room a few steps from where he fell. As soon as his helpers release him, he drops down onto a hard bed. There is no strength to sit up without support.

"This is the first time the state experiences something like this. At least in recent years, there has not been a cholera outbreak like this," Dr Ali Adam, Kassala Minister of Health, tell us in the quarantine ward.

He has granted us rare access to the facility despite the dire conditions around us.

"There is extreme pressure on the state's services. Kassala is home to three million people - a number that has nearly doubled."

Despite the despairing state of the people being treated behind him, those who can make it to this ward are the fortunate ones. With rehydration therapy and monitoring, they are very likely to survive.

The latest figures from Sudan's federal ministry of health show that cholera cases are surging.

On 26 September, 15,557 cases had been reported since late July. By yesterday that had jumped to 24,116 reported cases - a 55% increase in just two-and-a-half weeks.

Cholera-related deaths in the same reporting window are also on the rise. 681 people have died - a 34% increase from 507 deaths.

Experts and frontline responders told us these figures are still likely to be a gross underestimate.

Sudan's cholera outbreak is a growing, grim reality - fuelled by armed violence and the ongoing displacement of people to densely populated safe zones.

The country is currently experiencing the world's worst internal displacement crisis.

"The main issue in cholera is overpopulation," says Chiara Lodi, MSF Spain's Sudan country director.

"The movement from one state to another impacts the health system because it cannot absorb and impacts the infrastructure - the city or the village - because they do not have enough space for everyone and they are not built to have so many people."

Movement of critical supplies and humanitarian support has also been hampered by state bureaucracy in the wartime terrain.

"If we need to intervene in 24 hours as we normally do, it is impossible because we need to follow certain procedures," says Chiara.

Read more:
What has been happening in Sudan?
'They started killing people in the streets'
Eyewitness: 'Give me your daughter or we'll take her'

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As the chaos of this conflict continues to unfold, the millions of vulnerable people impacted by the spread of deadly diseases are falling through the cracks.

"In this kind of setting everyone is focussed and worried about a certain kind of patient and then we forget that actually the population that is most impacted by what is happening is not the people that are getting blast injuries," Chiara adds.

"It is children, mothers and elderly who have to escape and find themselves without anything in a place that is not built to cope with them and a health system that is heading to collapse."