Severe diarrhoea cases now top 24,500, although confirmed laboratory cases of cholera number about 1,050, with 10 deaths, the same mortality figure reported a week ago when the diarrhoea cases stood at 16,000.

“Case fatality remains very low (less than 1 per cent) which indicates good access as well as improved case management of cholera patients at all treatment centres in the affected area,” the UN World Health Organization (WHO) said.

“Provision of safe water and food, establishment of adequate sanitation services for the community at risk and implementation of personal and community hygiene constitute the main public health interventions to contain the outbreak,” it added.

The outbreak first unfolded in Kirkuk province on 14 August, spread to Sulemaniya governorate on 23 August and then to Erbil governorate on 6 September.

It is unclear what caused the outbreak, but initial investigations show some evidence that, in Sulemaniya, polluted water that residents were forced to rely on due to a shortage of drinking water may have been to blame. In Kirkuk, cracked water pipes allowed contamination by sewage, and because of the close geographic proximity the outbreak spread to Erbil.

The continuous movement of people and cargo, bad sanitary conditions and high temperatures may increase the possibility of spreading the disease rapidly to other areas such as Baghdad and the central provinces, health officials have warned.

Cholera is an acute intestinal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. It causes watery diarrhoea that can quickly lead to severe dehydration and death if treatment is not promptly given. About 80 to 90 per cent of cases are mild or moderate and are difficult to distinguish clinically from other types of acute diarrhoea. Less than 20 per cent of ill people develop typical cholera with signs of moderate or severe dehydration.