The United Nations says there are now over 200,000 suspected cholera cases in Yemen with a joint statement from the World Health Organisation and UNICEF saying the country was now facing the worst cholera outbreak anywhere in the world.
The agencies said they are doing everything they can to stop Yemen's cholera outbreak from accelerating by tracking the spread of the disease.
They have also deployed rapid response teams to go from house to house telling people how to protect themselves by cleaning and storing drinking water.
But two years of civil war have destroyed health services and sanitation systems in Yemen.
Severe food shortages have led to widespread malnutrition which makes people, particularly children, more vulnerable to disease.
So far more than 1,300 people have died - one quarter of them children - with the death toll expected to rise.
Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholera.
Most of those infected will have no or mild symptoms but, in severe cases, the disease can kill within hours if left untreated.
The war has left 18.8 million of Yemen's 28 million people needing humanitarian assistance and almost seven million on the brink of famine.