It is believed that the outbreak in Kenya started from newly arriving refugees who carried the disease with them from Somalia or contracted it en route by drinking contaminated water in flooded areas.

Somalis travel across a vast and unforgiving desert for days before they can even make it into Kenya’s border and many arrive malnourished and in poor health.

Kenya’s Dadaab refugee camp is already overcrowded and heavy rains and insecurity in neighboring Somalia are hampering aid efforts at the camp.

Last month two aid workers from Medecins Sans Frontieres (MSF) were kidnapped. Kenyan officials believe the aid workers were kidnapped by Somali militant group Al Shabab.

Andrej Mahecic, a spokesman for the U.N. agency for refugees, told reporters at a news briefing, “We are talking about a very volatile situation along the border with the situation in Somalia not getting any better.”

Mahecic also expressed concerns about rain and heavy flooding that affected the trucking of water to parts of Dadaab camps saying “we fear some refugees resorted to using unsafe water from flooded areas.”

UNHCR and partner agencies have set up emergency outposts to deal with the most pressing cases of cholera.

The agency is also promoting hygiene practices among refugees and giving soap with food distributions, according to Mahecic.