Dhaka: Some 225,000 of new arrivals from Myanmar into Cox's Bazar are living in new spontaneous settlements with very limited water, sanitation and hygiene (WASH) infrastructure due to an absence of planning.

The number of new Rohingya arrivals into Cox's Bazar reached 515,000 since August 25 and some 60 percent of new arrivals are children and 30 percent are children under 5 years old, says a latest UNICEF report.

In the last week, 5011 cases of diarrhoea have been reported, said Chief of Health, UNICEF Bangladesh Maya Vandenant.

Since August 25, over 300 tube wells and 3,000 latrines have been constructed to improve WASH within both the extended existing makeshift settlements and the new spontaneous settlements.

UNICEF has launched a response plan to prevent an outbreak of Acute Watery Diarrhoea and Cholera.

There is a high level of severe malnutrition amongst child refugees which exacerbates the risks associated with an outbreak of acute watery diarrhoea and cholera.

"What we are seeing is that people are exhausted and children are at risk of diseases. There are real risks of acute watery diarrhoea and cholera. We are very concerned. Therefore, we are mounting a response in the health sector," said Maya Vandenant.

Maya Vandenant said planning of the extension camps is largely absent and there is no infrastructure for good sanitation and drainage etc.

"We see that after the rains, water flushes the camps everywhere including the toilets. Additionally, the camps are now subject to high population densities. These factors increase the risk of disease outbreak and transmission."

UNICEF has launched a response plan to prevent disease outbreaks including Acute Watery Diarrhoea and Cholera.

The response plan focusses on both prevention and treatment. The children caught up in the emergency are at very high risk for diarrhoea. UNICEF is working to upscale efforts in WASH, but the task in hand is immense.

UNICEF's response focusses on the following areas - improving WASH in settlements, participation in cholera prevention initiatives, reaching communities with life-saving awareness raising and prevention messages.

UNICEF's is focusing on the immediate provision of safe water, basic sanitation and community engagement around hygiene practices.

An oral cholera vaccination campaign targeting all children over one-year-old is planned in October, and 900,000 doses of the vaccine are expected to arrive in Bangladesh on October 7.

The vaccination campaign is expected to start on October 10.