As on November 4, one death and 412 suspected cases of measles have been reported among the refugees living in the overcrowded camps and makeshift shelters in Cox's Bazar in Bangladesh, the World Health Organisation (WHO) said in a statement.
Of the total cases, 352 are from Ukhia, 46 from Teknaf sub-districts and 11 have been reported from the district hospital.
Majority of the cases 398 are among the new arrivals and 14 among the host communities, the statement said, adding that as many as 82 per cent of the cases are among children under five years of age.
"To halt any wider outbreak, it's essential that coordinated efforts begin immediately to protect as many children as possible," Beigbeder said.
"These efforts are aimed at protecting and preventing the spread of measles among the vulnerable population," said N Paranietharan, WHO Representative to Bangladesh.
More than 600,000 Rohingyas have fled to Bangladesh from Myanmar after the outbreak of violence in the country's Rakhine State.