Bangladesh Tuesday launched a massive drive to vaccinate Rohingya children against diphtheria after a suspected outbreak killed nine refugees and infected more than 700.
Health workers in Bangladesh said they had been caught unawares by the outbreak of the bacterial disease in the Rohingya refugee camps of southeast Bangladesh
More than 646,000 Rohingya are based in these camps, having fled violence in Myanmar in recent months.
"So far nine people have died in a suspected outbreak of diphtheria," said Meerzady Sabrina Flora, the head of Bangladesh's Institute of Epidemiology, Disease Control and Research (IEDCR).
Bangladesh's health services department said of the 700 refugees infected, 104 -- most of them children -- had contracted the disease in the last 24 hours.
Authorities have set up two isolation units in the overcrowded refugee camps, where many lack adequate shelter and food and there is little access to medical services.
Diphtheria is a highly contagious respiratory disease that can be fatal if left untreated, but has become increasingly rare in recent decades due to high rates of vaccination.
Bangladesh authorities said they had prepared for outbreaks of other diseases in the camps, but not diphtheria, which had been all but eradicated in Bangladesh.
The government and UN agencies are now vaccinating around 250,000 children under the age of seven living in camps and temporary settlements near the border with Myanmar.
"We are moving quickly to control this diphtheria outbreak before it spins out of control," said Dr Navaratnasamy Paranietharan, the World Health Organization representative to Bangladesh.
"The vaccines will help protect every Rohingya child in these temporary settlements from falling prey to the deadly disease."