GENEVA - An unknown disease with fatal consequences has been reported by the Cambodia Ministry of Health, the World Health Organization (WHO) said on Wednesday.

The severe respiratory disease with neurological symptoms has to date caused 61 deaths among 62 hospitalized children.

WHO and the Health Ministry are currently conducting a joint investigation to find out the cause and source of the disease for appropriate treatment and control.

The unknown disease starts with high fever followed by respiratory and in some cases neurologic symptoms with rapid deterioration of respiratory functions.

Majority of the cases came from the southern part of the country. No apparent clustering of the cases has been observed so far.

WHO says neighboring countries have already been officially informed through a posting made through an event information system in accordance with the International Health Regulations. And all national IHR focal points have also been informed as well.

Development is under close monitoring.