The World Health Organization (WHO) says it is investigating the deaths of nearly 100 people who succumbed to a yet to be identified disease in Fangak, Jonglei State, in South Sudan.<br />''<br />''Last week, the ministry of health reported that an unknown disease had killed dozens of people in the area which is one of the worst-hit by recent flooding. A local health official said initial samples collected in the area returned negative test results for cholera.<br />''<br />''WHO's Sheila Baya told to media that, they have decided to send a rapid response team to go and do risk assessment and investigation.<br />''<br />''She said Fangak area was not reachable by land due to flooding and the team was waiting for a helicopter to return them to the capital, Juba, on Wednesday. <br />''<br />