Tonj South County in Warrap State OV Supervisor on Tuesday said they recorded 31 people test positive with cases of blindness caused by a fly at the river bank from January to December.
Daniel Deng Ater said they started distributing drugs to all people of the county, except pregnant women, lactating mothers less than a week and small children, Radio Don Bosco reported.
He said OV drug distributors follow four measures before giving community members drugs to avoid problems.
Mr Deng said sick people, pregnant mothers and children less than five years are not allowed to receive OV tablets because they would cause more complications.
The Supervisor advised the entire community of Tonj to protect themselves from OV diseases by getting drugs in the hospital.