Measles outbreak has been confirmed in Wau State in Bahr El Ghazal region.
The outbreak has been attributed to population displacement in Wau town.
According to health partners, 40 new suspected measles cases were reported between December fifth and eleventh in Wau, Gogrial West in Warrap and Aweil South in Northern Bahr El Ghazal.
Children between the ages of 5 and 14 remain most affected.
An estimated 648 thousand children under age 5 are at risk of contracting measles across the country.
Since the beginning of 2016, more than 1,900 measles cases have been reported across South Sudan with at least 20 deaths.
Health partners say response activities are ongoing to stop the spread of the new outbreak in Wau.