The UN health agency said in a statement that two cases were identified in Kajo Keji, a region bordering Uganda, where an outbreak of the viral hemorrhagic disease was detected early this year.

Axar.az reports that WHO warned that the risk of ongoing and further transmission of yellow fever is a concern in South Sudan due to spontaneous return of displaced persons from Uganda, gaps in surveillance and weaknesses in health services, ongoing travel restrictions imposed because of COVID-19 and the onset of the rainy season, which provides a favorable breeding ground for mosquitoes that spread the virus.

Epidemic spread of yellow fever is a risk in South Sudan as the estimated overall population immunity is negligible with nearly 0 percent immunity in Kajo Keji, WHO said.

South Sudan has experienced several yellow fever outbreaks in the past few years.