"Despite aggressive emergency interventions over the past 11 months, the outbreak has yet to be eradicated and its elimination will only be achieved with comprehensive, long-term investment in essential services," IRC said in a statement released here.
Since October last year, the epidemic has infected around 7,100 villagers displaced by two decades of fighting between the government and Lord's Resistance Army rebels in the region.
Northern Uganda is emerging from two decades of civil war and its tens of thousands of displaced inhabitants still living in camps are particularly vulnerable.
Since a fragile truce brought an end to the violence two years ago, some residents have started returning to their native villages.
Hepatitis E has a low mortality rate compared with hepatitis B and C and is spread by eating contaminated food or drinking water.