A global humanitarian aid group reports 58 new cases of Ebola in the Democratic Republic of Congo last week -- the highest weekly number this year.
The International Rescue Committee says the real number may be higher.
'With mistrust and security issues, cases are likely to be going unreported,' the IRC said Sunday.
The IRC says the number of confirmed and suspected Ebola cases since the latest DRC outbreak began in August exceeds 1,000 and says it could last as long as another year.
The agency says seven months into the outbreak, the number of cases should be going down, not up.
'These numbers show that despite the hard work being done, this outbreak is far from over. Insecurity and violence has led to the IRC and other agencies being forced to frequently suspend programs, which time and again we have seen lead to a spike in cases,' the agency said.
The IRC said it and other agencies have to work even harder to overcome the mistrust and misunderstanding that dogs health workers in many communities.
Ebola is a rare but potentially deadly disease caused by a virus believed to have originated in monkeys. It can cause severe bleeding and organ failure. It is generally spread by contact with the bodily fluids of victims.