About 1 in 4 Ebola cases may be going undetected in Congo, WHO says

The second-worst outbreak of Ebola ever recorded has killed more than 1,300 people in Congo and the World Health Organization says workers may not be reaching about a quarter of people affected.

Health teams have been unable to reach some areas due to attacks

An Ebola survivor works as a caregiver to babies who have the virus at a treatment centre in Butembo, Congo, in this file photo. More than 1,300 people, including children, have died in the outbreak that started last year. (Baz Ratner/Reuters)

Roughly a quarter of Ebola infections in eastern Congo may be going undetected or are found too late, a World Health Organization (WHO) expert said on Thursday.

Some 2,025 cases and 1,357 deaths have been recorded since the epidemic began in August in Congo's North Kivu and Ituri provinces, said Dr. Mike Ryan, executive director of WHO's Health Emergencies program. 

It is the second-worst outbreak of the virus on record.

Health teams have been unable to reach some areas because of violence by rebel groups.

The teams also have come under attack by locals who mistrust foreigners and government officials in a long-volatile region far from the capital.

Greater political engagement is needed to combat the Ebola outbreak, Ryan said.

"We need the government to reach out to the opposition, we need an 'all party' approach ... we need a single voice of leaders in Congo about this outbreak."

More than 85 infections have been detected each of the last two weeks, down from a peak of 126 weekly in April, and WHO teams are following up on 15,000 suspected contacts each day, a "huge number" who require checking for symptoms, he added.

A health worker wearing Ebola protection gear enters the Biosecure Emergency Care Unit at the ALIMA (Alliance for International Medical Action) Ebola treatment centre in Beni, Congo, in this file photo. (Baz Ratner/Reuters)

"Let me be very cautious here, we believe we are probably detecting in excess of 75 per cent of cases. We may be missing up to a quarter of cases," Ryan told a news briefing in Geneva.

Late detection of cases was still a problem, he added.

"We must get earlier detection of cases, have more exhaustive identification of contacts."

About 90 per cent of people potentially exposed to the virus have agreed to be vaccinated, which has proved efficient, he said.

"It's not them that matter now," Ryan said. "It's the 10 per cent that don't [agree to be vaccinated] because all of our cases are coming from that group."

The epidemic was not under control, he said, and was spreading fast in the rural area of Mabalako and at a lesser rate in the city of Butembo.

Ryan said attacks on aid workers had decreased of late but noted a deadly attack on civilians earlier this week.

A local official said 13 civilians were killed late on Monday in an attack by the Allied Democratic Forces (ADF) — a group thought to be linked to ISIS.

With files from The Associated Press