The deadly Ebola outbreak raging in the Democratic Republic of Congo currently has a case fatality rate under 25 per cent — much lower than in other recent outbreaks, a WHO update has shown.

Since the outbreak was declared in the DRC in mid-May, the World Health Organisation has recorded more than 1,000 suspected and confirmed Ebola cases in the central African country.

Among them are 10 deaths confirmed to be from Ebola and another 223 suspected of being due to the virus, according to an update posted on X by the WHO on Wednesday, but dated May 24.

One person is also confirmed to have died from Ebola in neighbouring Uganda with a further six confirmed infections in that country, the update showed.

The United Nations health agency has warned that the true spread of the virus, which is believed to have circulated under the radar for some time, is likely much wider.

The WHO update highlighted, without further explanation, that the case fatality rate to date among the suspected cases stood at 24.6 per cent, while it was 9.8 per cent among the confirmed cases.

That is significantly lower than in the previous 16 Ebola outbreaks to hit the DRC since the disease was first identified there in 1976.

Most of those epidemics were caused by the Zaire strain of Ebola — which typically has a fatality rate of 60-90 per cent and is the only variant for which there are vaccines available.

The less common Bundibugyo strain, for which there are no approved vaccines or treatments, is behind the current outbreak.

The case fatality rates in the two previous outbreaks in DRC involving that strain, in 2007 and 2012, ranged from around 30 to 50 per cent.

But the case fatality rate typically evolves and can diminish over the course of an outbreak, as cases are detected quicker and care is provided earlier, Abdi Rahman Mahamud, the WHO emergency alert and response director, explained last week.

“Early referral and early care saves lives,” he told reporters.