The Ebola outbreak in the Democratic Republic of the Congo has reached 5,515 cases and 2,642 deaths, according to government figures reported by Al Jazeera. That is a case fatality rate of close to 48 percent, and it has been climbing.

Ituri and North Kivu remain the centers of transmission, with 51 new cases detected. Uganda, and some health zones in Ituri and South Kivu, have interrupted transmission.

The rate is the number to watch

Case counts tell you how far a disease has spread. The fatality rate tells you what happens to the people who catch it, and a rising rate is the more troubling signal of the two.

It can rise for several reasons: because the sickest patients are reaching care late or not at all, because treatment centers are overwhelmed, or because milder cases are going undetected and so never enter the denominator. Each of those is a failure of reach rather than of medicine. None of them is good news, and the source does not say which is operating here.

Vaccination is arriving slowly

The World Health Organization has pledged 70,000 doses of the Ervebo vaccine. As of August 23, some 16,250 had arrived in the DRC.

There is an important qualification on those doses. Ervebo is licensed against Ebola, and, as the report puts it, "early data from animal trials suggest it may offer some protection against Bundibugyo". That is a careful sentence and it should stay careful: animal data suggesting possible partial protection is not the same as a vaccine known to work against the strain circulating.

The scale of the response

Tedros Adhanom Ghebreyesus, the WHO's director-general, has said the response "needs to be scaled up two to threefold". The WHO has declared the outbreak a Public Health Emergency of International Concern, its highest level of alert.

About 160 health workers have been infected and about 45 have died. In an outbreak fought largely by hand, in isolation wards and at burial sites, those losses compound: each one removes a trained person from a workforce that cannot be quickly replaced, and deters others from joining it.

The appeal from Rome

Speaking at the Vatican on Sunday, Pope Leo said: "I urge the international community to respond in a way that also involves local communities in prevention efforts."

The second half of that sentence is the substantive part. Ebola responses in eastern Congo have repeatedly run into local distrust, and burial and containment measures imposed from outside have met resistance before. An appeal that names community involvement as the mechanism is addressing the specific way previous efforts have failed.

What we could not establish

We could not establish when the outbreak began, which strain is circulating, how many doses have been administered as opposed to delivered, or how the government figures are compiled. We verified this account from a single publication.