The world's second-largest Ebola outbreak hit another milestone today, as the Democratic Republic of the Congo (DRC) recorded 2 new cases, raising outbreak totals to 500, including 289 deaths.

Of the four new deaths recorded today, two are community deaths in Beni and Mabalako, which took place outside a hospital or Ebola treatment center, raising the risk of transmission, the DRC said.

There are also 80 people currently under investigation for suspected infections, the DRC's health ministry said in its daily update.

Unknown transmission chains

According to the latest weekly update from the World Health Organization's (WHO's) African regional office, among the 500 cases are 3 healthcare workers who have been infected since Dec 1. Since August, when the outbreak began, 49 healthcare workers have been infected, and 15 of those have died.

While vaccination and case contact tracing are under way, there are still unknown transmission chains in North Kivu and Ituri provinces, the WHO said. On Dec 8, for example, the agency said five new cases were identified, yet only two of the cases were known contacts.

"Contact tracing is still of concern due to insecurity and continuing pockets of community resistance. The number of contacts being followed as of 8 December 2018 was 6,417, of whom 5,812 had been seen in the previous 24 hours, representing 92%," the WHO regional office said.

As of today, the DRC said 44,447 people have been vaccinated with Merck's unlicensed Ebola vaccine. The WHO said the remaining stock of vaccine in Beni is 4,290 doses.

Katwa hospital burned

The WHO said Beni, Katwa and Kalunguta are the hot spots of the outbreak, representing 30%, 27%, and 17% of the 119 confirmed and probable cases reported from Nov 18 to Dec 8.

The WHO also said Komanda is an area of concern owing to surveillance challenges. The organization also said two healthcare posts and the Hope Health Centre in Katwa were burned by community members, another example of ongoing resistance in the volatile region.

"Particular challenges lie in investigating new confirmed cases without clear epidemiological links to other cases, the need to strengthen contact monitoring in Beni and Komanda and the need to intensify community engagement in Katwa. In addition, the potential implication of the upcoming elections bringing large numbers of people together remains an issue," the WHO said.

Difficulties with containment

On Twitter today, Peter Salama, MD, the WHO's deputy director-general for emergency preparedness and response, said new epidemiologic data illustrate the challenges of containing the outbreak.

"The epidemiological curve shows 2 phases. First centered in Mangina, largely controlled in a month. Second wave, more concerning, dispersed across many areas, has continued for over 2 months, with about 5 new cases per day," Salama tweeted.

In Beni, which has had more than 200 cases of Ebola, Salama said, "[the] epi curve shows weekly incidence declining, but not over." As cases in Beni fall, case counts are on the rise in Katwa and Butembo.

"We continually adapt our strategies to respond to each new challenge in this complex outbreak. Working with [the DRC ministry of health], partners, we will end this," Salama said.

See also

Dec 11 DRC update

Dec 11 WHO regional report

Peter Salama Twitter posts