The number of new Ebola virus cases in the ongoing outbreak in the Democratic Republic of the Congo shot up to 27 confirmed cases in the last week, triple the number of 9 confirmed cases reported between 27 November to 3 December. The recent surge in cases comes in the wake of insecurity and a series of violent attacks on Ebola workers that froze the response.

“Since the beginning of the response, there is a factor that we cannot control – the context of the intervention, including insecurity,” Michel Yao, incident manager for the World Health Oganization’s Ebola Response in the DRC said at a press conference (translated from French). “In the zones [where cases are arising], there is one particular zone, Lwemba [in Beni Health Zone], that we have not been able to access for three weeks.”

According to the latest WHO Disease Outbreak Notice, most cases in the past week have arisen from Mabalako and Beni Health Zones, where the Ebola response seems to be mobilizing again after temporarily scaling back activities in the last two weeks of November due to violence and riots in those affected areas. Some 18 cases were reported from Mabalako, and 6 cases from Beni, and the remaining 3 cases originated from Mandima and Oicha. Six of the confirmed cases were health care workers – including 5 traditional practitioners – representing a spike in the number of health care workers infected in the outbreak.

Despite the surge, WHO says that the average proportion of contacts under surveillance in the last seven days has returned to normal levels, and the investigation of alerts has also been improving. To ensure continued care, WHO has mounted a limited daily helicopter “air bridge” operation to transport epidemiologists to investigate cases, but to also primarily send vaccinators to hard-to-reach communities. Dr Yao noted that the communities had come to the Ebola responders seeking help.

They “want the intervention”, he insisted, “but around we have armed groups that prevent us from reaching these communities…We’re mobilising communities all around to come and get vaccinated in a situation where there are (health) alerts but we can’t go to investigate because access is restricted.”

On Thursday, the first Ebola vaccinators returned to the Biakato Mines Area, where three Ebola responders were killed in late November, to continue fighting the outbreak.

So far, 17 of the new cases have been linked to one individual – who reportedly presented with EVD illness for the second time within a 6-month period. According to WHO, rare cases of relapses of Ebola, in which a person who has previously recovered from EVD gets symptoms again, have been recorded. However, DRC officials are also investigating the possibility of reinfection – a scenario in which an individual who has recovered from Ebola gets infected with EVD from another person – which has never been documented before.

Previous studies have shown that Ebola survivors can develop immunity to the disease which can last for over a decade, but experts have long been concerned about the possibility of relapse or reinfection. The possibility of relapse or reinfection could indicate a need to revisit the kind of care provided to survivors, and how Ebola survivors are involved in future response activities.

Image Credits: Twitter: @DamelSoceFall.