This week, we provide an update to last Thursday’s post on the Ebola outbreak in the Democratic Republic of Congo. At least three major developments have occurred since the declaration of an Ebola outbreak in Equateur Province on May 8, potentially signaling a worrisome escalation of the situation. The international community has responded by deploying public health experts, distributing financial resources, and shipping an experimental Ebola vaccine to the region.

Key Trends

First, the total case count has increased significantly. As of May 15, WHO reports a total of 44 confirmed, probable, and suspected cases, including 19 deaths. This means cases have more than doubled (21 to 44) since the outbreak was declared last week. WHO also confirms that an additional specimen has tested positive for Ebola following diagnostic testing at the National Institute for Biomedical Research (INRB) in Kinshasa. As a result, a total of three cases have been confirmed by the INRB; diagnostic testing for Ebola may be ongoing in other patients. Health officials are also monitoring an additional 393 contacts for possible Ebola exposure. As we pointed out last week, overcounting of cases is not uncommon during the initial stage of the response, as investigators scramble to gather information, attempt to distinguish Ebola cases from more common diseases, and continually reclassify cases.  

Second, reports indicate that the outbreak is occurring over a larger geographic area than initially reported. Initial cases were reported in Bikoro health zone and Iboko health zone, but as of May 17, the virus has spread to three health zones within Equateur Province: Bikoro, Iboko, and Wangata. The Wangata health zone is located approximately 100 kilometers (60 miles) from the town of Bikoro, the site of the first reported cases. According to the International Organization for Migration (IOM), Equateur Province covers 100,000 square kilometers (39,000 square miles) of remote jungle and is “extremely difficult for the international community to access, with limited transportation and communications infrastructure.” As a result, the timely movement of medical personnel, supplies, and personal protective equipment into the region will require air assets, which are costly and in short supply. Equateur Province also neighbors the Republic of Congo and the Central African Republic – which all share access to the Congo River, a major waterway – underscoring the importance of screenings at border crossings to prevent the spread of cases into other countries.

Third, officials have confirmed that Ebola has spread to the city of Mbandaka, the capital of Equateur Province. The spread of Ebola from rural areas into densely populated Mbandaka – a city of 1.2 million people – marks “a new phase” for the outbreak, according to the DRC Minister of Health Oly Ilunga Kalenga. It is worth recalling that the introduction of Ebola cases into cities in West Africa in 2014 is often cited as a key driver in escalating that outbreak, demonstrating “how swiftly the virus could move once it reached urban settings and densely populated slums.” Mbandaka is also a busy port city along the Congo River, which could facilitate the spread of the virus via water transport. This will introduce a challenging new dimension to the response, requiring a concerted effort by public health officials to locate and isolate contacts in Mbandaka before they can infect others.

It is worth noting that the WHO has not released a revised timetable of when Ebola cases may have first occurred. Some reports last week indicated that the outbreak may have started as early as December or January –  allowing more time for the virus to spread across further distances – but more recent updates do not necessarily confirm this. Greater knowledge of the origins and spread of the initial cases of Ebola will be critical for understanding whether there are any systemic weaknesses in case detection and reporting and subsequent understanding of how best to control the spread of disease

Response Priorities

Given the rapidly evolving situation and high level of uncertainty, a flexible response will be key to containing the outbreak. The response at this stage has revolved principally around isolating and treating patients, strengthening surveillance and identifying contacts, and deploying vaccine countermeasures. In the past week, the response has coalesced around three main areas: 1) partnerships, 2) finances, and 3) vaccines.

First, the WHO is working with international NGOs and national and local partners to scale up and coordinate the response, focusing principally on contact tracing and “conducting a retrospective analysis of the chain of transmission.” The WHO has deployed 30 experts to the outbreak zone, and WHO Director-General Tedros Adhanom Ghebreyesus personally visited the affected town of Bikoro on May 13. Tedros will convene an emergency committee of experts on Friday to determine whether the situation might represent a Public Health Emergency of International Concern.

WHO represents only a small percentage of international capacity on the ground and is such is working with numerous in-country partners, including Médecins Sans Frontières, the World Food Programme, UNICEF, the Red Cross, the African Union CDC, and the US CDC. For example, the UN Humanitarian Air Service (UNHAS) activated an air bridge between Kinshasa to Mbandaka and Mbandaka to Bikoro, enabling transport of supplies and personnel to these remote locations. IOM, meanwhile, is monitoring flows at border crossings and mapping population movements in affected areas. The African Union activated its Emergency Operations Center in the country and mobilized an Epidemic Response Team. Leveraging the expertise and capacities of these in-country partners as well as outside experts will be critical to containing the outbreak.

Second, millions of dollars have been allocated to support a rapid Ebola response in a bid to contain the outbreak before it grows to larger – and costlier -- proportions. The WHO released $2.6 million from its Contingency Fund of Emergencies (CFE), while the UN Central Emergency Response Fund (CERF) provided an additional $2 million to help humanitarian partners in the DRC. The fact that both WHO CFE and UN CERF are both funding the DRC Ebola response – despite the different, sometimes competing aims of these funds – suggests an alignment among health and humanitarian partners in prioritizing this response. In addition, the UK has emerged as an early bilateral supporter of the response by pledging 1 million British pounds (US$1.36 million), with UK charity the Wellcome Trust committing an additional 2 million British pounds (US$2.7 million). Despite this, these contributions appear to fall short of the $18 million needs estimate requested by the WHO for three months of operation. It is worth noting that outbreak response is notoriously hampered by inadequate financing: During the 2014 Ebola outbreak in West Africa, sufficient financial resources did not materialize until about six months after the outbreak was declared.

Third, officials are launching an unprecedented Ebola vaccination campaign to help bring the outbreak under control.  The first batch of 4,000 experimental Ebola vaccines, developed by Merck, arrived in Kinshasa on Wednesday and are expected to be transported to affected areas and used for the first time over the weekend. Another 4,000 vaccines are on the way. The vaccination campaign will prioritize high-risk individuals, including health workers, as part of a ring vaccination strategy, which was shown to be protective in a cluster-randomized clinical trial in West Africa. WHO Health Emergencies Programme Director Peter Salama said he will certainly receive the vaccine before his next visit to the affected region, even though it is not formally licensed. The vaccine will need to be transported and stored in freezing temperatures to ensure its potency. Maintaining this so-called “fridge bridge” presents a logistical challenge, and it remains to be seen if the vaccine will be effective.


Several potentially concerning developments have occurred in the DRC since last week’s Ebola outbreak declaration. These include a sizable increase in the total number of cases, the spread of the virus to new geographic areas, and its entrance into the densely populated city of Mbandaka along the Congo River. While the situation is evolving rapidly amid a high level of uncertainty, national and international response partners have responded with a surge in public health expertise, emergency financing, and medical countermeasures in the form of a new Ebola vaccine. It remains to be seen whether these aggressive measures will be sufficient to stay ahead of the outbreak as it grows increasingly dangerous.

Photo: A view of the Congo River between Kinshasa and Lukolela in the Democratic Republic of Congo, which is used as a waterway for travel and trade in the region.

Photo courtesy of Ollivier Girard/CIFOR via Flickr.

Outbreak Observatory aims to collect information on challenges and solutions associated with outbreak response and share it broadly to allow others to learn from these experiences in order to improve global outbreak response capabilities