A coordinated, multistrategy response in North Kivu and Ituri provinces has been led by the DRC MOH, supported by the WHO and more than 50 national and international partners. Preparedness measures have been implemented in bordering provinces and neighboring countries that are at risk, with prioritization of Uganda, South Sudan, and Rwanda and in close coordination with their ministries of health.

The data presented below represent information available through May 7, 2019. Data are derived from DRC MOH17 and WHO reports available online18,19 and are informed by analyses provided by the WHO.

Surveillance

Case detection and investigation activities have been gradually strengthened over time and with the evolution of the outbreak. Of more than 1000 alerts reported each day from outbreak-affected areas, 88 to 92% are investigated within the first 24 hours.20 Combined with cases detected by other mechanisms, this results in a daily average of 280 suspected cases.

The timeliness of identification of suspected cases and alerting of health authorities continues to be suboptimal. The median time from an alert of onset of illness to official report as a confirmed case of EVD is 6.0 days (interquartile range, 3.0 to 9.0). It takes time to investigate alerts, refer patients to testing sites, process and transport specimens to laboratories, and return laboratory results.

Contact Tracing

Timely identification of EVD cases in contacts of patients with EVD remains challenging. Examination of 911 patients with confirmed cases reported between January 1 and May 7, 2019, revealed that only 398 (44%) were registered as contacts before the onset of illness. These low numbers reflect the multifaceted challenges that response teams face in trying to list and identify contacts of patients who present to one or more community clinics where record-keeping is poor and in working among families and communities that are reluctant to cooperate. The challenge of finding contacts and detecting early symptoms is all the more acute in the context of insecurity and a highly mobile population often fearful of the response effort, with individuals often hiding, refusing to subject themselves to follow-up examinations, or traveling to distant homes in heavily forested areas and other destinations. Moreover, the difficulty field teams have in matching individuals from extensive contact lists probably leads to an underestimation of the proportion of cases among registered contacts. Nonetheless, most of the people with EVD who were initially deemed “nonregistered” contacts were retrospectively linked to cases or likely sites of exposure through epidemiologic investigation. Future phylogenetic studies should illuminate the transmission dynamics.

Patients who escape detection and in whom EVD subsequently develops play an important role in sustaining transmission and mitigate the broader effect of vaccination on epidemic control. As of May 7, 2019, approximately 88,000 contacts had been registered, of whom 12,777 are currently under surveillance, with follow-up rates of 79 to 84%.20

Screening

Extensive population mapping and identification of high-risk areas informed a coordinated effort to screen, on average, more than 200,000 people per day at 80 points of entry and control, including the borders with Uganda, Rwanda, and South Sudan. Of more than 55 million screenings conducted, 896 resulted in alerts. All alerts from outside the DRC have turned out to be negative to date. Of 354 people whose alerts were validated, 9 had laboratory-confirmed EVD.20 Three of these 9 people were identified while they were traveling to Goma. Since the city is connected by air to Addis Ababa, Ethiopia, and Bujumbura, Burundi, and since tens of thousands of people cross the border between Goma and Rwanda each day, Goma is a high-risk point for regional spread.21 In addition to a multisectoral protocol for the activation and deactivation of entry and exit screening at the airport, training sessions and refreshers have been provided to local screeners, including training on the use of a thermal camera (which enables rapid screening of large groups of people) at Goma Airport and the Grande Barriere border crossing.

Vaccination

Vaccination with rVSV-ZEBOV-GP began on August 8, 2018. Rapid rollout was possible because the necessary protocols, cold chain, and trained teams were available after the Equateur outbreak. The rVSV-ZEBOV-GP vaccine is designed to work in the postexposure setting. A ring strategy is used to identify contacts and contacts of contacts. In addition, high-risk groups such as health care workers are being vaccinated, and targeted geographic vaccination and pop-up vaccination are being undertaken in high-risk areas. Vaccine uptake among eligible participants is more than 90%, with 112,485 people vaccinated through May 7, 2019,17 including nearly 30,000 health care workers.18,19 This includes 4915 health care workers in Uganda and 1471 in South Sudan. The WHO has reported preliminary results that indicate efficacy of 97.5% in analyses of EVD onset 10 days or more after vaccination and 88.1% in analyses of EVD onset regardless of timing.22

As recommended by the Strategic Advisory Group of Experts (SAGE), vaccination eligibility was expanded in February to include pregnant women,23 and in April to include children over 6 months of age and lactating women,24 in light of the high attack and case fatality rates in these groups and accumulating data on safety and efficacy in other groups. Although a WHO-sponsored clinical trial conducted in Guinea in 2014–2015 provided evidence of efficacy of both the vaccine and the vaccination strategy, no data are available for these populations.25 The vaccine strategy was recently revised to take into consideration rising incidence, insecurity, and concerns over vaccine shortages.26

Laboratory Diagnosis

Laboratory capacity was established initially in the Beni, Mangina, and Butembo health zones and was subsequently expanded to include Komanda, Goma, Katwa, and Bunia. More than 37,000 samples have been tested, with about 280 samples tested per day in the 5 weeks leading up to May 7, 2019; all laboratories use GeneXpert (Cepheid) polymerase chain reaction as the diagnostic tool. Laboratory confirmation or exclusion is limited by distances between health facilities and laboratories and by institution of a curfew between 6 p.m. and 6 a.m. The INRB laboratory in Kinshasa provides whole-genome sequencing, and real-time sequencing capacity has now been established in Katwa. A total of 167 of 188 viral sequences have been reported.27 Limited genetic variation among virus isolates obtained from patients at different times and geographic locations suggests that all cases are related.2728 Strengthening laboratory capacity will allow genomic sequencing to be leveraged to support epidemiologic investigation by linking cases for which epidemiologic information is limited to ongoing chains of transmission and by identifying new chains of transmission.

Safe and Dignified Burials

Between 28 and 43% of deaths each week occur outside Ebola treatment and transit centers, in private hospitals and clinics, in community health centers, or at home. These cases pose a major transmission risk. The majority of these patients receive safe and dignified burials, which are crucial in cutting further chains of transmission. Patients who die in the 24 to 36 hours before laboratory tests are available are also given safe and dignified burials. Of 5223 alerts for safe and dignified burials received as of May 6, 2019, a total of 4150 (79.5%) were successfully managed by Red Cross, Civil Protection, and community emergency harm-reduction burial teams.20 Safe management in cases of suspected or proven EVD requires minimal handling of human remains, disinfection, and internment in a specified site, while maintaining respect for religious and cultural sensitivities.29 Oral swabs are obtained for detection of EVD. Despite the high numbers of alerts, relatively few people whose deaths triggered safe and dignified burial alerts have been confirmed to have had EVD.

Infection Prevention and Control

Concerted attempts have been made to rapidly decontaminate facilities where cases have been identified and to ensure that health care facilities and key sites (schools, public offices, and transit points) are equipped with training, infection prevention and control equipment (including personal protective equipment), and essential consumables such as chlorine, soap, and water. However, continuing nosocomial transmission (in up to 25% of cases) underscores the difficulty of implementing effective infection prevention and control. Among patients with confirmed EVD between January 1 and May 7 with a recorded history of exposure, 16% (161 patients) had visited a health center 2 to 21 days before the onset of EVD symptoms; 4% (43 patients) were health care workers. Nosocomial transmission may be accounting for higher proportions of EVD cases among children and women — vulnerable groups who must present for child and maternal health care — than it did in previous outbreaks in the DRC.1 Of 1183 confirmed or probable EVD cases through April 11, 2019, in which age and sex were recorded, 36% (426) were in women of child-bearing age (15 to 49 years) and 26% (305) were in children younger than 15 years, including 77 (7%) infants younger than 12 months.17 The high risk to health care workers is evident. The lack of systematic collection of data on pregnant women and breast-feeding mothers in addition to the lack of official statistics on total numbers of health care workers in North Kivu and Ituri provinces limits more nuanced analysis.

Case Management

Ebola treatment centers provide aggressive rehydration, correction of electrolyte imbalances, and nutritional support. This supportive care is not only a prerequisite to the use of novel therapeutics, but is also lifesaving in itself — the patient’s immune system plays a key antiviral role, and each day the patient survives improves the chance of cure. A compassionate-use protocol (Monitored Emergency Use of Unregistered and Investigational Interventions, or MEURI) is offered to all patients with laboratory-confirmed EVD.30 This protocol includes three antibody-based therapies (MAb114, ZMapp, and REGN-EB3) and one antiviral agent (Remdesivir). A randomized, controlled trial of these four investigational treatments began on November 24, 2018 (ClinicalTrials.gov number, NCT03719586); the trial was interrupted because of attacks on Ebola treatment centers in Katwa and Butembo, but it has since resumed.

Risk Communication, Community Engagement, and Social Mobilization

Distrust of government extended to the health care provided by state-sponsored facilities. This was considered to be inferior to costly private health care and traditional healers. The nonspecific clinical signs of EVD — vomiting, diarrhea, sweating, dehydration, and hypovolemic shock — together with undifferentiated symptoms of fever, headache, fatigue, and myalgia — complicate diagnosis in the context of a high burden of other febrile infectious diseases and in a population in which coexisting conditions are common. In October 2018, a concurrent wave of malaria cases in Beni increased the difficulty of diagnosis and also the number of people exposed to Ebola in overcrowded health care facilities with inadequate infection prevention and control measures. Mass distribution of malaria drugs and bed nets, organized by the WHO with the support of the Global Fund, cut malaria cases, reduced the likelihood of EVD transmission at health centers, and increased community engagement.

Efforts to encourage greater local participation in and ownership of the response are ongoing and have yielded some success in areas that were initially difficult to reach. Community dialogues involving more than 100 participants have been held in areas where tension was observed between community members and Ebola response teams. Community Ebola committees are being set up in these areas to lead Ebola surveillance and interventions such as safe and dignified burials.