Challenges and Progress in Tackling the Ebola Outbreak in the Democratic Republic of Congo

Inside the Uganda Virus Research Institute in Entebbe, laboratory technologist Sophia Mulei works diligently with control samples. This lab is one of the main centers for testing Ebola samples. The recent outbreak in the Democratic Republic of Congo, particularly in its northeastern region, has prompted urgent action from health officials. In response to potential Ebola cases reported in mid-April, samples were collected and initially sent to a lab in Bunia.

Jean-Jaques Muyembe, the director of DRC’s national biomedical research center, noted that the first samples were tested on April 30. Utilizing the GeneXpert machine, which automates viral DNA detection, the tests returned negative results for Ebola. Later samples also tested negative. However, further specialized testing in Kinshasa revealed a positive identification of Ebola.

The GeneXpert machine, integral to the DRC’s surveillance system, failed to detect the rare species of Ebola circulating, according to Muyembe. This oversight delayed the official declaration of an Ebola Bundibugyo outbreak until mid-May. This delay contributed significantly to the outbreak’s rapid spread, pushing the number of suspected cases to over 1,100.

The initial response has been significantly hampered by the lack of appropriate diagnostics on the ground, said Caia Dominicus, a senior advisor at the International Pandemic Preparedness Secretariat. This delay hindered timely patient isolation, crucial for preventing virus transmission.

Despite challenges, the response has improved over time. “Diagnostic capacity has improved significantly from where we were three and a half weeks ago,” reported Abdirahman Mahamud of the World Health Organization. Yet, current testing capabilities remain insufficient, with projections from the U.S. Centers for Disease Control and Prevention suggesting possible escalation to 20,000 cases by August.

A new machine, RADI-One, has enhanced testing efficiency. This device detects Bundibugyo with less training and equipment, allowing deployment in smaller clinics near outbreaks, such as Mongbwalu. Although seven labs and one mobile lab now conduct tests in northeastern DRC, concerns about testing capacity remain, emphasized by Dominicus. Additional RADI-One machines are planned, but supply challenges persist.

Logistic challenges also impact diagnostic efforts. Transporting samples becomes a bottleneck, delayed by remote locations and conflict, highlighted by Dominicus. Rapid tests, akin to COVID-style tests, could transform the situation. These tests promise quick results, enabling rapid isolation and containment of infected individuals. “The faster you detect someone’s positive, the faster you can actually isolate them,” explained Abraar Karan of Stanford University.

Rapid tests may miss some positive cases due to lower sensitivity than lab-based tests, but they could enhance the understanding of outbreak scope. Muyembe advocates for rapid tests for both living and deceased individuals to address community transmission risks during burials.

Development of Bundibugyo-specific rapid tests remains in progress. Existing tests for common Ebola species hold potential but require validation for field use. According to Tulane University microbiologist Robert Garry, new tests could be developed relatively quickly.

Ranu Dhillon, involved in the 2014 Guinea outbreak response, supports rapid test development over therapeutics, which would take longer. Scaling up both lab-based and rapid tests demands significant investment. Diagnostics, often overshadowed by vaccine focus, provide crucial data for decision-making, Dominicus stressed.

Despite Bundibugyo’s rarity, effective diagnostics could have lessened this outbreak’s impact. The delay in diagnostic capability severely hampered response efforts.