Over 5,000 people have been infected with the Ebola Bundibugyo virus in the Democratic Republic of Congo (DRC), but the outbreak may be three times this size, warned the Africa Centre for Disease Control and Prevention.

Africa CDC’s Prof Yap Boum said that this was the estimation of various experts and academics, as “only 30-40% of cases” were being detected.

Part of the reason is that the symptoms for Bundibugyo are milder than Ebola Zaire and “you don’t have the bleeding”, which makes it harder to distinguish from other illnesses, he added.

Boum also noted that the vast majority of deaths – 97% in the past week – were still taking place in the “community” – although he clarified that the definition included health facilities that were not Ebola treatment centres.

Once again, the Africa CDC highlighted the weakness in contact tracing, with only around 16% of contacts of those with Ebola traced.

Boum also sounded the alarm about new cases detected in the DRC provinces of Haut-Uélé and Bas-Uélé, which border the Central African Republic (CAR). Two cases have now been detected in the Bas-Uélé capital of Buta, about 200km from the CAR border.

Last week, the World Health Organization (WHO) Director-General Dr Tedros Adhanom Ghebreyesus and Africa CDC leaders met in CAR to assist the country to prepare for Ebola in case it moved across the border.

Measures include increased surveillance at checkpoints and borders, and bolstering laboratories.

This week, the International Coordinating Group on Vaccine Provision (ICG) agreed to send 70,000 doses of Ervebo vaccines to the DRC, following a government request. The ICG manages the vaccine stockpile. 

While Ervebo is licensed and recommended for use against the Zaire strain, a clinical trial is underway to assess its impact on Bundibugyo. Early laboratory and animal data suggest it may provide some protection

The allocation includes 20,000 doses for the Phase 3 of this trial, and 50,000 doses are for frontline and health workers in line with the current recommendations of the WHO Strategic Advisory Group of Experts on Immunization (SAGE).

Two other vaccine candidates, ChAdOx1, and Moderna’s mRNA vaccine, are currently recruiting patients in the DRC  for early trials.

Image Credits: John Wessels/ MSF.