CDC Releases MMWRs on Ebola Outbreak in DRC and Uganda, U.S. Risk Assessment, and Modeling Scenarios

Press Conference Overview

CDC held a briefing featuring Dr. Satish Pillai, Incident Manager for CDC's Ebola response, and Dr. Jason Asher, Director of the Center for Forecasting and Outbreak Analytics. They discussed three new MMWR reports: one on the current situation in the Democratic Republic of the Congo (DRC) and Uganda, one on the U.S. risk assessment, and one on outbreak modeling scenarios.

Current Outbreak Situation

Dr. Satish K. Pillai emphasized that communities in conflict-affected regions of DRC and Uganda face an active Ebola outbreak under extraordinarily difficult conditions, including strained health infrastructure and barriers to care. This marks the 17th Ebola outbreak in DRC. CDC staff are collaborating with local public health officials to provide resources and support.

Reports Released

  1. Outbreak Situation: A Notes from the Field report documents an outbreak first detected among healthcare workers that has grown into the largest Bundibugyo virus outbreak on record. It highlights the need for sustained resources and attention.
  2. U.S. Risk Assessment: CDC’s dedicated risk assessment finds the overall risk to the general U.S. public is currently low. Entry restrictions and public health screening are enforced at four U.S. airports. No changes in daily behavior are recommended. With no approved vaccines or treatments for Bundibugyo virus, preparedness relies on screening, surveillance, and infection control.
  3. Modeling Scenarios: A modeling analysis examines possible outbreak trajectories under varying assumptions. Scenarios combine assumed death counts (50, 100, or 200) with case isolation levels (20%, 50%, 70%, or 95%) to project cases and deaths over three months.

Key Modeling Findings

  • If only 20% of cases isolate within two days of symptom onset, more than 20,000 cases are projected in two-thirds of simulations.
  • If 70% of cases isolate within two days, there is a 94% probability of limiting the outbreak to fewer than 10,000 cases.

These results underscore the critical importance of rapid case identification, isolation, and robust public health interventions to prevent an outbreak on the scale of West Africa 2014–2016.

U.S. Preparedness Measures

CDC can confirm an Ebola diagnosis within hours through its Laboratory Response Network spanning 41 states. The agency provides clinical guidance, training, and strict infection prevention protocols for U.S. hospitals. Rapid response teams are ready to deploy within 24 hours to support case management, contact tracing, monitoring, and quarantine.

Q&A Highlights

  • Public Health Measures on the Ground: Conditions remain fluid, but case detection and isolation rates are believed to be at the lower end of the modeled scenarios.
  • Potential for Larger Outbreaks: In about two-thirds of simulations with only 20% isolation, total cases exceed 20,000 within three months, indicating possible outbreaks larger than 2014–2016 West Africa.
  • Case Count Updates: Confirmed and suspected case numbers change as diagnostic reviews continue. Updated data are available on the DRC Ministry of Health and CDC websites.
  • Community Transmission in Kampala: No evidence of community transmission; all cases trace back to travel from DRC.
  • Coordination with WHO Response Plan: CDC collaborates with U.S. government agencies, international partners, and country Ministries of Health to direct resources for outbreak control.
  • Accounting for Uncertainty: Modeling incorporated multiple death-count scenarios to address uncertainty after WHO adjusted suspected case numbers.

Conclusion

All MMWRs are available at www.cdc.gov/mmwr. The transcript and recording will be posted on the CDC media site. CDC remains committed to controlling and ending the Ebola outbreaks in DRC and Uganda while protecting U.S. public health.