Researchers conduct molecular analysis of the 2021 Bundibugyo virus outbreak

New research offers insight into the origins of the 2012 Bundibugyo viral disease outbreak in the Democratic Republic of the Congo. The research illustrates the significance of employing high-throughput sequencing to comprehend virus “spillover” events to efficiently manage disease outbursts.

A researcher prepares a sample for genomic analysis at the U.S. Army Medical Research Institute of Infectious Diseases, where scientists are using next-generation sequencing to improve disease surveillance. Image Credit: Photo by John W. Braun, Jr, USAMRIID Visual Information Office.

The research findings were published on July 27^th, 2021, in the Cell Reports Medicine journal.

The recent research by a team of international researchers headed by the US Army Medical Research Institute of Infectious Diseases depicts the use of high-throughput sequencing—one of USAMRIID’s core competencies—to retrospectively identify the origins of a disease outburst and offer vital information on the emerging pathogens of public health and military importance.

Bundibugyo virus is one of four ebolaviruses that cause disease to humans, and many outbreaks have been reported on the African continent. It is marked by flu-like symptoms that are at times accompanied by vomiting, diarrhea, hemorrhage, and chest pain. Survivors experience blurred vision, joint pain, and hearing loss.

Similar to other ebolaviruses, the “reservoir” of Bundibugyo—that is, the primary host that harbors the virus—is yet unknown, assert the researchers. Hence, the ecology of the virus and its mode of transmission into the human population are scarcely understood.

The outburst of 2012 led to 38 laboratory-confirmed cases of human infection, 13 of whom died. But only 4 patient specimens of that outbreak have been sequenced to date, reports MAJ Jeffrey R. Kugelman, Ph.D., one of the lead authors of the study.

USAMRIID’s analysis of sequences from seven more patients reveals that multiple virus “spillover” events resulted in the outbreak—not a single event, as described earlier—and that one of the spillover events likely emerged weeks prior than previously thought.

Analysis of the molecular epidemiology and evolutionary dynamics of the 2012 outbreak with these additional isolates challenges the current hypothesis that the outbreak was the result of a single spillover event. In addition, phylogenetic analysis suggests that the initial emergence of the virus occurred 50 days earlier than previously accepted.”

MAJ Christine Hulseberg, PhD, Study First Author, United States Army Medical Research Institute of Infectious Diseases

Along with performing a vital role in pinpointing chains of transmission as an outbreak unfolds, viral genome sequencing provides researchers with a greater picture of the general patterns of spread and enlightens public health efforts to control future outbreaks. It also enables the investigation of genetic mutations that could affect the capability of the virus to survive and cause the disease.

The research was performed at USAMRIID as part of an ongoing Ebola virus response and surveillance effort under the project, “Assessment of Human Clinical Samples from Viral Hemorrhagic Fevers of Known and Unknown Etiology.”

It is the first of the many planned associations with the Icahn School of Medicine at Mount Sinai, New York, laying the groundwork for future joint research initiatives to protect national and global public health.

USAMRIID’s collaboration with ISMMS is planned to enhance the impact of DoD’s research, development, and testing, as well as evaluation investment by assuring integration and cooperation with biomedical infectious disease research centers catering to similar goals.