Scientists have discovered fresh insights into the lingering presence of the Ebola virus within the body even after apparent recovery. In a recent study, researchers observed the virus remaining active and transmissible in laboratory-created brain-like structures for extended periods, shedding light on potential reasons for the long-term health issues experienced by some Ebola survivors.
Ebola virus disease, known for its severe and often fatal impact causing symptoms such as fever, vomiting, bleeding, and organ failure, has been a subject of interest due to its ability to persist within the body post-recovery. Past Ebola outbreaks have been suspected to originate from individuals carrying the virus long after apparent recuperation. Notably, a 2021 outbreak in Guinea was linked to a survivor infected during the 2014-16 epidemic, indicating the virus’s ability to remain dormant for years before resurfacing.
The study, published in Nature Microbiology, suggests that the brain could serve as a sanctuary for the virus to evade the body’s immune defenses. Using miniature lab-grown brain organoids, a team of researchers from the Icahn School of Medicine at Mount Sinai and the Bernhard Nocht Institute for Tropical Medicine, among other global collaborators, investigated the virus’s behavior post-infection. These brain organoids, derived from human stem cells and mimicking various cell types found in the central nervous system, allowed for a detailed examination of how the virus interacts within human brain tissue.
The findings revealed that Ebola and its related viruses could infect the brain-like tissue and sustain replication for up to 120 days, actively spreading between cells and generating infectious viral particles. Despite the immune response mounted by the infected tissue, it was insufficient to completely eradicate the virus, leading to persistent infection that could contribute to subsequent health complications in survivors, such as inflammation affecting the eyes, meninges, or brain.
Furthermore, the researchers identified genetic alterations in the virus as it persisted within the body, potentially aiding its prolonged survival. Lead author Dr. Lina Widerspick emphasized the importance of studying these mechanisms using organoids to enhance the understanding of how filoviruses endure in the human central nervous system and lead to severe outcomes like meningoencephalitis in Ebola survivors.
The ongoing threat of Ebola in certain regions of Africa underscores the significance of these findings in potentially improving survivor treatments and anticipating future outbreaks stemming from persistent infections. The researchers aim to expand their investigations to encompass other viruses, aiming to broaden the scope of knowledge in combating such infectious diseases.