A new study published in the Clinical Infectious Disease Journal
may uncover the mystery behind why the Ebola virus disease is fatal to only some, and lead to pathways to new treatments.
Since the discovery of the Ebola virus in 1976, more than 30,000 individuals have been diagnosed with the virus. Despite this, the mechanism through which the virus causes severe illness is yet to be known.
Using samples extracted from patients in both stages of illness and recovery, researchers from the Centers for Disease Control and Prevention (CDC), Emory University School of Medicine, and University of Nebraska Medical Center “tracked 54 different markers of immune-system activity from hospital admission until the day of discharge,” in seven patients in the United States, according to a press release
. Five of these patients had moderate Ebola virus disease (EVD), while two developed severe EVD and required mechanical ventilation and dialysis.
Lead author, Anita McElroy, MD, PhD, guest researcher at the CDC Viral Special Pathogens Branch, assistant professor, Emory University School of Medicine, and pediatrician, Grady Memorial Hospital, Emory University, stated that having identified the particular immune system components that combated the virus in the surviving patients, the researchers now know which parts of the immune system should be targeted in the development of new therapies to combat the virus.
Study results revealed that those patients who suffered from severe EVD had higher viremia and “out-of-control” responses, which lead to multisystem organ failure, shock, and the destruction of healthy tissues. In some cases, this even lead to death. On the other hand, those with moderate EVD showed healthier immune responses to the virus. Among the study participants, all of those with moderate EVD survived, while only one with the severe form of the disease survived.
CDC Director, Tom Frieden, MD, MPH, commented on the study’s findings, stating, “These findings are encouraging and underscore how crucial it is to continue the fight against Ebola… We must come up with new ways to keep people safe and combat diseases that threaten our health.”
Although researchers are still unsure exactly why some people are better able to fight off Ebola than others, they believe that genetics, along with underlying comorbidities, often play a role in the immune system’s response to the virus.
According to the press release, “Identifying which parts of the immune system malfunction in severe EVD cases as well as the parts that function well in the moderate cases could lead to the design of therapies that might theoretically inhibit the disease’s progression.”
To stay informed on the latest in infectious disease news and developments, please sign up for our weekly newsletter.