An international group of experts found that the levels of virus in the blood of an Ebola patient can help predict the risk of fatality from infection.
The team led by Amadou Alpha Sall and Simon Cauchemez, and conducted by scientists from Guinea and Canada, examined clinical, demographic and laboratory data that involved 699 Ebola patients in Guinea. These patients were hospitalized between March 2014 and February 2015.
In the study, which was featured in the journal PLOS ONE, the team of scientists discovered that in the week that followed the onset of symptoms, the levels of virus in the blood or viremia remained stable. They also found that the proportion of Ebola death cases to total cases or the case fatality ratio (CFR) increased with level of viremia.
The CFR for Ebola patients with low viremia was 21 percent; for Ebola patients with intermediate viremia was 53 percent; and for Ebola patients with high viremia was 81 percent.
Patients who were under 5 years old and patients who were 45 years old and over had higher CFR, while patients who were 5 to 14 years old had lower CFR, scientists said.
Researchers also noted that when the average viremia elevated 10-fold in July last year, the death rate also increased by 14 percent.
However, they said the results of the study may not apply outside a hospital setting.
Meanwhile, the 2014 Ebola epidemic led to 28,000 confirmed cases of the disease and caused 11,000 deaths in West Africa, making it the largest epidemic in history, researchers said.
"The scale of this outbreak was really something beyond our capacity and is still challenging our capacity," said Dr. Daniel Bausch, consultant for the World Health Organization. "Now we have thousands of survivors who need care. We need to develop a system for that."
The CFR of Ebola has changed significantly. Previous studies thought that factors such as the ability to detect patients with degrees of severity, time to hospitalization, patient care, the strain of the virus could affect the CFR.
Currently, there is no proven vaccine or treatment for Ebola, although some treatments are being evaluated.
This new study was funded by the U.S. National Institute of General Medical Sciences, the European Union, and the French government. Robert Fowler of the University of Toronto, the co-author of the study, was backed by the Heart and Stroke Foundation's Ontario Provincial Office.
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