In 2014 western Africa was in the grips of the worst outbreak of Ebola ever recorded. By 2016 it had killed more than 11,000 people.

One of the questions on researchers’ minds since the outbreak was declared over has been why those 11,000 died out of the 28,000 reported cases of infection.

There are some obvious factors; supportive hospital care improves prognosis, whilst a high amount of virus in the body increases likelihood of death. But these factors alone didn’t always predict who would live or die. So what else could be at play? And could research into the issue provide us with valuable information to stop a similar epidemic spreading again?

A team of researchers led by Boston University has discovered a biomarker that they say can help predict the progression of the disease. A handful of genes that are over-activated and therefore produce an overly aggressive immune response to the virus have been found in those that succumb to the disease. This response can damage organs—particularly the liver—and therefore hamper a more targeted immune response.

The research team discovered the biomarker whilst analyzing blood samples from the 2014 Ebola epidemic. A/Prof John Connor, an author on the study, said;

“The study suggests that something about the way people respond to infection affects their chance of survival. We can get a sense of who will survive and who won’t, and we can get it earlier.”

The blood test is in the preliminary development stages and the study is limited (samples were used from the 2014 outbreak which involved only one strain of the virus) but A/Prof Connor believes it is likely similar biomarkers will appear with other strains. And the team are optimistic that it might be useful in future outbreaks to steer patients to the best treatment. Connor added;

“The nature of the victim’s immune response has something to do with it, but the information we got from these samples is a one-time snapshot. This study gives us an important piece of information, but it doesn’t solve the whole puzzle.”

Read more on the Boston University website or see the full study published in the journal Genome Biology, suggests a new type of blood test that while still in the preliminary stages of development, might be useful in