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Scientists Find Ebola Virus Is Mutating

Significance of genetic changes remains unclear

Researchers at the Pasteur Institute in France have found that the Ebola virus is mutating “quite a lot,” causing concern in the African countries where the virus has killed an estimated 8,795 people, with a survival rate of around 40%.

The institute said that multiple mutations of the virus have been observed, although it is not clear what advantage this has given the virus, if any. The investigators also reported that they have seen many cases of people infected with the virus who did not exhibit any symptoms, which suggests that at least one of the viral mutations has led to infections that are less traumatic to their victim, but which are also probably more easily spread.

“We know the virus is changing quite a lot,” said human geneticist Dr. Anavaj Sakuntabhai. “That’s important for diagnosing [new cases] and for treatment. We need to know how the virus [is changing] to keep up with our enemy.”

It is not unusual for a virus to mutate, the institute said. Also, the Ebola virus is in a class –– an RNA virus-like human immunodeficiency virus (HIV) and influenza –– that is able to evolve via mutations very quickly. The team in France pointed out that the virus has not shown any signs of a change in its mode of transmission (physical contact), which is good news. If the virus becomes transmissible through the air, for example, it could spread much more quickly.

However, Professor David Heyman, an infectious disease expert at the University of Nottingham, commented: “No blood-borne virus –– for example, HIV or hepatitis B –– has ever shown any indication of becoming airborne. The mutation would need to be major.”

As the Ebola virus became evident, first in Guinea and then in other West African countries, researchers began studying it using techniques such as genetic sequencing, which allowed them to track changes in the virus’ genetic make-up. To date, the team at the Pasteur Institute has studied approximately 20 samples from people in Guinea and is awaiting the arrival of approximately 600 more samples in the next few months.

The World Health Organization (WHO) has reported that a similar study conducted in Sierra Leone indicated that the virus had mutated in just the first month of the outbreak.

Meanwhile, officials monitoring the outbreak reported that there were fewer than 100 new cases during a 1-week period recently, the fewest since shortly after the outbreak began. The WHO also announced that it considers the outbreak to be entering a new phase — the agency’s main focus now is on ending the epidemic.

Researchers at the Pasteur Institute are currently developing two Ebola vaccines that they hope will be in human trials by the end of the year.

Sources: Medical Xpress; January 30, 2015; and BBC News; January 29, 2015.


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