HEALTHY LIVING

No, Ebola Is Not Mutating Into A 'Supervirus'

03/27/2015 11:52 am ET
Maciej Frolow via Getty Images

The Ebola virus that is causing the current outbreak in West Africa is not mutating as quickly as earlier reports had suggested, a new study finds. This finding helps allay fears that the virus could change into a more infectious or deadly form, the researchers said.

In the study, published online today (March 26) in the journal Science, researchers compared virus samples from people in Africa who became infected with Ebola up to nine months apart. They found that the viruses' genetic sequences were almost identical, meaning that the virus had undergone relatively few mutations — or changes in the genetic sequence — over that time period, the researchers said

"We do not see any evidence that the virus is mutating any more rapidly than has been reported in previous outbreaks," said Thomas Hoenen, a postdoctoral fellow in virology at the National Institutes of Health and one of the researchers on the study. [5 Things You Should Know About Ebola]

The new results are welcome news, experts said. In a 2014 study published in the journal Science, researchers had suggested that the Ebola virus in the West African epidemic was mutating twice as fast as other Ebola virus strains. In that study, researchers compared viral samples that were taken from people who became infected only three months apart, a relatively short time period, Hoenen said.

That finding "was surprising to us, so we wanted to look at a data set that goes over a much longer period of time," Hoenen told Live Science.

In the new study, the researchers compared viral samples collected from patients who were infected in Guinea in March 2014, Sierra Leone in June 2014 and Mali in November 2014.

The researchers found that the samples from March and November differed by only 20 nucleotides out of 19,000. (Nucleotides hold the "letters" of the genetic code — for example, guanine (G) or adenine (A)).

None of the mutations that the researchers observed in the study will increase the severity or change the transmissibility of Ebola, the researchers said.

Researchers have been studying Ebola's mutation rate in part because the virus is an RNA virus, meaning it uses RNA, rather than its cousin DNA, for its genetic material. RNA viruses generally have higher mutation rates than DNA viruses, said Angela Rasmussen, a research assistant professor of microbiology at the University of Washington, who was not involved in the new study.

"[RNA viruses] don't have proofreading capabilities," like DNA viruses do, Rasmussen said. "If they make a mistake, they can't identify that and go back and fix it."

The new study suggests that the Ebola virus's mutation rate in West Africa is fairly similar to that of other RNA viruses, such as rhinovirus, the virus that causes the common cold, Rasmussen said.

The new study brought Rasmussen "a sense of relief," she told Live Science.

"It doesn't appear to be a supervirus," she said. "It basically indicates that our drugs and vaccines that were developed for Central African strains will probably still be effective against West African strains."

The Ebola outbreak in West Africa has now sickened more than 25,000 people and killed more than 10,300 people since it began, according to the Centers for Disease Control and Prevention. Several drug and vaccination trials are underway to help treat and prevent the disease.

Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

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  • 1 Ebola is highly infectious and even being in the same room as someone with the disease can put you at risk
    ASSOCIATED PRESS
    Not as far as we know. Ebola isn't contagious until symptoms begin, and it spreads through direct contact with the bodily fluids of patients. It is not, from what we know of the science so far, an airborne virus. So contact with the patient's sweat, blood, vomit, feces or semen could cause infection, and the body remains infectious after death. Much of the spread in west Africa has been attributed to the initial distrust of medical staff, leaving many to be treated at home by loved ones, poorly equipped medics catching the disease from patients, and the traditional burial rites involving manually washing of the dead body. From what we know already, you can't catch it from the air, you can't catch it from food, you can't catch it from water.
  • 2 You need to be worried if someone is sneezing or coughing hard
    ASSOCIATED PRESS
    Apart from the fact that sneezing and coughing aren't generally thought to be symptoms of Ebola, the disease is not airborne, so unless someone coughed their phlegm directly into your mouth, you wouldn't catch the disease. Though medical staff will take every precaution to avoid coming into contact with the body of an infected person at all costs, with stringent hygiene there should be a way to contain the virus if it reaches the UK.
  • 3 Cancelling all flights from west Africa would stop the spread of Ebola
    ASSOCIATED PRESS
    This actually has pretty serious implications. British Airways suspended its four-times-weekly flights to Liberia and Sierra Leone until the end of March, the only direct flight to the region from the UK. In practice, anyone can just change planes somewhere else and get to Britain from Europe, north Africa, or the Middle East. And aid agencies say that flight cancellations are hampering efforts to get the disease under control, they rely on commercial flights to get to the infected regions. Liberia's information minister, Lewis Brown, told the Telegraph this week that BA was putting more people in danger. "We need as many airlines coming in to this region as possible, because the cost of bringing in supplies and aid workers is becoming prohibitive," he told the Telegraph. "There just aren't enough seats on the planes. I can understand BA's initial reaction back in August, but they must remember this is a global fight now, not just a west African one, and we can't just be shut out." Christopher Stokes, director of MSF in Brussels, agreed: “Airlines have shut down many flights and the unintended consequence has been to slow and hamper the relief effort, paradoxically increasing the risk of this epidemic spreading across countries in west Africa first, then potentially elsewhere. We have to stop Ebola at source and this means we have to be able to go there.”
  • 4 Temperature screening at airports is an effective way to stop those who have the disease from travelling
    ASSOCIATED PRESS
    The screening process is pretty porous, especially when individuals want to subvert it. Wake up on the morning of your flight, feel a bit hot, and you definitely don't want to be sent to an isolation booth for days and have to miss your flight. Take an ibuprofen and you can lower your temperature enough to get past the scanners. And if you suspect you have Ebola, you might be desperate to leave, seeing how much better the treatment success has been in western nations. And experts have warned that you cannot expect people to be honest about who they have had contact with. Thomas Eric Duncan, the Ebola victim who died in Texas, told officials he had not been in contact with anyone with the disease, but had in fact visited someone in the late stages of the virus, though he said he believed it was malaria. The extra screening that the US implemented since his death probably wouldn't have singled out Duncan when he arrived from hard-hit Liberia last month, because he had no symptoms while travelling.
  • 5 Border staff should stop people coming in to the country who are at risk
    LEON NEAL via Getty Images
    They're not doctors, and it's a monumental task to train 23,500 people who work for the UK Border Agency how to correctly diagnose a complex disease, and spot it in the millions of people who come through British transport hubs. Public Health England has provided UK Border Force with advice on the assessment of an unwell patient on entry to UK, but they can't be expected to check everyone.
  • 6 Screening at British airports should be implemented to stop unwell people coming in from affected areas
    ASSOCIATED PRESS
    As mentioned before, the UK, especially London, is a major transport hub. Unlike the US, most of those coming from west Africa will have crossed through Europe, so infected people could be coming from practically anywhere, not just flights directly from those countries. This would require the UK to screen every returning traveller, as people could return to the UK from an affected country through any port of entry. This would be huge numbers of low risk people, at vast, vast expense.
  • 7 Ebola doesn't have a cure
    John Moore via Getty Images
    There are several cures currently being tested for Ebola. They include the ZMapp vaccine which was administered to British sufferer William Pooley and two other Americans who caught the disease in west Africa and they all recovered. Supplies of the drug have now run dry, and it has not been through clinical trials to prove its effectiveness. Mapp Biopharmaceutical, the company that makes ZMapp, says the drug's supplies are exhausted and that it takes months to make even a small batch. But an Ebola cure is very much on the horizon, and would have come sooner had it been seen as any kind of priority for drug companies before it started reaching the western world.
  • 8 Ebola is a death sentence
    ASSOCIATED PRESS
    It is true that certain strains of Ebola have had a death rate of 90%. However, with this particular epidemic the stats are more positive, a death rate of around 60%. Those who have decent, strong immune systems, are able to access intravenous fluids and scrupulous health care are far more likely to survive, which is why the survival rate of westerners who contract the disease is far better. Experts have suggested that, rather than waste money on pointless airport screenings, funds could be used to improve infrastructure in the affected nations to help halt the spread of the disease at source.
  • 9 Ebola turns you into a zombie
    Renee Keith via Getty Images
    Just, no.
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