News / Science & Technology

Gene Studies of Ebola in Sierra Leone Show Virus Mutating Fast

Reuters

Genetic studies of some of the earliest Ebola cases in Sierra Leone reveal more than 300 genetic changes in the virus as it leapt from person to person, changes that could blunt the effectiveness of diagnostic tests and experimental treatments now in development, researchers said on Thursday.

“We found the virus is doing what viruses do. It's mutating,” said Pardis Sabeti of Harvard University and the Broad Institute, who led the massive study of samples from 78 people in Sierra Leone, all of whose infections could be traced to a faith healer whose claims of a cure attracted Ebola patients from Guinea, where the virus first took hold.

The findings, published in Science, suggest the virus is mutating quickly and in ways that could affect current diagnostics and future vaccines and treatments, such as GlaxoSmithKline's Ebola vaccine, which was just fast-tracked to begin clinical trials, or the antibody drug ZMapp, being developed by California biotech Mapp Biopharmaceutical.

The findings come as the World Health Organization said that the epidemic could infect more than 20,000 people and spread to more countries. A WHO representative could not immediately be reached for comment on the latest genetic study.

Study coauthor Robert Garry of Tulane University said the virus is mutating at twice the rate in people as it was in animal hosts, such as fruit bats.

Garry said the study has shown changes in the glycoprotein, the surface protein that binds the virus to human cells, allowing it to start replicating in its human host. “It's also what your immune system will recognize,” he said.

In an unusual step, the researchers posted the sequences online as soon as they became available, giving other researchers early access to the data.

Erica Ollmann Saphire of the Scripps Research Institute in La Jolla, California, has already checked the data to see if it impacts the three antibodies in ZMapp, a drug in short supply that has been tried on several individuals, including the two U.S. missionaries who contracted Ebola in Sierra Leone and who have since recovered.

“It appears that they do not [affect ZMapp],” said Saphire, who directs a consortium to develop antibody treatments for Ebola and related viruses. But she said the data “will be critical to seeing if any of the other antibodies in our pool could be affected.”

Saphire said the speed with which Sabeti and colleagues mapped genetic changes in the virus gives researchers information that “will also be critical” to companies developing RNA-based therapeutics.

That could impact treatments under way from Vancouver-based Tekmira Pharmaceuticals and privately-held Profectus BioSciences of Tarrytown, New York.

Part of what makes the data useful is the precise picture it paints as the epidemic unfolded. Sabeti credits years of work by her lab, colleagues at Tulane and the Sierra Leone Ministry of Health and Sanitation in developing a response network for Lassa fever, a virus similar to Ebola that is endemic in West Africa.

Several of the study authors gave their lives to the work, including Dr. Sheik Humarr Khan, the beloved “hero” doctor from the Kenema Government Hospital, who died from Ebola.

The team had been doing surveillance for two months when the first case of Ebola arrived from Guinea on May 25. That case involved a “sowei” or tribal healer, whose claim of a cure lured sick Ebola victims from nearby Guinea.

“When she contracted Ebola and died, there were a lot of people who came to her funeral,” Garry said. One of these was a young pregnant woman who became infected and traveled to Kenema Government Hospital, where she was diagnosed with Ebola.

With the Lassa surveillance team in place, they quickly began testing samples.

“We've been able to capture the initial spread from that one person and to follow all of these contacts and everything with sequencing,” Garry said.

The team used a technique called deep sequencing in which sequences are done repeatedly to generate highly specific results, allowing them to see not only how the virus is mutating from person to person, but how it is mutating in cells within the same person.

What is not clear from the study is whether the mutations are fueling the epidemic by allowing the virus to grow better in people and become easier to spread. That will require further tests in the lab, Garry said.

You May Like

Video In Ukraine's Nikishino, No House Untouched by Fighting

Ninety percent of homes in one small village were damaged or destroyed as government forces failed to stop a rebel advance More

Pakistan’s 'Last Self-Declared Jew' Attacked, Detained

Argument about the rights of non-Muslims in Pakistan allegedly results in mob beating well-known Jewish Pakistani More

Turkey Cracks Down on Political Dissent — Again

People daring to engage in political dissent ahead of upcoming general elections could find themselves in jail More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
In Their Own Words: Citizens of Kobanii
X
Mahmoud Bali
March 06, 2015 8:43 PM
Civilians are slowly returning to Kobani, after Kurdish fighters backed by coalition airstrikes fought off a four-month siege of the northern Syrian town by Islamic State militants. VOA Kurdish Service reporter Mahmoud Bali talked to some of those who have returned. We hear about the devastation of Kobani through their own words.
Video

Video In Their Own Words: Citizens of Kobani

Civilians are slowly returning to Kobani, after Kurdish fighters backed by coalition airstrikes fought off a four-month siege of the northern Syrian town by Islamic State militants. VOA Kurdish Service reporter Mahmoud Bali talked to some of those who have returned. We hear about the devastation of Kobani through their own words.
Video

Video In Ukraine's Nikishino, No House Untouched by Fighting

In the village of Nikishino, in eastern Ukraine, recent fighting has brought utter devastation. Ninety percent of the houses are damaged or destroyed after government forces tried and failed to stop rebels advancing on the strategically important town of Debaltseve nearby. Patrick Wells reports for VOA from Nikishino.
Video

Video Crime Scenes Re-Created in 3-D Visualization

Police and prosecutors sometimes resort to re-creations of crime scenes in order to better understand the interaction of all participants in complicated cases. A Swiss institute says advanced virtual reality technology can be used for quality re-creations of events at the moment of the crime. VOA’s George Putic reports.
Video

Video Sierra Leone Ebola Orphans Face Another Crisis

There's growing concern about the future of an orphanage run by a British charity in Sierra Leone, after a staff member and his wife died this week from Ebola. The Saint George Foundation Orphanage in Freetown is now in quarantine, with more than 20 children and seven staff in lock-down. The BBC has agreed to share Ebola-related material with Voice of America because of the difficulties faced by media organizations reporting the crisis. Clive Myrie reports from Sierra Leone.
Video

Video Growing Concerns Over Whether Myanmar’s Next Elections Will Be Fair

Myanmar has scheduled national elections for November that are also expected to include a landmark referendum on the country's constitution. But there are growing concerns over whether the government is taking the necessary steps to prepare for a free and fair vote. VOA Correspondent Steve Herman was recently in Myanmar and files this report from our Southeast Asia bureau in Bangkok.
Video

Video Nigeria’s Ogonis Divided Over Resuming Oil Production

More than two decades ago, Nigeria’s Ogoni people forced Shell oil company to cease drilling on their land, saying it was polluting the environment. Now, some Ogonis say it’s time for the oil to flow once again. Chris Stein reports from Kegbara Dere, Nigeria.
Video

Video Fuel Shortages in Nigeria Threaten Election Campaigns

Nigeria is suffering a gas shortage as the falling oil price has affected the country’s ability to import and distribute refined fuels. Coming just weeks before scheduled March 28 elections, the shortage could have a big impact on the campaign, as Henry Ridgwell reports for VOA.
Video

Video Report: Human Rights in Annexed Crimea Deteriorating

A new report by Freedom House and the Atlantic Council of the United States says the human rights situation in Crimea has deteriorated since the peninsula was annexed by Russia in March of last year. The report says the new authorities in Crimea are discriminating against minorities, suppressing freedom of expression, and forcing residents to assume Russian citizenship or leave. Zlatica Hoke has more.
Video

Video 50 Years Later African-Americans See New Voting Rights Battles Ahead

Thousands of people will gather to mark the 50th anniversary of a historic civil rights march on March 7th in Selma, Alabama. In 1965, dozens of people were seriously injured during the event known as “Bloody Sunday,” after police attacked African-American demonstrators demanding voting rights. VOA’s Chris Simkins introduces us to some civil rights pioneers who are still fighting for voting rights in Alabama more than 50 years later.
Video

Video Craft Brewers Taking Hold in US Beer Market

Since the 1950’s, the U.S. beer industry has been dominated by a handful of huge breweries. But in recent years, the rapid rise of small craft breweries has changed the American market and, arguably, the way people drink beer. VOA’s Jeff Custer reports.
Video

Video Video Claims to Show Shia Forces in Iraq Executing Sunni Boy

A graphic mobile phone video is spreading on the Internet, claiming to show Iraqi forces or Shia militia executing a handcuffed Sunni boy. Experts have yet to verify the video, but already Islamic State followers are publicizing it across social media, playing on deep-rooted sectarian fears. VOA’s Jeff Seldin reports.
Video

Video Ukrainian Authorities Struggle to Secure a Divided Mariupol

Since last month's cease-fire went into effect, shelling around the port city of Mariupol has decreased, but it is thought pro-Russian separatists remain poised to attack. For the city’s authorities, a major challenge is gaining the trust of residents, while at the same time rooting out informants who are passing sensitive information to the rebels. Patrick Wells reports for VOA.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More