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

Photogallery Snowstorm Sweeps Northeastern US

'This is nothing like we feared it would be,' New York City Mayor Bill de Blasio says; he had earlier warned storm could be one of worst the city has ever faced More

Millions of Displaced Nigerians Struggle With Daily Existence

Government acknowledges over a million people displaced in 2014 due to fight against Boko Haram insurgency More

Facebook: Internal Error to Blame for Outages

Temporary outage appeared to spill over and temporarily slow or block traffic to other major Internet sites More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Obama Urges Closer Economic Ties During Historic India Visiti
X
Aru Pande
January 26, 2015 9:33 PM
U.S. President Barack Obama says the United States and India must do better to capitalize on untapped potential in their economic relationship - by removing some of the roadblocks to greater trade and investment. As VOA correspondent Aru Pande reports from New Delhi, Obama spoke after participating in India’s Republic Day celebration.
Video

Video Obama Urges Closer Economic Ties During Historic India Visit

U.S. President Barack Obama says the United States and India must do better to capitalize on untapped potential in their economic relationship - by removing some of the roadblocks to greater trade and investment. As VOA correspondent Aru Pande reports from New Delhi, Obama spoke after participating in India’s Republic Day celebration.
Video

Video US, EU Threaten New Russia Sanctions Over Ukraine

U.S. President Barack Obama has blamed Russia for an attack by Ukrainian separatists that left dozens dead in the port of Mariupol and cast further doubt on the viability of last year’s cease-fire with the Kyiv government. VOA’s Michael Bowman reports from Washington.
Video

Video White House Grapples With Yemen Counterterrorism Strategy

Reports say the U.S. has carried out a drone strike on suspected militants in Yemen, the first after President Barack Obama offered reassurances the U.S. is continuing its counterterrorism operations in the country. The future of those operations has been in question following the collapse last week of Yemen’s government. VOA White House correspondent Luis Ramirez reports.
Video

Video Kerry Warns Against Violence in Nigeria Election

US Secretary of State John Kerry visited Nigeria Sunday in a show of the level of concern within the U.S. and the international community over next month’s presidential election. Chris Stein reports.
Video

Video Zoo Animals Show Their Artistic Sides

The pursuit of happiness is so important, America's founding fathers put it in the Declaration of Independence. Any zookeeper will tell you animals need enrichment, just like humans do. So painting, and even music, are part of the Smithsonian National Zoo's program to keep the animals happy. VOA’s June Soh met some animal artists at the zoo in Washington. Faith Lapidus narrates.
Video

Video Worldwide Photo Workshops Empower Youth

Last September, 20 young adults from South Sudan took part in a National Geographic Photo Camp. They are among hundreds of students from around the world who have learned how to use a camera to tell the stories of the people in their communities through the powerful medium of photography. Three camp participants talked about their experiences recently on a visit to Washington. VOA’s Julie Taboh reports.
Video

Video Saudi, Yemen Developments Are Sudden Complications for Obama

The death of Saudi Arabia's King Abdullah and the collapse of Yemen’s government have cast further uncertainty on U.S. efforts to fight militants in the Middle East and also contain Iran’s influence in the region. VOA White House correspondent Luis Ramirez reports on the new complications facing the Obama administration and its Middle East policy.
Video

Video Progress, Some Areas of Disagreement in Cuba Talks

U.S. and Cuban officials are reporting progress from initial talks in Havana on re-establishing diplomatic ties. U.S. Assistant Secretary of State (for Western Hemisphere Affairs) Roberta Jacobson said while there was agreement on a broad range of issues, there also are some “profound disagreements” between Washington and Havana. VOA State Department correspondent Pam Dockins has the story.
Video

Video US, Japan Offer Lessons as Eurozone Launches Huge Stimulus

The Euro currency has fallen sharply after the European Central Bank announced a bigger-than-expected $67 billion-a-month quantitative easing program Thursday - commonly seen as a form of printing new money. Henry Ridgwell reports for VOA from London on whether the move might rescue the eurozone economy -- and what lessons have been learned from similar programs around the world.
Video

Video Nigerian Elections Pose Concern of Potential Conflict in 'Middle Belt'

Nigeria’s north-central state of Kaduna has long been the site of fighting between Muslims and Christians as well as between people of different ethnic groups. As the February elections approach, community and religious leaders are making plans they hope will keep the streets calm after results are announced. Chris Stein reports from the state capital, Kaduna.
Video

Video As Viewership Drops, Obama Puts His Message on YouTube

Ratings reports show President Obama’s State of the Union address this week drew the lowest number of viewers for this annual speech in 15 years. White House officials anticipated this, and the president has decided to take a non-traditional approach to getting his message out. VOA White House correspondent Luis Ramirez reports.
Video

Video S. Korean Businesses Want to End Trade Restrictions With North

Business leaders in South Korea are calling for President Park Geun-hye to ease trade restrictions with North Korea that were put in place in 2010 after the sinking of a South Korean warship.Pro-business groups argue that expanding trade and investment is not only good for business, it is also good for long-term regional peace and security. VOA’s Brian Padden reports.

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

All About America

AppleAndroid