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

Polls Open in Scotland Independence Vote

As race to persuade undecided voters continues, 'No' voters say they believe life in Scotland will slowly improve, 'Yes' vote not worth the risk More

South Africa’s 'Open Mosque' Admits Everyone, Including Critics

Open Mosque founder plans to welcome gay worshipers and allow women to lead prayers More

Ukrainian Activist in Despair About Future of Her Country

IrIna Dovgan, accused of being a spy and tortured by pro-Russian separatists, is appealing to UN Human Rights Council to support her country More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
A Dinosaur Fit for Land and Wateri
X
September 17, 2014 8:44 PM
Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.
Video

Video NASA Picks Boeing, SpaceX to Carry Astronauts Into Space

The U.S. space agency, NASA, has chosen Boeing and SpaceX companies to build the next generation of spacecraft that will carry U.S. astronauts to the International Space Station by the year 2017. The deal with private industry enables NASA to end its dependence on Russia to send space crews into low Earth orbit and back. Zlatica Hoke has more.
Video

Video Future of Ukrainian Former President's Estate Uncertain

More than six months after Ukraine's former President Viktor Yanukovych fled revolution to Russia, authorities have yet to gain control of his palatial estate. Protesters occupy the grounds and opened it to tourists but they are also refusing to turn it over to the state. VOA's Daniel Schearf reports from Mezhigirya, just north of Kyiv.
Video

Video China Muslims Work to Change Perceptions After Knife Attacks

China says its has sentenced three men to death and one woman to life in prison for a deadly knife attack in March that left more than 30 dead and 140 injured. Beijing says Muslim militants from China's restive western region of Xinjiang carried out the attacks. Now, more than six months after the incident, residents in the city are still coping with the aftermath. VOA's Bill Ide has more from Kunming.
Video

Video Enviropreneur Seeks to Save the Environment, Empower the Community

Lorna Rutto, a former banker, is now an ‘enviropreneur’ - turning plastic waste into furniture and fences discusses the challenges she faces in Africa with raw materials and the environment.
Video

Video West Trades Accusations Over Ransoms

As world leaders try to forge a common response to the threat posed by Islamic State militants in Iraq and Syria, there is simmering tension over differing policies on paying ransoms. In the past month, the jihadist group has beheaded two Americans and one Briton. Both countries refuse to pay ransom money. As Henry Ridgwell reports for VOA from London, there is uncertainty in the approach of some other European nations.
Video

Video Scotland Independence Bid Stokes Global Interest

The people of Scotland are preparing to vote on whether to become independent and break away from the rest of Britain, in a referendum being watched carefully in many other countries. Some see it as a risky experiment; while others hope a successful vote for independence might energize their own separatist demands. Foreign immigrants to Scotland have a front row seat for the vote. VOA’s Henry Ridgwell spoke to some of them in Edinburgh.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid