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

Changing Under Pressure, IS ‘Potent’ as Ever

US intel officials describe Ramadi's fall as concerning, but say it isn't emblematic of larger effort to degrade IS capabilities More

Nigeria Fuel Shortage Shows Fragility of Africa’s Oil Giant

Although it is the largest oil producer in Africa, country has nearly ran out of fuel it needs to power its generators, cars and airplanes over the past week More

Arrested Football Officials Come Mainly From the Americas

US Justice Department alleges defendants participated in 24-year scheme to enrich themselves through corruption of international soccer More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
3D Printer Makes Replica of Iconic Sports Cari
|| 0:00:00
...    
🔇
X
George Putic
May 27, 2015 9:31 PM
Cars with parts made by 3D printers are already on the road, but engineers are still learning about this new technology. While testing the possibility of printing an entire car, researchers at the U.S. Department of Energy recently created an electric-powered replica of an iconic sports roadster. VOA’s George Putic has more.
Video

Video 3D Printer Makes Replica of Iconic Sports Car

Cars with parts made by 3D printers are already on the road, but engineers are still learning about this new technology. While testing the possibility of printing an entire car, researchers at the U.S. Department of Energy recently created an electric-powered replica of an iconic sports roadster. VOA’s George Putic has more.
Video

Video US Voters Seek Answers From Presidential Candidates on IS Gains

The growth of the Islamic State militant group in Iraq and Syria comes as the 2016 U.S. presidential campaign kicks off in the Midwest state of Iowa.   As VOA’s Kane Farabaugh reports, voters want to know how the candidates would handle recent militant gains in the Middle East.
Video

Video A Small Oasis on Kabul's Outskirts Provides Relief From Security Tensions

When people in Kabul want to get away from the city and relax, many choose Qargha Lake, a small resort on the outskirts of Kabul. Ayesha Tanzeem visited and talked with people about the precious oasis.
Video

Video Film Festival Looks at Indigenous Peoples, Culture Conflict

A recent Los Angeles film festival highlighted the plight of people caught between two cultures. Mike O'Sullivan has more on the the Garifuna International Film Festival, a Los Angeles forum created by a woman from Central America who wants the world to know more about her culture.
Video

Video Kenyans Lament Losing Sons to al-Shabab

There is agony, fear and lost hope in the Kenyan town of Isiolo, a key target of a new al-Shabab recruitment drive. VOA's Mohammed Yusuf visits Isiolo to speak with families and at least one man who says he was a recruiter.
Video

Video Scientists Say Plankton More Important Than Previously Thought

Tiny ocean creatures called plankton are mostly thought of as food for whales and other large marine animals, but a four-year global study discovered, among other things, that plankton are a major source of oxygen on our planet. VOA’s George Putic reports.
Video

Video US-led Coalition Gives Some Weapons to Iraqi Troops

In a video released Tuesday from the Iraqi Ministry of Defense, Iraqi forces and U.S.-led coalition troops survey a cache of weapons supplied to help Iraq liberate Mosul from Islamic State group. According to a statement provided with the video, the ministry and the U.S.-led coaltion troops have started ''supplying the 16th army division with medium and light weapons in preparation to liberate Mosul and nearby areas from Da'esh (Arabic acronym for Islamic State group).''
Video

Video Amnesty International: 'Overwhelming Evidence' of War Crimes in Ukraine

Human rights group Amnesty International says there is overwhelming evidence of ongoing war crimes in Ukraine, despite a tentative cease-fire with pro-Russian rebels. Researchers interviewed more than 30 prisoners from both sides of the conflict and all but one said they were tortured. Henry Ridgwell reports for VOA from London.
Video

Video Washington Parade Honors Those Killed Serving in US Military

Every year, on the last Monday in the month of May, millions of Americans honor the memories of those killed while serving in the armed forces. Memorial Day is a tradition that dates back to the 19th Century. While many people celebrate the federal holiday with a barbecue and a day off from work, for those who’ve served in the military, it’s a special day to remember those who made the ultimate sacrifice. Arash Arabasadi reports for VOA from Washington.
Video

Video Kenya’s Capital Sees Rise in Shisha Parlors

In Kenya, the smoking of shisha, a type of flavored tobacco, is the latest craze. Patrons are flocking to shisha parlors to smoke and socialize. But the practice can be addictive and harmful, though many dabblers may not realize the dangers, according to a new review. Lenny Ruvaga has more on the story for VOA from Nairobi, Kenya.
Video

Video Rolling Thunder Run Reveals Changed Attitudes Towards Vietnam War

For many US war veterans, the Memorial Day holiday is an opportunity to look back at a divisive conflict in the nation’s history and to remember those who did not make it home.
Video

Video Female American Soldiers: Healing Through Filmmaking

According to the United States Defense Department, there are more than 200-thousand women serving in the U.S. Armed Forces.  Like their male counterparts, females have experiences that can be very traumatic.  VOA's Bernard Shusman tells us about a program that is helping some American women in the military heal through filmmaking.

VOA Blogs