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PostPosted: Wed Dec 31, 2014 12:20 am 

Joined: Wed Aug 19, 2009 10:42 am
Posts: 56044
Location: Pittsburgh, PA USA
Source of Ebola Outbreak in West Africa Might Be Bats, Study Says
DEC. 30, 2014

The toddler in Guinea who is thought to have been the first case in the current outbreak of Ebola in West Africa may have caught the virus from bats in a hollow tree near his village, scientists said Tuesday.

A study, led by scientists from the Robert Koch Institute in Berlin and published online by the journal EMBO Molecular Medicine, could not prove the link because the tree in Meliandou, a village of 31 houses in the Guéckédou district, burned in late March and the bats inside were immolated or flew off.

The fire took place shortly after Guineans were warned that the virus might come from bats. By then, at least 10 local people were dead.

However, the scientists found enough residual DNA in the charred trunk and fecal DNA in nearby soil to identify the animals as Mops condylurus, long-tailed insect-eating bats that were previously suspected in an outbreak of the Sudan strain of Ebola virus, which is related to the Zaire strain that has infected over 20,000 West Africans.

The study is important because scientists have wondered how a boy named Emile Ouamouno, who died in December 2013 and whom various reports describe as 1 or 2 years old, could have been the index patient.

Most human outbreaks have started in adults: hunters or charcoal-burners finding sick apes or forest antelopes and butchering them for food, for example, or miners working in bat-filled caves. In one case, an outbreak is thought to have come from bats roosting in a cotton mill.

But there was no large number of deaths among chimpanzees or other animals in the Meliandou area, the scientists said.

Large fruit bats have been suspected because they are hunted for meat in Guinea, where a peppery bat soup was popular before the outbreak.

Some scientists think that humans can contract Ebola by picking up fruit that fruit bats have contaminated with saliva or feces.

But there are no fruit bat colonies near Meliandou, the study said. Local men who hunted them during the migratory season had to walk long distances. Also, none of the initial cases in the village involved bat hunters.

The scientists captured several bat species near the village, but none had the virus or the antibodies to it.

Villagers said that children, including Emile, often caught and played with bats in the tree, which was about 50 yards from Emile’s house and near a path women used to fetch water.

The work was done by a team that included an anthropologist to investigate human interaction with animals, 10 ecologists to survey local wildlife and four veterinarians who netted bats, taking blood and tissue samples.

Normally, the bats are released unharmed, but Fabian Leendertz, the lead author, told the magazine Scientific American that his team had killed them. Otherwise, he said, local people would have said, “Look at those white people releasing bad bats.”

Rumors that whites and people from the capital cities had started the epidemic led to confrontations and the murders of several health care workers.

A version of this article appears in print on December 31, 2014, on page A4 of the New York edition with the headline: Source of Ebola Outbreak Might Be Bats, Study Says. Order Reprints| Today's Paper|Subscribe

http://www.nytimes.com/2014/12/31/healt ... .html?_r=0


PostPosted: Wed Dec 31, 2014 12:22 am 

Joined: Wed Aug 19, 2009 10:42 am
Posts: 56044
Location: Pittsburgh, PA USA
Investigations yield insights into Ebola outbreak's early months
Filed Under: Ebola
Lisa Schnirring | Staff Writer | CIDRAP News | Dec 30, 2014

With West Africa's Ebola epidemic passing the 1-year mark, two new reports yielded details about factors that fueled the event, including bats in a hollow tree that may have infected the index patient, a young Guinean child, and a silent chain of transmission that caused the disease to flare again in May after cases had sharply dropped off.

Also today, the World Health Organization (WHO) updated its Ebola numbers, saying there have been 20,129 cases, along with 7,879 deaths, in the three hardest-hit countries. The data include cases reported through Dec 28 in Guinea and Sierra Leone and through Dec 24 in Liberia. The totals reflect an increase of 48 cases and 37 deaths since the WHO's update yesterday.

In addition, the WHO today posted a new timeline of the event, starting with its African regional office's first report on the outbreak on Mar 23.

Bat colony suspected as virus source
The bat study, by a multidisciplinary group of German-led researchers, was conducted in April in the area around Meliandou, a village in a plantation region of Guinea where a 2-year-old boy thought to have been the index patient lived. The team published its findings today in an online edition of EMBO Molecular Medicine.

The 4-week investigation of the roots of zoonotic transmission where the outbreak began involved a field team that included anthropologists who looked at human exposure to bush meat and bats, ecologists who surveyed local wildlife, and veterinarians who analyzed samples from bats and other animals.

In other Ebola outbreaks, the virus was known to take a toll on larger animals, such as wild apes. However, the team found no evidence of population declines in the region's wildlife populations. Also, children and women were among the first victims in the outbreak, rather than hunters, also suggesting that the virus probably didn't jump from a larger animal.

Hunting and butchering fruit bats—a suspected Ebola reservoir—were common activities in southern Guinea, providing a link to humans. Also, the team found that children often hunt and grill insect-eating bats in and around villages, providing more exposure to the animals.

Though the group didn't find any large colonies of bats in or near Meliandou, villagers showed them a large tree stump from a hollow tree near which the village children, including the index case, frequently played, catching and playing with bats. They said the tree burned on Mar 24, triggering a "rain of bats" that were collected to eat. However, the local people disposed of them after authorities the next day imposed a ban on consuming bush meat.

Genetic sequencing of the environment near the tree confirmed that small free-tail bats had been in the area, the same type the villagers described.

The team said the circumstances may have led to a massive exposure to bats, similar to events in bat-inhabited caves that have been implicated in the zoonotic transmission of Marburg virus. They added that their findings confirm the index case but suggest a slightly different transmission timeline, with the virus spreading to other parts of Guinea, then to Sierra Leone and other countries. Local people told the researchers that the boy died on Dec 28, several weeks later than the Dec 6 date reported in the medical literature.

Times piece describes missed opportunities
An undetected transmission chain was one of several missteps that led to the Ebola outbreak's unprecedented size, according to an in-depth look at the events by a team of reporters from the New York Times. The report, based on a 2-month investigation, was first published yesterday.

The report describes how experts thought the outbreak was close to burning itself out, with sharply declining at the beginning of May, along with clues they may have missed that an unusual event was about to unfold, and missteps in the response.

Focusing on the time frame of the lull and the spike that followed, the team found that WHO and Guinean officials documented a handful of suspected cases across the border in Sierra Leone in March, but that information about two of the cases never got to senior health officials and investigators. This circumstance appears to have led to a chain of transmission that went unchecked for 2 months and didn't surface until late May, when Sierra Leone confirmed its first Ebola case.

The report also says the same two cases that fell through the cracks sparked a second wave of illnesses in Liberia that began in late May.

Experts involved in the early response told the reporters that they didn't deploy enough staff to the region and pulled them too soon. They also described management glitches by the WHO, which was stretched thin by budget cuts and other health and humanitarian crises.

Other factors that hobbled the response included some officials' downplaying of the Ebola threat and public education campaigns that did more harm than good, such as early efforts that highlighted the lethality of the disease.

In tracing the first illnesses, including the boy who had the index case, investigators made faulty assumptions, and it took 12 weeks to determine that the illnesses and deaths were caused by Ebola, according to the report.

The WHO's African regional office, initially appointed to lead the response, was suffering from sharp cuts in preparedness money and staff and was overmatched in its ability to handle the task, and it posed bureaucratic roadblocks in getting help from global experts, the article says.

In the first few months of the outbreak, lack of cross-border coordination hampered the response, and officials arriving from outside West Africa lacked a full understanding of the political and cultural challenges they would face, including deep distrust of government.

The Times team pointed out that Doctors without Borders declared the outbreak out of control on Jun 21, but the WHO didn't declare a public health emergency of international concern until Aug 8.

Health officials who spoke with the Times said they wish they had devoted more staff and resources to the outbreak early on and had recognized how weak contact tracing was and the distinct culture of West Africa.

Pierre Rollin, MD, a top Ebola expert at the US Centers for Disease Control and Prevention, who was quoted extensively in the Times report, said some of the events couldn't have been predicted, especially in the midst of an unfolding crisis. "There were a lot of things we didn't know at that time. No one could have imagined that it would be what we have now," he said.

See also:

Dec 30 EMBO Molecular Medicine study

Dec 29 New York Times story

Dec 30 WHO timeline

Dec 30 WHO situation summary

http://www.cidrap.umn.edu/news-perspect ... rly-months


PostPosted: Wed Dec 31, 2014 12:28 am 

Joined: Wed Aug 19, 2009 10:42 am
Posts: 56044
Location: Pittsburgh, PA USA
Insect-Eating Bat May Be Origin of Ebola Outbreak, New Study Suggests
The first Ebola victim may have contracted the disease from small bats dwelling in a hollow tree.
A dissected insect bat pinned to a pad at a makeshift laboratory. The samples will be frozen in liquid nitrogen and sent to a lab in Berlin, Germany.
An insect-eating bat, like this one dissected in a makeshift laboratory in western Africa, may have been the source of this year's Ebola outbreak.


David Quammen
for National Geographic

While people in West Africa continue to die from Ebola, scientists are pondering a mystery that has eluded them since the first known outbreak of the virus among humans, in 1976: Where does this fearful bug hide when it’s not killing people?

A new hypothesis described Tuesday in EMBO Molecular Medicine presents an unexpected scenario of how Ebola 2014 may have gotten started. The study suggests that the virus may have passed into its first human victim, a child, from a small insect-eating bat, an animal so diminutive that it is hunted by children but not by adults.

Ebola virus is a zoonosis, meaning an infectious agent that lives inconspicuously and innocuously within some nonhuman animal (its reservoir host) and spills over occasionally into humans, causing disease.

Fruit bats, which are relatively large and meaty, have often been touted as suspects, but the virus’s reservoir host has never been positively identified. The gold standard of proof—culturing live virus from the tissues or blood of a candidate animal—hasn’t ever been achieved from fruit bats, nor from any other creature. So the virus is still at large, its reservoir indeterminate, its whereabouts unknown, somewhere within the landscape of tropical Africa.

The first known victim of the 2014 Ebola epidemic was two-year-old Emile Ouamouno, shown in a family photo in Méliandou, Guinea.
Tracking a Killer

The Ebola epidemic of 2014, which has now totaled almost 20,000 cases and at least 7,708 deaths, began quietly in southeastern Guinea slightly more than a year ago. News of the outbreak reached the wider world last March, and within weeks Fabian Leendertz of the Robert Koch Institute in Berlin assembled a multidisciplinary team that included ecologists and veterinarians, plus an anthropologist to interview local people, and traveled to the affected area, near the borders of Liberia and Ivory Coast.

Surveying wildlife in forests there, the scientists found no evidence of a die-off among larger animals, such as duikers, monkeys, and chimpanzees, that are also susceptible to Ebola. This suggested that perhaps the virus had spilled over directly from its reservoir host into humans, without passing through other animals hunted or scavenged for food.
Map showing the location of Méliandou, Guinea
The team then focused on a village called Méliandou, in Guinea—the index village, where the human outbreak began. A young boy, Emile Ouamouno, was the earliest known victim. He died with Ebola-like symptoms in Méliandou back in December 2013, followed soon by his mother, sister, and grandmother. No adult males died in the first wave of the outbreak, another clue that seemed to point away from hunted wildlife as the origin of the virus.

During eight days in Méliandou, Leendertz’s team gathered testimony from survivors and collected samples, including blood and tissues from captured bats. From these data emerged the new hypothesis: Maybe the reservoir host was a bat, yes—but a very different sort of bat, in a different ecological relationship with humans.

While fruit bats are abundant in southeastern Guinea, they don’t roost in large aggregations near Méliandou. But the village did harbor a sizable number of small, insectivorous bats, which roosted under the roofs of houses and in natural recesses, such as hollow trees. The locals call them lolibelo.

“These bats are reportedly targeted by children,” the new paper recounts, “who regularly hunt and grill them over small fires.” Imagine a marshmallow roast, except the marshmallows are mouse-size bats devoured by protein-hungry children.
Picture of a hollow tree near the village of Méliandou, Guinea
Emile Ouamouno, the first to die in the current Ebola outbreak, may have been infected by bats while playing in this hollow tree near his village of Méliandou, Guinea.
The researchers then uncovered another clue: a large hollow tree, which had recently been set afire, producing as it burned what someone recalled as “a rain of bats.” Leendertz’s team collected soil samples at the base of that tree, which eventually yielded traces of DNA assignable to Mops condylurus, commonly called the Angolan free-tailed bat.

That species matched the villagers’ descriptions of lolibelo. What’s more, the big hollow tree had reportedly been a favorite play spot for small children of the village, including the deceased little boy, despite—or perhaps because of—the fact that it was full of little bats.

Too Close for Comfort?

All this is circumstantial evidence, pointing to a possibility that Ebola 2014 began when the boy in Méliandou came in contact with an Angolan free-tailed bat.

Bats of that species have previously been found to contain antibodies against Ebola virus, but the sample numbers were very small, and antibodies are weak evidence. The species has therefore not been included among the prime suspects as a reservoir for Ebola. That could change, if further sampling of Angolan free-tailed bats reveals any stronger data connecting the bat and the virus.
Picture of Fabian Leendertz, one of a team of scientists who identified a bat species that may host Ebola virus
Scientists identified a bat species that may host Ebola virus by analyzing DNA in soil and ash. The material was collected from around a tree that had held bats near the site of the first known human case in Guinea. Shown above is Fabian Leendertz, who led the science team, dissecting a bat.
The new paper is intriguing and suggestive—but is it important?

“Could be,” says Charles Calisher, emeritus professor at Colorado State University and an authority on zoonotic viruses, “if they would follow up with more studies.”

Leendertz and colleagues have already followed up, with extensive bat sampling in villages in Ivory Coast, Guinea’s neighbor to the southeast. Laboratory results from those samples, available soon, may suggest whether Mops condylurus is a hot lead in the long search for Ebola’s hiding place—or just another enticing dead end.
Picture of the small village of Méliandou, the first area hit in the current Ebola virus outbreak
The small village of Méliandou, shown, was the first area hit in the current Ebola virus outbreak.
If the lab data do implicate this bat species, then a disquieting question arises: Why aren’t there more spillovers of Ebola virus into humans—outbreaks beginning every month, every week?

The Angolan free-tailed bat is a forest creature that has become a village creature; as the great trees (including the hollow trees, like that one in Méliandou) have been felled, replaced by clearings and gardens and settlements, the bat has been forced to adapt. It has become synanthropic, closely associated with humans. Now it roosts in the hundreds beneath the thatch and metal roofs of village houses, just overhead as people eat and sleep.

Is Ebola that close too? If so, we’ve got still more to learn about this lethal, mysterious virus: not just where it hides and how it gets into humans, but why sometimes it lurks without leaping.
Picture of Etienne Ouamouno, father of the first victim of the current Ebola virus outbreak
Etienne Ouamouno sits in a communal room in Méliandou, Guinea. His son Emile is thought to have been the first to die in the current Ebola outbreak in December 2013.
David Quammen’s most recent book is Ebola: The Natural and Human History of a Deadly Virus. You can follow him on Twitter at @DavidQuammen.

http://news.nationalgeographic.com/news ... voir-host/


PostPosted: Wed Dec 31, 2014 12:34 am 

Joined: Wed Aug 19, 2009 10:42 am
Posts: 56044
Location: Pittsburgh, PA USA
Exclusive Video: Where the Ebola Outbreak Began
December 29, 2014, 3:04 pm ET by Jason M. Breslow
Email thisE-MAIL THIS 0
It was Christmas Day, 2013, when a one-year-old boy in Meliandou village, deep in the jungles of Guinea, fell ill.

“He had a fever, his body was hot,” recalled his father, Etienne Ouamouno. “He was shivering. When we gave him soup, he started vomiting.”

Three days later, Emile was dead, the first suspected victim of an Ebola outbreak that little more than a year later has devastated West Africa, infected more than 19,000 people across nine nations and killed more than 7,500.

But in Meliandou last Christmas, no one suspected Ebola. All people knew was that a mysterious illness was spreading through town.

Within days of Emile’s passing, his sister, Philomene, also grew sick and died. Then her mother, as well as her unborn child. Three women came to clean the family home. Soon after, they too were all dead.

Related: For a fleeting moment last spring, the Ebola epidemic sweeping West Africa might have been stopped. But efforts to control the virus, which has caused 7,500 deaths, fell short. Read more on How Ebola Roared Back from The New York Times
Maybe it was malaria, some thought. Maybe it was cholera?

“People were saying, ‘It must be the evil eye. Someone came with curses and is killing the people here,'” said Augustine Momodouno, the local nurse who first treated the family.

Filmmaker Dan Edge traveled to Meliandou to learn how residents initially responded for a film about the Ebola epidemic that will air on FRONTLINE this spring.

Amid the confusion and fear, Edge found, locals did what health experts warn not to do in the event of an outbreak: Rather than isolate the sick, they mixed the healthy and the ill in the center of the village, and gathered together for a traditional healing ceremony.

Watch: Ebola’s Patient Zero

But the ceremony didn’t work. One of the next to get sick was Emile’s grandmother, and when she left the village to seek treatment, the virus was officially on the move.

By March, the deadly disease had traveled to the town of Macenta — a distance of roughly 60 miles — killing more than 50 people along the way. Yet explanations were still lacking. In a race for answers, the Ministry of Health dispatched Dr. Lamine Koivogui, director of the Guinea Institute of Public Health, and a team of medics to investigate the infection of a boy named Khalil.

By the time the team found him, Khalil was bleeding profusely and near the point of death. As Koivogui remembered: “The clinician who was with me said: ‘I have seen a lot of diseases Dr. Lamine. But this one is a first.'”

Watch: The Virus Hunter

Koivogui initially suspected a hemorrhagic fever. “I never thought it could be Ebola,” he said. Within days, though, a blood sample from Khalil would come back positive from a lab in France. Health officials now had their answer, but the start of the Ebola outbreak, the worst on record, was only beginning.

http://www.pbs.org/wgbh/pages/frontline ... eak-began/


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