Showing posts with label ape. Show all posts

Thursday 23 September 2010

Cerebral malaria may have passed

22 September 2010 Last updated at 18:13

Cerebral malaria may have passed from gorillas to us

By Katie Alcock Science reporter, BBC News

Gorillas may be the source of human cerebral malaria

Humans may have originally caught malaria from gorillas, scientists say.

Until now, it was thought that the human malaria parasite split off from a chimpanzee parasite when humans and chimpanzees last had a common ancestor.

But researchers from the US, three African countries, and Europe have examined malaria parasites in great ape faeces.

They found the DNA from western gorilla parasites was the most similar to human parasites.

Cerebral malaria

Malaria is caused by a parasite called Plasmodium, and is carried by mosquitoes.

The most common species found in Africa, Plasmodium falciparum, causes dangerous cerebral malaria. Over 800,000 people die from malaria each year in the continent.

Until now, scientists had assumed that when the evolutionary tree of humans split off from that of chimpanzees - around five to seven million years ago - so had Plasmodium falciparum.

This would have meant that humans and malaria co-evolved to live together. But new evidence suggests human malaria is much newer.

Dr Beatrice Hahn of the University of Birmingham, Alabama, in the US, is part of a team that had been studying HIV and related infections in humans and great apes.

Cerebral malaria kills nearly a million people in Africa every year

DNA analysis

To study the DNA of infections in wild apes, you cannot use blood samples. So the team collected 2,700 samples of faecal material from two species of gorilla - western and eastern - and from common chimpanzees and bonobos, also known as pygmy chimpanzees.

They tried sequencing Plasmodium DNA from the faeces with techniques that use a large sample, and drew a genetic family tree to see which parasites were related. Dr Hahn said "When we did conventional sequencing, the tree didn't make any sense, because each sample contained a mixture of parasites."

They diluted the DNA so that they had just one parasite's genome represented in a single sample, and then amplified the DNA from there. This means they were able to separate the DNA from different species of the parasite much more effectively.

They then found the tree made much more sense. But they also found some surprising results.

The human Plasmodium was not very closely related to chimpanzee Plasmodium, as had been thought - but it was very closely related to one out of three species of gorilla Plasmodium from western gorillas in Central and West Africa.

There was more genetic variety in the gorilla parasites than in human parasites, and Dr Hahn said this means the gorilla is likely to be the "reservoir" - the origin of the human parasite.

"Other studies have just looked at chimps, so didn't find the gorilla parasite," said Dr Hahn. She added that some studies have looked at animals in captivity - so it is possible any parasites have "jumped" from their human keepers.

“Start Quote

Other studies have just looked at chimps, so didn't find the gorilla parasite”

End Quote Dr Beatrice Hahn University of Birmingham, Alabama, US

Cross-infection

The researchers, who report their findings in Nature, are now going to investigate further to see exactly how different the gorilla and human parasites are. Dr Hahn says that it is possible they are even the same species, and that cross-infection between humans and gorillas may be going on now.

Members of the team Dr Martine Peeters and Dr Eric Delaporte of the University of Montpelier in France are working with hunters and loggers in Cameroon, who spend a lot of time in the forests.

They will investigate whether these workers carry malaria parasites from the gorillas, which would suggest that new infections from other species can still happen.

They also do not yet know how badly apes are affected by malaria. Dr Hahn said that the team would now like to find out whether apes are able to catch the malaria parasite, without getting ill or dying in the way that humans do.

Friday 18 June 2010

Ape hunters pick up new viruses

Ape hunters pick up new viruses

Chimpanzees carry viruses which can jump to humans
Two new viruses from the same family as HIV have been discovered in central Africans who hunt nonhuman primates.
Researchers say their work proves it is not unusual for potentially dangerous viruses to jump from primates to man.

They say it is important to monitor disease in bushmeat hunters closely, as any virus they contract from animals may spread to the community at large.

The study, led by the US Johns Hopkins University, is published in Proceedings of the National Academy of Sciences.

Far from being rare events, retroviruses are actively crossing into human populations

Dr Nathan Wolfe
The new viruses identified in the latest study come from a group known as the retroviruses, which are known to cause serious illnesses in humans.

They have been named Human T-lymphotropic Virus types 3 and 4 (HTLV-3 and HTLV-4).

Humans have previously been infected by HTLV-1 and HTLV-2. In most cases, infection does not produce symptoms, but it can trigger neurological problems, and even leukaemia.

Lead researcher Dr Nathan Wolfe said: "The emergence of HIV from primate origins has cost millions of lives.

"The discoveries of HTLV-3 and HTLV-4 show that, far from being rare events, retroviruses are actively crossing into human populations."

Blood samples

The research team collected and examined blood samples from more than 900 people living throughout Cameroon.

All the individuals studied reported some exposure to blood and body fluids of nonhuman primates, contact mostly due to hunting and butchering of bushmeat, and in some cases to keeping primates as pets.

Analysis of the blood samples showed that various simian (ape) viruses had infected the participants.

The two previously unknown viruses were found in two bushmeat hunters.

HTLV-3 is similar to a simian virus called STLV-3, and was most likely contracted through direct contact with a primate during hunting.

HTLV-4 does not have a known primate counterpart, making its origin less clear. The researchers believe it could have arisen through cross-species transmission from an animal carrying an unknown form of STLV.

The same team discovered another primate retrovirus - the simian foamy virus (SFV) - in bushmeat hunters last year.

Threat unclear

At this stage it is unclear whether either of the two newly discovered viruses or SFV are harmful to humans, or can be transferred from person to person.

However, the researchers say their work clearly shows that hunting provides the opportunity for viruses to jump the species barrier.

Dr Wolfe said: "Ongoing collaboration with hunters in central Africa gives us the potential to predict and prevent disease emergence.

"Given the incredible potential costs of a new human retrovirus spreading into the general population, the development of sentinel systems for forecasting disease emergence - such as long-term surveillance of hunters - should be seen as a human health imperative."

Dr Deenan Pillay, an expert in virology at University College London, UK, told the BBC News website that it had been thought few viruses jumped the species barrier.

"This research suggests that there seems to be far more transmission of a whole range of primate viruses into humans than was previously thought," he said.

"But that is not alarming in its own right. If the virus fails to replicate, or to be passed on to others, then it does not pose a threat.

"However, if cross-species transmission is such a frequent event, then all it takes is for one virus to really take hold in somebody, and be passed on to others for it to take off in humans."

Tuesday 27 April 2010

She's been rearing a small group of apes as if they are people, to see what happens.

Chimps 'are people, too'

By Dick Taylor
BBC Horizon

Danny Wallace investigates for Horizon

In a private facility just outside Des Moine, Iowa , primatologist Sue Savage-Rumbaugh is conducting an experiment that has lasted 26 years.

She's been rearing a small group of apes as if they are people, to see what happens.

Her results appear to be spectacular, at least to writer Danny Wallace: "Kanzi asked me for a present. I gave him the free toothbrush kit from my flight over. He brushed his teeth. We bonded."

Danny is a seasoned television campaigner: he showed us How To Start Your Own Country on BBC Two last year.

You could say that an adult chimp has more of the characteristics of a person than a new born baby

Julian Baggini, philosopher

As a non-scientist, he's a useful man to investigate the extent to which our closest relatives, the chimpanzees, could indeed be people, too. Because, at the heart of primate research, there is a conundrum.

Many primatologists are devising experiments that show chimps are ever more people-like than was thought just a few years ago; and yet, as scientists, they will not countenance that chimps could ever be people.

Yes and no

At the Yerkes Primate Centre in Atlanta, Danny finds out from researcher Victoria Horner that chimps have culture...

Victoria: "This experiment is the first definite evidence that chimpanzees can pass on ideas to each other. That is the basis of culture."

Danny: "So, are they people then?"

Victoria: "No."

In Budongo National Park, Uganda. Katie Slocombe from St Andrews University is studying vocalisations with wild chimps...

Katie: "Chimps produce an incredibly wide range of sounds. It appears that they may have a rudimentary language."

Danny: "So, are they people then?

Katie: "No"

Alicia Melis of the Max Planck Institute in Leipzig conducts experiments to see if chimps have a quintessential human character, one that was thought to be absent till now: co-operation...

Alicia: "Chimps can co-operate, they can even chose the best co-operator to help them when presented with a range of their mates."

Danny: "...they co-operate, they're people?

Alicia: "Sort of!"

Researchers continue to find more and more human-like behaviours

Now, Danny's bluff character and native wit carry him through these encounters, but there is a good reason why he persists in asking these seemingly crazy questions.

According to philosopher Julian Baggini, it is possible that non-human animals like chimps could be people.

"You could say that an adult chimp has more of the characteristics of a person than a new born baby," he says.

After all, though humans and chimps are different species, they share up to 99.4% of their most crucial DNA (the figure is difficult to calculate exactly and depends on the scientist you speak to). And to prove how similar we are to chimps, Danny takes part in a potentially humiliating experiment.

The scent of male sweat is controlled by their genes, in both chimps and men. In a blind test, three women were asked to sniff the sweat of Danny and Cody the chimp, to see which one they fancied most.

When they found out afterwards that one of the odours was from a chimp, there was laughter. When they realised that two out of three had preferred the chimp, there was nervous laughter.

'Learning key'

When Danny finally reaches Des Moines, the issue comes into focus.

The chimp and human genomes are very, very close

The apes Sue Savage Rumbaugh works with - and lives with - are bonobos. They are a kind of chimpanzee that is less aggressive than that found in most zoos.

Having brushed his teeth Kanzi, a 26-year-old bonobo, built like a heavyweight boxer and who is five times stronger than an average man, looks into Danny's eyes and asks him to play "Chase".

So they hang out together for a while, because that's what Kanzi has learned to do. And for Sue Savage Rumbaugh, learning is the key.

"Take a human child. If you lock him into a cage, never take him to the mall, never give him ice-cream, never teach him to communicate - how could he become a person?" asks Sue.

Chimps are human? Never. Chimps are people? You decide.

Horizon: Chimps Are People Too is on BBC Two at 2100 BST on Tuesday 10 October. Watch video highlights at Horizon's website.

Sunday 7 February 2010

Bonobos need your love

Bonobos need your love this Valentine's Day! These compassionate, peaceful great
apes are still struggling for survival in many areas of their habitat -- and they
need our help now more than ever! Hunting and habitat destruction, primarily from
logging, continue to threaten bonobos and their rainforest home.
Show someone special how much you care by adopting a bonobo in their name. Your
contribution will go directly toward efforts to create new protected areas to safeguard
bonobos, to rescue bonobos that have been orphaned or captured, and to support dedicated
eco-guards and monitoring teams


Bonobos
are humankind's closest relatives, along with chimpanzees, yet most people don't even know that bonobos exist! They live only in one country: the Democratic Republic of Congo (DRC). Bonobos were last great ape species to be discovered, and could be the first to go extinct if we do not act quickly to save them and their rainforest home. Bonobos stand apart from the other great apes in fascinating and important ways. But perhaps the most compelling aspect of bonobos is their society

Saturday 7 November 2009

world's primates says 48% of species face extinction,

Primates 'face extinction crisis'

By Mark Kinver
Science and nature reporter, BBC News

Under pressure: The Critically Endangered grey-shanked douc langur is one of the primates in peril

A global review of the world's primates says 48% of species face extinction, an outlook described as "depressing" by conservationists.

The IUCN Red List of Threatened Species says the main threat is habitat loss, primarily through the burning and clearing of tropical forests.

More than 70% of primates in Asia are now listed as Endangered, it adds.

The findings form part of the most detailed survey of the Earth's mammals, which will be published in October.

PRIMATES IN PERIL

Nations with the highest percentage of threatened species:

Cambodia - 90%

Vietnam - 86%

Indonesia - 84%

Laos - 83%

China - 79%

(Source: IUCN Red List)

Other threats include hunting of primates for food and the illegal wildlife trade, explained Russell Mittermeier, chairman of global conservation group IUCN's Primate Specialist Group and president of Conservation International.

"In many places, primates are quite literally being eaten to extinction," he warned.

"Tropical forest destruction has always been the main cause, but now it appears that hunting is just as serious a threat in some areas, even where the habitat is still quite intact."

The survey, involving hundreds of experts, showed that out of 634 recognised species and subspecies, 11% were Critically Endangered, 22% were Endangered, while a further 15% were listed as Vulnerable.

Asia had the greatest proportion of threatened primates, with 71% considered at risk of extinction. The five nations with the highest percentage of endangered species were all within Asia.

'Depressing' picture

"It is quite spectacular; we are just wiping out primates," said Jean-Christophe Vie, deputy head of the IUCN Species Programme.

RED LIST DEFINITIONS

Tonkin snub-nosed monkey (Image: Tilo Nadler)

The Tonkin snub-nosed monkey is listed as Critically Endangered

Extinct - Surveys suggest last known individual has died

Critically Endangered - Extreme high risk of extinction - this means some Critically Endangered species are also tagged Possibly Extinct

Endangered - Species at very high risk of extinction

Vulnerable - Species at high risk of extinction

Near Threatened - May soon move into above categories

Least Concern - Species is widespread and abundant

Data Deficient - not enough data to assess

He added that the data was probably the worst assessment for any group of species on record.

"The problem with these species is that they have long lives, so it takes time to reverse the decline. It is quite depressing."

Although habitat loss and deforestation were deemed to be the main threats globally, Dr Vie explained how human encroachment into forests was also creating favourable conditions for hunters.

"This creates access, allowing people to go to places that they could not go in the past," he told BBC News.

"Primates are relatively easy to hunt because they are diurnal, live in groups and are noisy - they are really easy targets.

"Many of the Asian primates, like langurs, are 5-10kg, so they are a good target. Generally, you find that what is big and easy to get disappears very quickly."

In Africa, 11 of the 13 kinds of red colobus monkeys assessed were listed as Critically Endangered or Endangered.

Conservationists fear that two may already be extinct. The Bouvier's red colobus has not been seen for 25 years, and no living Miss Waldron red colobus has been recorded since 1978.

The authors of the primate Red List did consider downlisting mountain gorillas to Endangered from Critically Endangered because the great apes had recorded a population increase.

But they decided to delay reclassification as a result of five of the gorillas being killed in July 2007 by gunmen in the DR Congo's Virunga National Park, which is still at the centre of a conflict between rebel forces and government troops.

During 2007, wildlife rangers in the park recorded a total of 10 gorilla killings. The rangers have been documenting their struggles in a regular diary on the BBC News website over the past year.

Mountain gorilla (Image: WildlifeDirect)

Mountain gorillas have been caught in the crossfire of a land dispute

Diary: Protecting mountain gorillas

"If you kill seven, 10 or 20 mountain gorillas, it has a devastating impact on the entire population," Dr Vie explained.

"Within the Red List criteria, you are allowed to anticipate what will happen in the future as well as look at what has happened in the past.

"So it was decided not to change the mountain gorillas' listing because of the sudden deaths, and we do not know when it is going to stop."

Dr Emmanuel de Merode, chief executive of Gorilla.cd - an EU-funded programme working in Virunga National Park - said the gorillas' long-term survival was still far from assured.

"Militias have been in control of the Gorilla Sector since September last year, which means the Congolese wildlife authority has been unable to manage the area and protect the gorillas," he told BBC News.

"Until the war ends and the rangers are able to get back in and patrol the area, we have no idea as to the fate of almost a third of the mountain gorillas left in the world."

Golden glimmer of hope

Despite the gloomy outlook, the Red List did record a number of conservation successes.

Golden lion tamarin (Image: CI/Russell Mittermeier)

The re-introduction of golden lion tamarins is one of the few successes

Brazil's populations of golden lion tamarins and black lion tamarins were downlisted from Critically Endangered to Endangered.

"It is the result of decades of effort," said Dr Vie. "The lion tamarins were almost extinct in the wild, but they were very popular in zoos so there was a large captive population.

"So zoos around the world decided to join forces to introduce a captive breeding programme to reintroduce the tamarins in Brazil."

However the first attempts were not successful and the released population quickly crashed because the animals were ill-prepared for life in the wild, he recalled.

"They were not exposed to eagles or snakes and they did not know how to find food, so a lot of them died. But some did survive and, slowly, the numbers began to increase."

Ultimately, the success was a combination of ex-situ conservation in zoos and in-situ conservation by protecting and reforesting small areas around Rio de Janeiro and Sao Paulo.

"It took time, money and effort at all levels, from the politicians to scientists and volunteers on the ground, for just two species."

The findings, issued at the International Primatological Society Congress in Edinburgh, Scotland, will be included in a survey described as an "unprecedented examination of the state of the world's mammals", which will be presented at the IUCN World Conservation Congress in October.

Wednesday 30 September 2009

MAKE LOVE, NOT WAR!

The bonobo credo: MAKE LOVE, NOT WAR!

worst threat to bonobo survival is instability in its homeland, the Democratic Republic of Congo (DRC). Between 1996 and 2003, war and foreign occupation ravaged the DRC, killing more than 4 million people, more than any conflict since WWII. Today a fragile peace is in place, and the DRC is currently holding its first democratic elections in over 40 years since the colonial era.

Bonobos stand as a flagship, not only for conservation of the Congo rainforest, but also for Peace in the DRC - and globally. Bonobos exemplify how society can be successfully organized through cooperation and sharing of resources, as opposed to competition, territoriality and violence (as demonstrated by our other closest primate relatives, the male-dominated chimpanzees). Further, bonobos show how love - and love-making - can ease tensions and keep the peace.

The recent warfare and decades of corruption under the Mobutu regime before that have hobbled the DRCÃ s efforts to exploit its great wealth for the people of the Congo and have devastated habitat for man and animals. Forests are being depleted as more and more people hunt bushmeat (including the great apes), both for sustenance and for sale in the commercial trade. As competing parties search for peace - and a piece of the pie - the vast ecosystems of the Congo Forest and the prospects for a safe and sustainable future for the Congolese people hang in the balance.

The Congo War was fueled by illegal exploitation of natural resources, such as coltan, gold, diamonds, copper, cobalt, and timber. Thus, a vital key to lasting peace is wise and equitable management of natural resources. To this end, the Bonobo Conservation Initiative, local Congolese partners and communities, the government of the DRC, and other international partners are creating theBonobo Peace Forest - a large, multi-zoned protected area consisting of a linked constellation of community-based reserves, supported by sustainable development, in the heart of the bonobo habitat.

Click here to learn more about the Bonobo Peace Forest.

For more information about the DR Congo and current news, see:

Ebola haemorrhagic fever

Ebola virus belongs to the Filoviridae family (filovirus) and is comprised of five distinct species: Zaïre, Sudan, Côte d’Ivoire, Bundibugyo and Reston.
Zaïre, Sudan and Bundibugyo species have been associated with large Ebola hemorrhagic fever (EHF) outbreaks in Africa with high case fatality ratio (25–90%) while Côte d’Ivoire and Reston have not. Reston species can infect humans but no serious illness or death in humans have been reported to date.
Human infection with the Ebola Reston subtype, found in the Western Pacific, has only caused asymptomatic illness, meaning that those who contract the disease do not experience clinical illness. The natural reservoir of the Ebola virus seems to reside in the rain forests of the African continent and in areas of the Western Pacific.

Transmission

The Ebola virus is transmitted by direct contact with the blood, secretions, organs or other body fluids of infected persons.
Burial ceremonies where mourners have direct contact with the body of the deceased person can play a significant role in the transmission of Ebola.
The infection of human cases with Ebola virus through the handling of infected chimpanzees, gorillas, and forest antelopes -- both dead and alive -- has been documented in Côte d'Ivoire, the Republic of Congo and Gabon. The transmission of the Ebola Reston strain through the handling of cynomolgus monkeys has also been reported.
Health care workers have frequently been infected while treating Ebola patients, through close contact without correct infection control precautions and adequate barrier nursing procedures.

Incubation period: two to 21 days.

Symptoms

Ebola is characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is often followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Laboratory findings show low counts of white blood cells and platelets as well as elevated liver enzymes.

Diagnosis

Specialized laboratory tests on blood specimens detect specific antigens and/or genes of the virus. Antibodies to the virus can be detected, and the virus can be isolated in cell culture. Tests on samples present an extreme biohazard risk and are only conducted under maximum biological containment conditions. New developments in diagnostic techniques include non-invasive methods of diagnosis (testing saliva and urine samples) and testing inactivated samples to provide rapid laboratory diagnosis to support case management during outbreak control activities.

Therapy and vaccine

Severe cases require intensive supportive care, as patients are frequently dehydrated and in need of intravenous fluids or oral rehydration with solutions containing electrolytes.
No specific treatment or vaccine is yet available for Ebola haemorrhagic fever. Several potential vaccines are being tested but it could be several years before any is available. A new drug therapy has shown some promise in laboratory studies and is currently being evaluated. But this too will take several years.
Experimental studies using hyper-immune sera on animals have shown no protection against the disease.

Containment

Suspected cases should be isolated from other patients and strict barrier nursing techniques implemented.
Tracing and following up people who may have been exposed to Ebola through close contact with patients are essential.
All hospital staff should be briefed on the nature of the disease and its transmission routes. Particular emphasis should be placed on ensuring that invasive procedures such as the placing of intravenous lines and the handling of blood, secretions, catheters and suction devices are carried out under strict barrier nursing conditions. Hospital staff should have individual gowns, gloves, masks and goggles. Non-disposable protective equipment must not be reused unless they have been properly disinfected.
Infection may also spread through contact with the soiled clothing or bed linens from a patient with Ebola. Disinfection is therefore required before handling these items.
Communities affected by Ebola should make efforts to ensure that the population is well informed, both about the nature of the disease itself and about necessary outbreak containment measures, including burial of the deceased. People who have died from Ebola should be promptly and safely buried.

Contacts

As the primary mode of person-to-person transmission is contact with contaminated blood, secretions or body fluids, people who have had close physical contact with patients should be kept under strict surveillance. Their body temperature should be checked twice a day, with immediate hospitalization and strict isolation in case of the onset of fever.
Hospital staff who come into close contact with patients or contaminated materials without barrier nursing attire must be considered as contacts and followed up accordingly.

History

The Ebola virus was first identified in a western equatorial province of Sudan and in a nearby region of Zaïre (now the Democratic Republic of the Congo) in 1976 after significant epidemics in Yambuku in northern Democratic Republic of the Congo, and Nzara in southern Sudan.

Between June and November 1976, the Ebola virus infected 284 people in Sudan, causing 151 deaths. In the Democratic Republic of the Congo, there were 318 cases and 280 deaths in September and October. An isolated case occurred in the Democratic Republic of the Congo in 1977, and there was another outbreak in Sudan in 1979 (33 cases, including 22 deaths).
In 1989, Reston, an Ebola virus subtype, was isolated in quarantined laboratory cynomolgus monkeys (Macacca fascicularis) in Reston, Virginia, USA. From 1989 to 1996, several outbreaks caused by the Ebola Reston subtype occurred in monkeys imported from the Philippines to the USA (Reston in Virginia, Alice in Texas and Pennsylvania) and to Italy. Investigations traced the source of all Ebola Reston outbreaks to one export facility near Manila in the Philippines, but the mode of contamination of this facility was not determined. Several monkeys died, and at least four people were infected, although none of them suffered clinical illness.
One human case of Ebola haemorrhagic fever of the Cote d'Ivoire subtype and several cases in chimpanzees were confirmed in Côte d'Ivoire in November 1994.
A large epidemic occurred in Kikwit, the Democratic Republic of the Congo in 1995 with 315 cases, 250 of whom died.
In Gabon, Ebola haemorrhagic fever was first documented in 1994 (19 cases including 9 deaths). Successive outbreaks occurred in February (37 cases including 21 deaths) and July of 1996 (60 cases including 45 deaths).
In October 2000, Ebola was reported in Gulu district in northern Uganda. Between September 2000 and January 2001, the Sudan subtype of the Ebola virus infected 425 cases, including 224 deaths, making this the largest epidemic so far documented of Ebola. This was the first reported emergence of the Sudan Ebola virus since 1979.
From October 2001 to December 2003, several Ebola outbreaks of the Zaïre subtype were reported in Gabon and the Republic of the Congo with a total of 302 cases and 254 deaths.

About 1850 cases with over 1200 deaths have been documented since the Ebola virus was discovered.

Natural reservoir

The natural reservoir of the Ebola virus is unknown despite extensive studies, but it seems to reside in the rain forests on the African continent and in the Western Pacific.
Although non-human primates have been a source of infection for humans, they are not thought to be the reservoir. They, like humans, are believed to be infected directly from the natural reservoir or through a chain of transmission from the natural reservoir.
On the African continent, Ebola infections of human cases have been linked to direct contact with gorillas, chimpanzees, monkeys, forest antelope and porcupines found dead in the rainforest. So far, the Ebola virus has been detected in the wild in carcasses of chimpanzees (in Côte-d’Ivoire and the Republic of the Congo), gorillas (Gabon and the Republic of the Congo) and duikers (the Republic of the Congo).
Different hypotheses have been developed to explain the origin of Ebola outbreaks. Laboratory observation has shown that bats experimentally infected with Ebola do not die, and this has raised speculation that these mammals may play a role in maintaining the virus in the tropical forest.
Extensive ecological studies are under way in the Republic of the Congo and Gabon to identify the Ebola's natural reservoir

Primates 'face extinction crisis