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Chimpanzees and monkeys have entered the Stone Age

Posted date: 11:55 PM / comment : 0 ,

“Some Chimpanzees Have Entered Stone Age.” Scientists On 3 Continents Make Surprising Discovery.

In the rainforests of west Africa, the woodlands of Brazil and the beaches of Thailand, archaeologists have stumbled upon some fascinating stone tools.
What sets them apart is not the workmanship or their antiquity: they belong to the same age as the Egyptian pyramids.

Source

What is exceptional about this discovery is that the tools were held by non-human hands.

The tools are crude. A chimpanzee or monkey stone hammer is hardly a work of art to rival the beauty of an ancient human hand axe. But that’s not the point. These primates have developed a culture that makes routine use of a stone-based technology. That means they have entered the Stone Age.
The chimpanzees of west Africa had used these tools in a cruder way, to crack open nuts for example.
A few years ago, biologists believed only humans could make extensive use of tools. However, recent discovery falsifies this claim.Our closest living relatives might be similar to us, more than we could have ever imagined. An article published in Oxford journals suggests monkeys and chimpanzees have a flair for reading each other’s facial expressions. This certainly calls for a re-assessment of primates. 

Countries like New Zealand and the United Kingdom consider experiments on apes, illegal. Spain for example, allots them some human rights. In the U.S. too, there are reforms taking place in this area. A trial pending in New York courts wants chimpanzees to be granted full human rights.
If nothing else, we should certainly be compassionate and sympathetic to our primate cousins.


For Further Reading

How many trees are there in the world?

Posted date: 8:27 AM / comment : 0 , , , ,

According to a new study, the answer is somewhere around 3.04 trillion.
That's about 400 trees for every person.
12,000 years ago, before the advent of agriculture, Earth had twice as many trees as it does now. Currently, our planet is losing 10 million trees a year.
"We used ground-sourced information," says Crowther. "All of the information that went into our models was generated from people standing on the ground counting numbers of trees in a given area. And so we could relate this information to what the satellites are telling us."
Previous estimates of the Earth's tree population put the number at 400.25 billion. That’s nearly an order of magnitude less than the new tally. Scientists say the discrepancy has to do with how the two estimates were calculated.
“Satellite images can tell you a lot about the forest area and canopy cover,” Crowther said. “What we provide is a more detailed understanding of what is going on beneath the surface.”
The new study incorporates satellite imagery, but it also relies on 429,775 ground-based measurements of tree density made by an actual person who counted the number of trees in a given area.
"We all gathered in a room, it was a very exciting time," remembers Crowther. "We'd been working toward it for two years."

The result: A staggering three trillion trees.

Researchers represented the number of trees across the globe using bars that are taller for denser forests.


Crowther added that one of the most dominant themes of the study is how large an effect humans are having on the tree population on the planet.

“Human activity came out as the strongest control on tree density across all biomes,” he said. “It really highlights how big of an impact humans are having on the Earth on a global scale.”


Researchers have developed a new strain of GM tomatoes that can efficiently produce some natural disease-fighting compounds such as Resveratrol (one tomato can produce an equivalent amount as fifty bottles of red wine)

Posted date: 9:10 PM / comment : 0 ,

Abstract

Phenylpropanoids comprise an important class of plant secondary metabolites. A number of transcription factors have been used to upregulate-specific branches of phenylpropanoid metabolism, but by far the most effective has been the fruit-specific expression of AtMYB12 in tomato, which resulted in as much as 10% of fruit dry weight accumulating as flavonols and hydroxycinnamates. We show that AtMYB12 not only increases the demand of flavonoid biosynthesis but also increases the supply of carbon from primary metabolism, energy and reducing power, which may fuel the shikimate and phenylalanine biosynthetic pathways to supply more aromatic amino acids for secondary metabolism. AtMYB12 directly binds promoters of genes encoding enzymes of primary metabolism. The enhanced supply of precursors, energy and reducing power achieved by AtMYB12 expression can be harnessed to engineer high levels of novel phenylpropanoids in tomato fruit, offering an effective production system for bio actives and other high-value ingredients.

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Explanation

One genetically modified tomato holds the same amount of Resveratrol as fifty bottles of red wine
The tomato has been a symbol for genetically modified food for many years. In 1994, genetically modified tomatoes hit the market in the US as the first commercially available genetically modified crop. GM tomatoes have since disappeared. (Source)
One genetically modified tomato holds the same amount of Resveratrol as fifty bottles of red wine


Resveratrol is a member of the  phenylpropanoids; an antioxidant found in grapes (when processed also in red wine), which has been reported to increase the lifespan of animals in certain animal studies. It may also be an effective supplement to fight cancer, heart conditions, Alzheimer’s disease and diabetes, but these claims are yet to be scientifically proven as there are still mixed opinions on the effects of Resveratrol. The researchers have been able to produce a tomato that has the equivalent amount of Resveratrol as fifty bottles of red wine.

These findings have been published in the journal Nature Communications in a paper titled: “Multi-level engineering facilitates the production of phenylpropanoid compounds in tomato”.

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What's so good about the GM tomatoes?


  • One GM tomato contains as much of the grape compound resveratrol as 50 bottles of red wine. This is also found in berries and peanuts and is thought to protect the heart and lower cholesterol.
  • They also produce the same amount of genistein as 2.5 kilograms of tofu. Genistein may help prevent breast cancer.
  • "Medicinal plants with high value are often difficult to grow and manage, and need very long cultivation times to produce the desired compounds.
  • Our research provides a fantastic platform to quickly produce these valuable medicinal compounds in tomatoes. Target compounds could be purified directly from tomato juice.
  • We believe our design idea could also be applied to other compounds such as terpenoids and alkaloids, which are the major groups of medicinal compounds from plants." (Source)
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The protein AtMYB12 is found in a very common U.K. garden plant, Arabidopsis thaliana; it plays an important role in controlling the production of natural compounds vital for the plant’s survival. As explained in a statement: “The protein acts a bit like a tap to increase or reduce the production of natural compounds depending on how much of the protein is present.”

The researchers introduced this protein into a tomato plant – remarkably, it increased the ability of the tomato to produce phenylpropanoids. In addition, it induced the plant into devoting more energy into the production of these natural compounds, including resveratrol. Putting it another way, this protein turned on the resveratrol “tap” at full blast.

All these benefits, of course, does not mean you should down as much red wine or scoff as much dark chocolate as possible – the high sugar content in wine will at the very least reverse the anti-diabetic effects the resveratrol appears to offer. As aforementioned, some studies conclude that this multi-purpose molecule actually has no effect on the health of humans, with no association made between a diet rich in resveratrol and a reduction in the incidence of cancers or heart disease. (Source)

You can sell your poop

Posted date: 6:38 AM / comment : 0

You can donate blood, plasma, eggs, and sperm. Why not poop? Yes, your feces are perhaps your greatest untapped monetary resource.Everybody poops. That’s not just the name of a popular potty training book, but it’s an essential fact of life. However, most people merely flush it away without a second thought. In the spirit of one man’s trash being another man’s treasure, the non-profit company OpenBiome is actually paying for stool samples in order to create lifesaving fecal transplant treatments for those infected with Clostridium difficile, a bacteria which is highly resistant to antibiotics.
Source

 Infections of C. difficile result in severe diarrhea, hospitalizing 250,000 Americans each year and causing about 14,000 deaths. It can actually come about after using antibiotics for too long, which ties into what makes it exceptionally difficult to treat. The patient’s gut microbiota is nearly wiped out, and conventional probiotics are not sufficient to replace them.
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Requirements for Donors

Caveat: 

You have to live within commuting distance from Boston and be in excellent health, especially as far as your fecal matter is concerned. Some other guidelines are
Types one or two, defined by the Bristol Stool Chart as “like nuts” or “lumpy,” are too dry to process into a treatment.

If a donor’s stool is “mushy” or “watery” — that’s a type six or seven — then it can’t be used because it could be a sign the donor has a gastrointestinal infection.
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The perfect poop is type three, which is “like a sausage but with cracks on its surface;” type four, which is “like a sausage or snake, smooth and soft;” or type five, “soft blobs with clear-cut edges (passed easily).” [Link 1, Link 2]

Over the last four years, only 4 percent of interested donors have passed the screening process, co-founder Mark Smith told WaPo. (Link) -->

Rate

The going rate is $40 per donation, with a $50 kicker for those who come five days a week. This translates into $250 per week, or $13,000 per year. OpenBiome tries to make the experience as fun as they can by offering prizes to donors who make the most donations, provide the biggest sample, etc. However, there’s no word on if OpenBiome offers a fun sticker to show off your donation to friends and family, such as the “Be nice to me, I gave blood today” badge handed out by the Red Cross.
 [Link 1, Link 2, Link 3]

Dolphins

Posted date: 8:25 AM / comment : 0

Dolphins are a widely distributed and diverse group of fully aquatic marine mammals. They are an informal grouping within the order Cetacea, excluding whales and porpoises, so to zoologists the grouping is paraphyletic. The dolphins comprise the extant families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the new world river dolphins), and Pontoporiidae (the brackish dolphins). There are 40 extant species of dolphins. Dolphins, alongside other cetaceans, belong to the clade Cetartiodactyla with even-toed ungulates, and their closest living relatives are the hippopotamuses, having diverged about 40 million years ago.
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Size

Dolphins range in size from the 1.7 metres (5.6 ft) long and 50 kilograms (110 lb) Maui's dolphin to the 9.5 metres (31 ft) and 10 metric tons (11 short tons) killer whale. Several species exhibit sexual dimorphism, in that the males are larger than females. They have streamlined bodies and two limbs that are modified into flippers.

Sleeping

Dolphins have to be conscious to breath. This means that they cannot go into a full deep sleep, because then they would suffocate. Dolphins have "solved" that by letting one-half of their brain sleep at a time. This has been determined by doing EEG studies on dolphins. Dolphins sleep about 8 hours day in this fashion. 
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A dolphin's behavior when sleeping/resting depends on the circumstances and possibly on individual preferences. They can either:
1. Swim slowly and surface every now and then for a breath
2. Rest at the surface with their blowhole exposed 
3. Rest on the bottom (in shallow water) and rise to the surface every now and then to breath. 
Sources
1. S.H Ridgway (1990) The Central Nervous System of the Bottlenose Dolphin, in S. Leatherwood and R.R. Reeves: The Bottlenose Dolphin, pp. 69-97, Academic Press
2. Mukhametov, L. M.; Supin, A. Ya. (1978). "Sleep and vigil in dolphins". Marine mammals. Moscow: Nauka.
3. Mukhametov, Lev (1984). "Sleep in marine mammals". Experimental Brain Research. Experimental Brain Research Supplementum. 8 (suppl.): 227–238. doi:10.1007/978-3-642-69554-4_17. ISBN 978-3-642-69556-8.
4. Dallas Grasby (1994). "Excerpts from "Sleep in marine mammals", L.M. Mukhametov". Experimental Brain Research. 8 (suppl.). Retrieved February 11, 2008. [Link]

Source

Intelligence

Brain size was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that mammalian brain size scales at approximately the ⅔ or ¾ exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an encephalization quotient that can be used as another indication of animal intelligence. Killer whales have the second largest brain mass of any animal on earth, next to the sperm whale. The brain to body mass ratio in some is second only to humans.
In 1995, Marten and Psarakos used television to test dolphin self-awareness. They showed dolphins real-time footage of themselves, recorded footage, and another dolphin. They concluded that their evidence suggested self-awareness rather than social behavior. While this particular study has not been repeated since then, dolphins have since passed the mirror test. [Source 1, Source 2, Source 3]
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Research Example
At the Institute for Marine Mammal Studies in Mississippi, Kelly the dolphin has built up quite a reputation. All the dolphins at the institute are trained to hold onto any litter that falls into their pools until they see a trainer, when they can trade the litter for fish. In this way, the dolphins help to keep their pools clean.

Kelly has taken this task one step further. When people drop paper into the water she hides it under a rock at the bottom of the pool. The next time a trainer passes, she goes down to the rock and tears off a piece of paper to give to the trainer. After a fish reward, she goes back down, tears off another piece of paper, gets another fish, and so on. This behaviour is interesting because it shows that Kelly has a sense of the future and delays gratification. She has realised that a big piece of paper gets the same reward as a small piece and so delivers only small pieces to keep the extra food coming. She has, in effect, trained the humans.
Then one day, Kelly managed to grab a gull that flew into the tank. When she delivered it to her keepers, she got an especially large fish reward. The next time Kelly was fed she hid the fish at the bottom of the pool, and later brought it to the surface to lure more gulls into the pool. The strategy proved so successful that she taught her offspring, who went on to teach others. (Source 1, Source 2, Source 3, Source 4)

Chimpanzees and monkeys have entered the Stone Age

Posted date: 3:11 PM / comment : 2 ,

“Some Chimpanzees Have Entered Stone Age.” Scientists On 3 Continents Make Surprising Discovery.

In the rainforests of west Africa, the woodlands of Brazil and the beaches of Thailand, archaeologists have stumbled upon some fascinating stone tools.
What sets them apart is not the workmanship or their antiquity: they belong to the same age as the Egyptian pyramids.
-->
Source

What is exceptional about this discovery is that the tools were held by non-human hands.

The tools are crude. A chimpanzee or monkey stone hammer is hardly a work of art to rival the beauty of an ancient human hand axe. But that’s not the point. These primates have developed a culture that makes routine use of a stone-based technology. That means they have entered the Stone Age.
The chimpanzees of west Africa had used these tools in a cruder way, to crack open nuts for example.
A few years ago, biologists believed only humans could make extensive use of tools. However, recent discovery falsifies this claim.
Our closest living relatives might be similar to us, more than we could have ever imagined. An article published in Oxford journals suggests monkeys and chimpanzees have a flair for reading each other’s facial expressions.
This certainly calls for a re-assessment of primates.
-->
Countries like New Zealand and the United Kingdom consider experiments on apes, illegal. Spain for example, allots them some human rights. In the U.S. too, there are reforms taking place in this area. A trial pending in New York courts wants chimpanzees to be granted full human rights.
If nothing else, we should certainly be compassionate and sympathetic to our primate cousins.


For Further Reading

Carrier Pigeon Faster Than Broadband Internet

Posted date: 2:33 PM / comment : 1 , ,

In South Africa, a carrier pigeon carrying a 4GB memory stick proved to be faster than the ADSL service from the country's biggest web firm, Telkom. Winston the pigeon took one hour and eight minutes to carry the data across the 60-mile course, and it took another hour to upload the data. During the same time, the ADSL had sent just 4% of the data.

--> The race was held by an IT company in Durban, South Africa, called Unlimited IT. One of Unlimited IT's employees complained about the slow speed of data transmission on ADSL, saying that data would get transferred faster by carrier pigeon. To highlight just how slow the broadband internet is, the company decided to test that claim.
Kevin Rolfe with Winston
Source

The 11-month-old Winston flew 60 miles from Unlimited IT's call center in Howick to another office in Durban. To make sure that the bird didn't have an unfair advantage, Unlimited IT imposed some rules on its website, including "no cats allowed" and "birdseed must not have any performance-enhancing seeds within." Hundreds of South Africans followed the race on social networking sites Facebook and Twitter.

--> For its part, Telkom said that it was not responsible for Unlimited IT's slow broadband speeds. A Telkom spokesperson said that they had made several recommendations to Unlimited IT to improve its service, but none of the suggestions had been accepted.

As the BBC reports, South Africa is one of the countries that could benefit from three new fiber optic cables being laid around the African continent to improve internet service. -->
For more information about the pigeon race visit the official website.

Sources

BBC NEWS
News24
Reuters
Wikipedia

For Fun





Psychologists have no idea how to rehabilitate sex offenders.

Posted date: 12:31 PM / comment : 0 ,

Prison programs that have been in place for decades to rehabilitate convicted sex offenders may not work at all, according to a new study.
Sex offender treatment programs — in which offenders follow a syllabus aimed at “normalizing” their sexual impulses and fantasies — have not been shown to reduce the likelihood that sex offenders will change their behavior after they get out of jail, forensic psychiatrist David K. Ho  in the BMJ medical journal.
Source

“No evidence from academic or policy research has shown that the treatment program significantly reduces sexual reoffending,” David K. Ho, a forensic psychologist at South Essex Partnership University in England, writes in BMJ. “Victims and the public deserve to know this.”

--> “Sex offenders are sent to prison, undergo this treatment program, are deemed to have been somewhat rehabilitated and are released to the public,” Ho wrote. “However, they are as likely to offend as before receiving treatment.”

In 2012, a major review of sex offender treatment programs concluded that for a regime that has been imposed on so many prisoners, there had not been nearly enough research proving its worth. No one has done studies rigorous enough to prove that it’s useless either, though — and that lack of data is a real problem. “Not only could this result in the continued use of ineffective (and potentially harmful) interventions, but it also means that society is lured into a false sense of security in the belief that once the individual has been treated, their risk of reoffending is reduced,” the authors wrote. “Current available evidence does not support this belief.”

--> Sex offenders who receive outpatient treatment are less likely to repeat offend than those who don’t receive this treatment, but the efficacy of sex offenders’ treatment while in prison is questionable at best. “Treatment varies widely — most programs combine cognitive behavioral therapy with lessons about empathy and anger management — and, in most cases, never ends,” writes Rachel Aviv in the New Yorker.

References

2. NCBI

George W. Archibald

Posted date: 12:02 PM / comment : 0

George William Archibald (born 13 July 1946) is the co-founder of the International Crane Foundation and was the inaugural winner of the 2006 Indianapolis Prize. Archibald was born in New Glasgow, Nova Scotia, Canada to Donald Edison and Annie Letitia ("Lettie") (née MacLeod) Archibald. He received his bachelor's degree from Dalhousie University in 1968 and his doctorate in 1975 from Cornell University. He married Kyoko Matsumoto on 15 August 1981. [Reference: Bergquist, Lee (22 August 2006) "Crane conservationist to receive $100,000 prize" Milwaukee Journal Sentinel (Wisconsin), page B-1].
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The Man Who Saves Cranes

George Archibald was awarded the $100,000 Lufkin Prize from National Audubon in recognition of his long career in conservation. It’s Archibald, as much as anyone, who is responsible for the whooping crane’s long, slow climb back from the brink of extinction. A pivotal moment in that return can be traced back 37 years, to an individual whooping crane going through an identity crisis. 
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In 1973, when cranes were in a perilous situation and many of the fifteen remaining species were on the brink of extinction, Archibald founded the International Crane Foundation in Baraboo, Wisconsin. He was Director from 1973 to 2000. Currently he heads a World Conservation Union commission on crane survival. Forty years later, the world's cranes are still in a perilous situation.
At the time, during 1976, Tex was only one of 100 whooping cranes (Grus americana) left in the world, and the only female whooping crane in her home at the San Antonio Zoo, so experts of a young crane breeding program were desperate to get her to produce offspring. But since Tex had been hand-raised in captivity by humans, and thus had been accidentally "imprinted" to believe that she was human, she refused to mate with any male whooping crane.
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Archibald pioneered several techniques to rear cranes in captivity, including the use of crane costumes by human handlers. Archibald spent three years with a highly endangered whooping crane named Tex, acting as a male crane – walking, calling, dancing – to shift her into reproductive condition. Through his dedication and the use of artificial insemination, Tex eventually laid a fertile egg. As Archibald later recounted the tale on The Tonight Show he stunned the audience and host Johnny Carson with the sad end of the story – the death of Tex shortly after the hatching of her one and only chick.

Further Reading
The Man Who Saves Cranes

Postmortem Stability of Ebola Virus

Posted date: 9:14 PM / comment : 0 , , ,

Date:
February 12, 2015
Source:
NIH/National Institute of Allergy and Infectious Diseases
Summary:
To determine how long Ebola virus could remain infectious in a body after death, scientists sampled deceased Ebola-infected monkeys and discovered the virus remained viable for at least seven days. They also detected non-infectious viral RNA for up to 70 days post-mortem.

Abstract

The ongoing Ebola virus outbreak in West Africa has highlighted questions regarding stability of the virus and detection of RNA from corpses. We used Ebola virus–infected macaques to model humans who died of Ebola virus disease. Viable virus was isolated 7 days posteuthanasia; viral RNA was detectable for 10 weeks.
Joseph Prescott, Trenton Bushmaker, Robert Fischer, Kerri Miazgowicz, Seth Judson, and Vincent J. Munster
Author affiliations: National Institutes of Health, Hamilton, Montana, USA

 Research: 
The ongoing outbreak of Ebola virus (EBOV) infection in West Africa highlights several questions, including fundamental questions surrounding human-to-human transmission and stability of the virus. More than 20,000 cases of EBOV disease (EVD) have been reported, and >8,000 deaths have been documented (1). Human-to-human transmission is the principal feature in EBOV outbreaks; virus is transmitted from symptomatic persons or contaminated corpses or by contact with objects acting as fomites (2). Contact with corpses during mourning and funeral practices, which can include bathing the body and rinsing family members with the water, or during the removal and transportation of bodies by burial teams has resulted in numerous infections (3).
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Assessing the stability of corpse-associated virus and determining the most efficient sampling methods for diagnostics will clarify the safest practices for handling bodies and the best methods for determining whether a person has died of EVD and presents a risk for transmission. To facilitate diagnostic efforts, we studied nonhuman primates who died of EVD to examine stability of the virus within tissues and on body surfaces to determine the potential for transmission, and the presence of viral RNA associated with corpses.

The Study

We studied 5 cynomolgus macaques previously included in EBOV pathogenesis studies and euthanized because of signs of EVD and viremia. Two animals were infected with EBOV-Mayinga and 3 with a current outbreak isolate (Makona-WPGC07) (4).
Immediately after euthanasia, multiple samples were collected: oral, nasal, ocular, urogenital, rectal, skin, and blood (pooled in the body cavity) swab samples and tissue biopsy specimens: from the liver, spleen, lung, and muscle. Swabs were placed in 1 mL of culture medium and tissue samples were placed in 500 μL of RNAlater (QIAGEN, Valencia, CA, USA), or an empty vial for titration, before freezing at −80°C. Carcasses were placed in vented plastic containers in an environmental chamber at 27°C and 80% relative humidity throughout the study to mimic conditions in West Africa (5). At the indicated time points (<9 days for 2 animals and 10 weeks for 3 animals), swab and tissue samples were obtained and used for EBOV titration on Vero E6 cells to quantify virus or for quantitative reverse transcription PCR (qRT-PCR) (40 cycles) to measure viral RNA, as reported (6,7).
Viral RNA was detectible in all swab samples and tissue biopsy specimens at multiple time points (Figure 1). For swab samples (Figure 1, panel A), the highest amount of viral RNA was in oral, nasal, and blood samples; oral and blood swab specimens consistently showed positive results for all animals until week 4 for oral specimens and week 3 for blood, when 1 animal was negative for each specimen type. Furthermore, oral swab specimens had the highest amount of viral RNA after the first 2 weeks of sampling, although after the 4-week sampling time point, some samples from individual animals were negative.
In all samples, RNA was detectable sporadically for the entire 10-week period, except for blood, which had positive results for <9 weeks. Tissue samples were more consistently positive within the first few weeks after euthanasia (Figure 1, panel B). All samples from the liver and lung were positive for the first 3 weeks, and spleen samples were positive for the first 4 weeks, at which time lung and spleen samples were no longer tested because of decay and scarcity of tissue. Muscle sample results were sporadic: a sample from 1 animal was negative at the 1-day time point and at several times throughout sampling.
Figure 1. Presence and stability of Ebola virus RNA in deceased cynomolgus macaques. Swab (A) and tissue (B) specimen samples were obtained at the indicated time points, and viral RNA was isolated and used in a 1-step quantitative reverse transcription PCR with a primer/probe set specific for the nucleoprotein gene and standards consisting of known nucleoprotein gene copy numbers. Line plots show means of positive samples from 5 animals up to the 7 day time point and from 3 animals thereafter. Error bars indicate SD, and - indicates time points at which ≥1 animal had undetectable levels of viral RNA at that time point. Absence of a hyphen indicates that all animals had detectible levels of viral RNA.
Figure 2. Efficiency of Ebola virus isolation from deceased cynomolgus macaques. Swab (A) and tissue (B) specimen samples were obtained at the indicated time points, and virus isolation was attempted on Vero E6 cells. Cells were inoculated in triplicate with serial dilutions of inoculum from swab specimens placed in 1 mL of medium or tissues homogenized in 1 mL of medium. The 50% tissue culture infectious dose (TCID50) was calculated by using the Spearman-Karber method (8). Line plots show means of positive samples from 5 animals to the day 9 time point. Error bars indicate SD.

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Viable EBOV was variably isolated from swab from all sampling sites. Among blood samples, those from the body cavity had the highest virus titer (2 × 105 50% tissue culture infectious doses/mL) and longest-lasting isolatable virus (7 days posteuthanasia) (Figure 2, panel A). Consistent with the qRT-PCR results, for swab samples, oral and nasal sample titers were highest, followed by those for blood samples, and relatively high titers were observed <4 days posteuthanasia (Figure 2, panel B). Similar to the qRT-PCR experiments, virus titers were higher in tissue samples than in swab samples but were not as sustained; all tissue samples were positive at day 3 posteuthanasia but negative by day 4.

Conclusions

The efficiency of detecting EBOV from corpse samples has not been systematically studied; this information is needed for interpreting results for diagnostic samples for epidemiologic efforts during outbreaks. We showed that viral RNA is readily detectable from oral and blood swab specimens for <3 weeks postmortem from a monkey carcass that was viremic at the time of death, in environmental conditions similar to those during current outbreak (5).
The stability of the target RNA used for RT-PCR is more robust than that of viable virus because degradation of any part of the genome (or proteins and lipids) would compromise the ability of the virus to replicate. Thus, the ability to isolate replicating virus in cell culture from postmortem materials was much less sensitive than detection of viral RNA by qRT-PCR. The sensitivity for quantitating infectious virus is probably lowered because of limitations in isolation efficiency on cell culture and necessary dilutions of tissues for homogenization for titration. Nonetheless, we detected viable virus <7 days posteuthanasia in swab specimens and 3 days in tissues, and showed that infectious virus is present at least until these times. Because virus titers decreased relatively sharply, despite sensitivity issues, it is unlikely that viable virus persists for times longer than we measured.
Humans who die of EVD typically have high levels of viremia, suggesting that most fresh corpses contain high levels of infectious virus, similar to the macaques in this study (9). Furthermore, family members exposed to EVD patients during late stages of disease or who had contact with deceased patients have a high risk for infection (2). The presence of viable EBOV and viral RNA in body fluids of EVD patients has been studied, and oral swabbing has been shown to be effective for diagnosis of EVD by RT-PCR compared with testing of serum samples from the same persons (10,11). However, detection limits for diagnostic swab samples are unknown for early phases of EVD, and blood sampling is probably more sensitive and reliable for antemortem diagnostics and should be used whenever possible, which has also been shown with closely related Marburg virus (12).
Although these studies included data from outbreak situations, they are limited in their sampling numbers, swabbing surfaces, and time course, and it is unknown how predictive they are for samples collected postmortem. It is essential to stress that swab samples should be obtained by vigorous sampling to acquire sufficient biologic material for testing, and development of a quality-control PCR target (housekeeping gene target) would be beneficial for sample integrity assessment, which is a limitation of this study.
In summary, we present postmortem serial sampling data for EBOV-infected animals in a controlled environment. Our results show that the EBOV RT-PCR RNA target is highly stable, swabbing upper respiratory mucosa is efficient for obtaining samples for diagnostics, and tissue biopsies are no more effective than simple swabbing for virus detection. These results will directly aid interpretation of epidemiologic data collected for human corpses by determining whether a person had EVD at the time of death and whether contact tracing should be initiated. Furthermore, viable virus can persist for >7 days on surfaces of bodies, confirming that transmission from deceased persons is possible for an extended period after death. These data are also applicable for interpreting samples collected from remains of wildlife infected with EBOV, especially nonhuman primates, and to assess risks for handling these carcasses.
Dr. Prescott is a research fellow in the Virus Ecology Unit at Rocky Mountain Laboratories, Hamilton, Montana. He is currently involved in the Ebola virus outbreak at the combined Centers for Disease Control and Prevention/National Institutes of Health diagnostic laboratory, Monrovia, Liberia. His research interests include the immune response, transmission, and modeling of viral hemorrhagic fevers.

Acknowledgments


We thank Darryl Falzarano and Andrea Marzi for use of animal carcasses upon completion of their studies and Anita Mora for providing assistance with graphics.
This study was supported by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health.

References

  1. Centers for Disease Control and Prevention. Ebola hemorrhagic fever [cited 2015 Jan 3]. http://www.cdc.gov.ezproxy.nihlibrary.nih.gov/vhf/ebola/
  2. Dowell SF, Mukunu R, Ksiazek TG, Khan AS, Rollin PE, Peters CJ. Transmission of Ebola hemorrhagic fever: a study of risk factors in family members, Kikwit, Democratic Republic of the Congo, 1995. J Infect Dis. 1999;179(Suppl 1):S87–91 . DOIPubMed
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    Suggested citation for this article: Prescott J, Bushmaker T, Fischer R, Miazgowicz K, Judson S, Munster VJ. Postmortem stability of Ebola virus. Emerg Infect Dis. 2015 May [date cited]. http://dx.doi.org/10.3201/eid2105.150041
    DOI: 10.3201/eid2105.150041

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