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Ebola
can survive on surfaces for almost TWO MONTHS: Tests reveal certain
strains survive for weeks when stored at low temperatures
- Research claims certain strains of Ebola can remain on surfaces for 50 days
- It survived the longest on glass surfaces stored at 4° (39°F)
- Centres for Disease Control and Prevention claims Ebola typically lives on a ‘dry’ surface for hours - including doorknobs and tables
- But when stored in moist conditions such in mucus, this is extended
- Survival time depends on the surface, and the room temperature
- Virus can be killed using household bleach and people must come into direct contact with the sample to risk infection
27
October, 2014
The
number of confirmed Ebola cases passed the 10,000 mark over the
weekend, despite efforts to curb its spread.
And
while the disease typically dies on surfaces within hours, research
has discovered it can survive for more than seven weeks under certain
conditions.
During
tests, the UK’s Defence Science and Technology Laboratory (DSTL)
found that the Zaire strain will live on samples stored on glass at
low temperatures for as long as 50 days.
+4
The
left-hand charts plot survival rates of Zaire strain of Ebola (Zebov)
and Lake Victoria marburgvirus (Marv) on glass (a) and plastic (b) at
4° (39°F) over 14 days. The right-hand charts reveal the survival
rate under the same conditions over 50 days. Both viruses survived
for 26 days, and Ebola was extracted after 50 days
The
tests were initially carried out by researchers from DSTL before
the current outbreak, in 2010, but the strain investigated is one of
five that is still infecting people globally.
Ebola
was discovered in 1976 and is a member of the Filoviridae family.
This
family includes the Zaire ebolavirus (Zebov), which was first
identified in 1976 and is the most virulent; Sudan ebolavirus,
(Sebov); Tai Forest ebolavirus; Ebola-Reston (Rebov), and Bundibugyo
ebolavirus (Bebov) - the most recent species, discovered in 2008.
HOW
LONG DOES EBOLA SURVIVE?
For
their 2010 paper, ‘The survival of filoviruses in liquids, on solid
substrates and in a dynamic aerosol’, the UK’s Defence Science
and Technology Laboratory (DSTL) tested two particular filoviruses on
a variety of surfaces.
These
were the Lake Victoria marburgvirus (Marv), and Zaire ebolavirus
(Zebov).
Each
was placed into guinea pig tissue samples and tested for their
ability to survive in different liquids and on different surfaces at
different temperatures, over a 50-day period.
When
stored at 4° (39°F), by day 26, viruses from three of the samples
were successfully extracted; Zebov on the glass sample, and Marv on
both glass and plastic.
By
day 50, the only sample from which the virus could be recovered was
the Zebov from tissue on glass.
For
their 2010 paper, ‘The survival of filoviruses in liquids, on solid
substrates and in a dynamic aerosol’, Sophie Smither and her
colleagues tested two particular filoviruses on a variety of
surfaces.
These
were the Lake Victoria marburgvirus (Marv), and Zebov.
Each
was placed into guinea pig tissue samples and tested for their
ability to survive in different liquids, and on different surfaces at
different temperatures, over a 50-day period.
When
stored at 4° (39°F), by day 26, viruses from three of the samples
were successfully extracted; Zebov on the glass sample, and Marv on
both glass and plastic.
By
day 50, the only sample from which the virus could be recovered was
the Zebov from tissue on glass.
‘This
study has demonstrated that filoviruses are able to survive and
remain infectious, for extended periods when suspended within liquid
and dried onto surfaces,’ explained the researchers.
‘Data
from this study extend the knowledge on the survival of filoviruses
under different conditions and provide a basis with which to inform
risk assessments and manage exposure.’
The
researchers do stress that these tests were carried out in a
controlled lab environment, and not in the real world, but published
their findings to highlight the survival rates.
Last
week the Centers for Disease Control and Prevention (CDC) updated its
Ebola guidelines following the rise in infections.
Ebola (pictured) was discovered in 1976 and is a member of the Filoviridae family. This family includes the Zaire ebolavirus (Zebov), which was first identified in 1976 and is the most virulent; Sudan ebolavirus, (Sebov); Tai Forest ebolavirus; Ebola-Reston (Rebov), and Bundibugyo ebolavirus (Bebov)
The
centre explained that Ebola is not spread through the air, water, or
food and a person infected with Ebola can’t spread the disease
until symptoms appear.
The
time from exposure to when signs or symptoms of the disease appear,
known as the incubation period, is two to 21 days, but the average
time is eight to 10 days.
HOW
TO PROTECT YOURSELF
The
Centres for Disease Control and Prevention advises:
•
DO
wash your hands often with soap and water or use an alcohol-based
hand sanitizer.
•
Do
NOT touch the blood or body fluids (like urine, feces, saliva, vomit,
sweat, and semen) of people who are sick.
•
Do
NOT handle items that may have come in contact with a sick person’s
blood or body fluids, like clothes, bedding, needles,or medical
equipment.
•
Do
NOT touch the body of someone who has died of Ebola.
Ebola
is spread through direct contact, through broken skin or through
eyes, nose, or mouth, via blood and body fluids of a person who is
sick with Ebola, or objects, such as needles, that have been
contaminated with the blood or body fluids of a person sick with
Ebola.
Signs
of Ebola include fever and symptoms like severe headache, muscle
pain, vomiting, diarrhea, stomach pain, or unexplained bleeding or
bruising.
Dr
Tom Fletcher of the Royal Army Medical Corps, who has treated victims
in Guinea and Sierra Leone, says: ‘The initial symptoms are quite
non-specific and similar to a flu-like illness.
'They
include fever, headache and lethargy. This progresses to severe
diarrhoea and vomiting.’
Officials
have emphasised there is no risk of transmission from people who have
been exposed to the virus, but are not yet showing symptoms.
But,
specialists at Emory University Hospital in Atlanta found that the
virus is present on a patient’s skin after symptoms develop,
underlining how contagious the disease is once symptoms set in.
According
to the CDC, the virus can survive for a few hours on dry surfaces
like doorknobs and countertops and can survive for several days in
puddles or other collections of body fluid.
However,
bleach solutions, including household bleach, can kill it.
Ebola
is only spread through direct contact, through broken skin or through
eyes, nose, or mouth, via blood and body fluids of a person who is
sick with Ebola, or objects, such as needles, that have been
contaminated with the blood or body fluids of a person sick with
Ebola. It can be killed using bleach
Ebola is only spread through direct contact, through broken skin or through eyes, nose, or mouth, via blood and body fluids of a person who is sick with Ebola, or objects, such as needles, that have been contaminated with the blood or body fluids of a person sick with Ebola. It can be killed using bleach
There is no FDA-approved vaccine available for Ebola, but experimental vaccines and treatments for Ebola are under development.
The CDC advises people wash their hands with soap and water or use an alcohol-based hand sanitiser, to protect themselves.
It warns to not touch the blood or body fluids, including urine, faeces, saliva, vomit, sweat, and semen of people who are sick.
Ebola was once thought to originated in gorillas, because human outbreaks began after people ate gorilla meat.
But scientists now believe that bats are the natural reservoir for the virus, and that apes and humans catch it from eating food that bats have drooled or defecated on, or by coming in contact with surfaces covered in infected bat droppings and then touching their eyes or mouths.
The current outbreak seems to have started in a village near Guéckédou, Guinea, where bat hunting is common, according to Doctors Without Borders
Officials
have emphasized that there is no risk of transmission from people who
have been exposed to the virus (pictured) but are not yet showing
symptoms. But, specialists at Emory University Hospital in Atlanta
found that the virus is present on a patient’s skin after symptoms
develop.
Ebola
was once thought to originated in gorillas, because human outbreaks
began after people ate gorilla meat. But scientists now believe that
bats are the natural reservoir for the virus, and that apes and
humans catch it from eating food that bats have drooled or defecated
on
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