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Tuesday, October 28, 2014

Ebola can last on surfaces for almost TWO months, test reveal

Ebola can last on surfaces for almost TWO months, test reveal

  • 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 
  • 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. 

    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 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.

    The findings are also quoted in advice from the Public Agency of Health in Canada. 

    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 ļ¬loviruses 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)

    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. 


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